Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

1. Organization
1.1 Organization Chart as of March 31, 2020 （End of FY2019）- 235 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

1.2 Topics in FY2019
Year

Date

Topics in Management

2019

Apr. 1

Newly appointed:
Deputy Director of RIKEN BNL Research Center: David MORRISON

2019

Apr. 1

Newly appointed:
Team Leader of Plant Genome Evolution Research Team: Tomoko ABE

2. Finances
A transition of the RNC budget for the past four years is shown in following graph.
Million Yen

3,500
3,000
2,500
2,000
1,500

3,060

3,199

2016

2017

2,877

2,824

2018

2019

1,000
500
0

3. Staffing
At the start of FY 2019, there were 142 personnel affiliated with RNC and 419 researchers visiting RNC for research purpose. The following
graphs show a breakdown of personnel into six categories as of April 1, 2019, and a transition of the number of each category.

73

Permanent Researcher

28

Contract Researcher
Technical staff

419

Special Postdoctoral Researcher
Junior Research Associate
External researcher

FY2019- 236 -

5

18
18

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

600

External researcher

500

Junior Research Associate

400
Special Postdoctoral
Researcher

300

Technical staff

200

Contract Researcher

100

Permanent Researcher

0

2016

2017

2018

2019

4. Research publication
The number of papers published annually from RNC is shown graphically using the data obtained from Clarivate Analytics’ Web of Science
Documents.

400
Source Documents

350
300
250
200
150
100
50
0

2016

2017

2018

2019

Publication Year
Citation analysis for the past four years
As of April 2020
Year
Indicators
Total number of papers

2016

2017

2018

2019

347

298

286

301

Percentage of papers in top 10%

15.85

16.78

20.63

9.63

Percentage of papers in top 1%

1.44

2.68

4.20

1.00

- 237 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

5. Management
Headed by the RNC Director Hideto En'yo, the RIKEN Nishina Center for Accelerator-Based Science (RNC) consists of:

9 Laboratories
10 Groups with 27 Teams
2 overseas research centers with 3 Groups

as of the end of FY2019. There are also two 'Partner Institutes' which conduct research in the laboratories set up in RNC. RNC is managed
by its Director who takes into consideration the majority decision of the RNC Coordination Committee. The management of RNC is supportedby the following committees:Program Advisory Committee
Safety Review Committee
RIBF Machine Time Committee
Public Relations Committee

There are also committees to support the President of RIKEN and/or the Director of RNC such as:

Nishina Center Advisory Council with three subcommittees:
・RBRC Scientific Review Committee (SRC)・International Advisory Committee for the RIKEN-RAL Muon Facility
・RBRC Management Steering Committee (MSC)

Nishina Center for Accelerator-based Science
Executive Members (as of March 31, 2020)
Hideto EN'YO
Director
Hiroyoshi SAKURAI
Deputy Director (Nuclear Science and Transmutation Research Division)
Osamu KAMIGAITO
Deputy Director (Research Facility Development Division)
Tomoko ABE
Deputy Director (Accelerator Application Division)
Yasushige YANO
Senior Advisor
Tohru MOTOBAYASHI
Senior Advisor
Hideyuki SAKAI
Senior Advisor

RNC Coordination Committee
The following subjects relevant to the RNC management are deliberated under the chairmanship of the RNC Director:






Establishment of the new organization or reorganization in RNC
Personnel management of RNC researchers
Research themes and research budget
Approval of the Partner Institutes
Evaluation of the management of RNC and the response to the recommendations by external evaluation

The RNC Coordination Committee is held monthly.
Members (as of March 31, 2020)
Hideto EN'YO
Director, RNC; Director, Radiation Laboratory
Hiroyoshi SAKURAI
Deputy Director, RNC; Director, Radioactive Isotope Physics Laboratory and Nuclear Transmutation Data ResearchGroup; Team Leader, Muon Date Team
Osamu KAMIGAITO
Deputy Director, RNC; Director, Accelerator Group and High-Intensity Accelerator R&D Group; Team Leader,
Infrastructure Management Team
Tomoko ABE
Deputy Director, RNC; Director, Beam Mutagenesis Group; Team Leader, Ion Beam Breeding Team and Plant
Yasushige YANO
Tohru MOTOBAYASHI
Hideyuki SAKAI
Tomohiro UESAKA
Hideki UENO
Toru TAMAGAWA
Kosuke MORITA
Yuko MOTIZUKI
Hiroki OKUNO

Genome Evolution Research Team

Senior Advisor, RNC
Senior Advisor, RNC
Senior Advisor, RNC
Director, Spin Isospin Laboratory and Research Instruments Group
Director, Nuclear Spectroscopy Laboratory and User Liaison Group; Team Leader, Outreach Team
Director, High Energy Astrophysics Laboratory
Director, Superheavy Element Research Group
Director, Astro-Glaciology Research Group
Deputy Group Director, Accelerator Group; Team Leader, Accelerator R&D Team, Cryogenic Technology Team, andHigh-Power Target R&D Team- 238 -

Ⅵ. RNC ACTIVITIESNobuhisa FUKUNISHI
Masanori WAKASUGIHiromitsu HABA
Tetsuo HATSUDA
Emiko HIYAMA
Masahiko IWASAKI
Kanenobu TANAKA
Koji MORIMOTO
Hideaki OTSU
Toshiyuki SUMIKAMA
Naruhiko SAKAMOTO
Takahide NAKAGAWA
Eiji IKEZAWA
Hironobu ISHIYAMA
Koichi YOSHIDA
Hidetada BABA
Hiromi SATO
Atsushi YOSHIDA
Ken-ichiro YONEDA
Yasuyuki AKIBA
Taku IZUBUCHI
Tsukasa TADA
Yutaka WATANABE
Yasushi WATANABE
Koichi ABE

RIKEN Accel. Prog. Rep. 53

Deputy Group Director, Accelerator Group; Team Leader, Beam Dynamics & Diagnostics Team
Director, Instrumentation Development Group; Team Leader, Rare RI-Ring Team and SCRIT Team
Director, RI Application Research Group; Team Leader, RI Application Team and Superheavy Element Production
Team
Director, Quantum Hadron Physics Laboratory
Director, Strangeness Nuclear Physics Laboratory
Director, Meson Science Laboratory
Director, Safety Management GroupTeam Leader, Superheavy Element Device Development Team
Team Leader, SAMURAI Team and Fast RI Data Team
Team Leader, Slow RI Data Team
Team Leader, Cyclotron Team and High-Gradient Cavity R&D Team
Team Leader, Ion Source Team
Team Leader, RILAC Team
Team Leader, SLOWRI Team
Team Leader, BigRIPS Team
Team Leader, Computing and Network Team
Team Leader, Detector Team
Team Leader, Industrial Application Research Team
Team Leader, RIBF User Liaison TeamGroup Leader, Experimental Group, RIKEN BNL Research Center
Group Leader, Computing Group, RIKEN BNL Research Center
Vice Chief Scientist, Quantum Hadron Physics Laboratory
Deputy Team Leader, Infrastructure Management Team
Deputy Team Leader, RIBF User Liaison Team
Director, Nishina Center and iTHEMS Promotion Office

Program Advisory Committee
The Program Advisory Committee reviews experimental proposals submitted by researchers and reports the approval/disapproval of the
proposals to the RNC Director. The Committee also reports to the RNC Director the available days of operation at RIBF or the Muon
Facility at RAL allocated to researchers. The Committee is divided into three categories according to the research field.


Nuclear Physics Experiments at RIBF (NP-PAC): academic research in nuclear physics
Materials and Life Science Researches at RNC (ML-PAC): academic research in materials science and life science
Industrial Program Advisory Committee (In-PAC): non-academic research

Program Advisory Committee for Nuclear Physics Experiments at RI Beam Factory (NP-PAC)
The 20th NP-PAC was held on December 16−18, 2019 at RIBF.
Members (as of March 31, 2020)
Robert V.F. JANSSENS (Chair)
Dieter ACKERMANN
Nori AOIMaria J.G. BORGE
Robert CHARITY
Augusto O. MACCHIAVELLI
Gabriel MARTINEZ-PINEDO
Iain MOOREDavid J. MORRISSEY
Hitoshi NAKADA
Alexandre OBERTELLITakehiko SAITO
Kimiko SEKIGUCHI
Philip J. WOODS
Andrea VITTURI
Xiaohong ZHOU

University of North Carolina at Chapel Hill
GANIL
Osaka University
Consejo Superior de Investigaciones Científicas
Washington University in St. Louis
Lawrence Berkeley National Laboratory
Technische Universität Darmstadt, GSI Helmholtzzentrum für Schwerionenforschung
University of Jyväskylä
Michigan State University
Chiba University
Technische Universität Darmstadt
RIKEN Cluster for Pioneering Research
Tohoku University
University of Edinburgh
Universita' di Padova
Institute of Modern Physics, CAS

Program Advisory Committee for Materials and Life Science Researches at RIKEN Nishina Center (ML-PAC)
The 18th and 19th ML-PAC was held on June 28, 2019 and January 24, 2020 at RIBF, respectively.
Members (as of March 31, 2020)
Adrian HILLIER (Chair)
Philippe MENDELS
Zhi QIN
Toshiyuki AZUMA
Ryosuke KADONOISIS, RAL (UK)
Laboratorie de Physique des Solides, Universite Paris (SUD)
Institute of Modern Physics, CAS
RIKEN Cluster for Pioneering ResearchInstitute of Materials Structure Science (KEK)- 239 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Atsushi KAWAMOTO
Shigeyuki KAWANO
Kenya KUBO
Hiroyuki YAMASE
Xu-Guang ZHENG
Robert V.F. JANSSENS

Hokkaido University
The University of Tokyo
International Christian University
Research Center for Functional Materials, NIMS
Saga University
University of North Carolina at Chapel Hill

Industrial Program Advisory Committee (In-PAC)
The 9th In-PAC was held on July 10, 2019 at RNC.

Safety Review Committee
The Safety Review Committee is composed of two sub committees, the Safety Review Committee for Accelerator Experiments and the HotLab Safety Review Committee. These Committees review the safety regarding the usage of radiation generating equipment based on the
proposal submitted to the RNC Director from the spokesperson of the approved experiment.
Safety Review Committee for Accelerator Experiments
Members (as of March 31, 2020)
Hiromi SATO (Chair)
Kouji MORIMOTO
Eiji IKEZAWA
Hiromitsu HABA
Atsushi YOSHIDA
Koichi YOSHIDA
Naoki FUKUDA
Naruhiko SAKAMOTO
Daisuke SUZUKI
Masaki SASANO
Yuichi ICHIKAWA

Team Leader, Detector Team
Team Leader, Superheavy Element Device Development Team
Team Leader, RILAC Team
Team Leader, RI Application Team
Team Leader, Industrial Cooperation Team
Team Leader, BigRIPS TeamTechnical Scientis, BigRIPS Team
Team Leader, Cyclotron Team
Research Scientist, Radioactive Isotope Physics Laboratory
Senior Research Scientist, Spin Isospin Laboratory
Senior Research Scientist, Nuclear Spectroscopy Laboratory

External members
Shinichiro MICHIMASA
Hidetoshi YAMAGUCHI
Yutaka WATANABE

Assistant Professor, Center for Nuclear Study, University of Tokyo
Lecturer, Center for Nuclear Study, University of Tokyo
Associate Professor, High Energy Accelerator Research Organization, KEK

Ex officio members
Kanenobu TANAKA
Hisao SAKAMOTO

Director, Safety Management Group
Technical Scientist, Safety Management Group

Hot-Lab Safety Review Committee
Members (as of March 31, 2020)
Kazuya TAKAHASHI (Chair)
Kanenobu TANAKA
Hisao SAKAMOTO
Hiroki MUKAI
Eriko HIGURASHI
Hiromitsu HABA
Tetsuya OHNISHI

Senior Research Scientist, Nuclear Chemistry Research Team
Director, Safety Management Group
Technical Scientist, Safety Management Group
Technical Staff I, Safety Management Group
Technical Scientist, Safety Management GroupTeam Leader, RI Application Team
Senior Research Scientist, SCRIT TeamRIBF Machine Time Committee
Upon request of the RNC Director, the RIBF Machine Time Committee deliberates on the machine time schedule of RIBF and reports theresults to the Director.
Members (as of March 31, 2020)
Hideki UENO (Chair)
Osamu KAMIGAITO
Masanori WAKASUGITomohiro UESAKA
Nobuhisa FUKUNISHI
Hiroki OKUNO
Hiroyoshi SAKURAI
Tomoko ABE

Director, User Liaison Group and Nuclear Spectroscopy Laboratory
Director, Accelerator Group
Director, Instrumentation Development Group
Director, Research Instruments Group and Spin Isospin Laboratory
Deputy Group Director, Accelerator Group
Deputy Group Director, Accelerator Group
Director, Radioactive Isotope Physics Laboratory
Director, Beam Mutagenesis Group- 240 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Hiromitsu HABA
Kanenobu TANAKA
Ken-ichiro YONEDA
Kouji MORIMOTO
Koichi YOSHIDA

Director, RI Application Research Group
Director, Safety Management GroupTeam Leader, RIBF User Liaison Team
Team Leader, Superheavy Element Research Device Development Team
Team Leader, BigRIPS Team

External members
Kentaro YAKO
Hidetoshi YAMAGUCHI
Yutaka WATANABE

Associate Professor, Center for Nuclear Study, University of Tokyo
Lecturer, Center for Nuclear Study, University of Tokyo
Associate Professor, High Energy Accelerator Research Organization, KEK

ObserversHideto EN'YO
Susumu SHIMOURA
Michiharu WADA
Kosuke MORITA
Hideaki OTSU
Atsushi YOSHIDA
Tohru MOTOBAYASHI
Hideyuki SAKAI
Kathrin WIMMER
Yasuhiro SAKEMI
Koichi ABE
Kazushige FUKUSHIMA

Director, RNC
Director, Center for Nuclear Study, University of Tokyo
Director, KEK Wako Nuclear Science Center
Director, Superheavy Element Research GroupTeam Leader, SAMURAI Team
Team Leader, Industrial Cooperation Team
Senior Advisor, RNC
Senior Advisor, RNC
Lecturer, University of Tokyo; Chair, The RIBF Users Executive Committee (RIBF-UEC)
Professor, Center for Nuclear Study, University of Tokyo
Director, Nishina Center and iTHEMS Promotion Office
Manager, Nishina Center and iTHEMS Promotion OfficePublic Relations Committee
Upon request of the RNC Director, the Public Relations Committee deliberates and coordinates the following matters:Creating public relations system for RNC
Prioritization of the public relations activities for RNC
Other general and important matters concerning the public relations of RNC

Members (as of March 31, 2020)
Koichi ABE (Chair)
Hiroyoshi SAKURAI
Osamu KAMIGAITO
Tomoko ABE
Tetsuo HATSUDA
Masahiko IWASAKI
Tomohiro UESAKA
Hideki UENO
Toru TAMAGAWA
Emiko HIYAMA
Kosuke MORITA

Director, Nishina Center and iTHEMS Promotion Office
Deputy Director, RNC; Director, Radioactive Isotope Physics Laboratory
Deputy Director, RNC; Director, Accelerator Group
Deputy Director, RNC; Director, Beam Mutagenesis Group
Director, Quantum Hadron Physics Laboratory
Director, Meson Science Laboratory
Director, Spin Isospin Laboratory and Research Instruments Group
Director, Nuclear Spectroscopy Laboratory and User Liaison Group
Director, High Energy Astrophysics Laboratory
Director, Strangeness Nuclear Physics Laboratory
Director, Superheavy Element Research Group

RBRC Management Steering Committee (MSC)
RBRC MSC is set up according to the Memorandum of Understanding between RIKEN and BNL concerning the collaboration on the Spin
Physics Program at the Relativistic Heavy Ion Collider (RHIC). The 25th MSC was held on May 24, 2019.
Members (as of May 24, 2019)
Motoko KOTANI
Tetsuo HATSUDA
Shoji NAGAMIYA
Robert TRIBBLE
Dmitori DENISOV
Berndt MUELLER

Executive Director, RIKEN
Program Director, RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program
Senior Visiting Scientist, RNC
Deputy Director for Science and Technology, BNL
Deputy Associate Laboratory Director for High Energy Physics, BNL
Associate Laboratory Director for Nuclear and Particle Physics, BNL

6. International Collaboration

Country

Partner InstituteObjects- 241 -

RNC contact person

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Austria

Stefan Meyer Institute forSubatomic Physics

Framework

Masahiko IWASAKI, Director, Meson Science
Laboratory

China

China Nuclear Physics Society

Creation of the council for China -Japan
research collaboration on nuclear physics

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Peking University

Nuclear Science

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Institute of Modern Physics,
Chinese Academy of Science

Physics of heavy ions

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

School of Nuclear Science andTechnology, Lanzhou University

Framework

Masahiko IWASAKI, Director, Meson Science
Laboratory

School of Physics, Nanjing
University

Framework

Emiko HIYAMA, Director, Strangeness Nuclear
Physics Laboratory

Department of Physics, Faculty of
Science, The University of Hong
Kong

Experimental and educational researchcollaboration in experimental nuclear physics

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

School of physics, Nankai
University

Framework

Emiko HIYAMA, Director, Strangeness Nuclear
Physics Laboratory

Finland

University of Jyvaskyla

Basic nuclear physics and related
instrumentation

Hironobu ISHIYAMA, Team Leader, SLOWRITeamFranceNational Institute of Nuclear
Physics and Particle Physics(IN2P3)

Physics of heavy ions

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

Normandy University

Framework

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

Technische Universität München

Nuclear physics, hadron physics, nuclear
astrophysics

Emiko HIYAMA, Director, Strangeness Nuclear
Physics Laboratory

GSI

Physics of heavy ions and accelerator

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Department of Physics,
Technische Universität Darmstadt

Framework

Emiko HIYAMA, Director, Strangeness Nuclear
Physics Laboratory

Hungary

The Institute of Nuclear Researchof the Hungarian Academy of
Sciences (ATOMKI)

Nuclear physics, Atomic Physics

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

Indonesia

ITB, UNPAD, ITS, UGM, UI

Material science using muons at the RIKENRAL muon facility

Masahiko IWASAKI, Director, Meson Science
Laboratory

Hasanuddin University

Agricultural science and related fields
involving heavy-ion beam mutagenesis using
Indonesian crops

Tomoko ABE, Director, Beam Mutagenesis Group

Applied Physics Division,
National Institute for New
Technologies, Energy andEnvironment (ENEA)

Framework

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

European Center for Theoretical
Studies in Nuclear Physics andRelated Areas (ECT*)

Theoretical physics

Tetsuo HATSUDA, Director, Quantum Hadron
Physics Laboratory

Istituto Nazionale di Fisica
Nucleare (INFN)

Physics of heavy ions

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Germany

Italy

Country

Partner InstituteObjects

RNC contact person

Seoul National University

Nishina School

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

College of Natural Science, Ewha
Women’s University

Framework

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

College of Natural Sciences,
INHA University

Framework

Emiko HIYAMA, Director, Strangeness Nuclear
Physics Laboratory

Malaysia

Universiti Sains Malaysia

Muon Science

Masahiko IWASAKI, Director, Meson Science
Laboratory

NorwayFaculty of Mathematics andNatural Science, University ofOslo（UiO MN）

Framework

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Korea- 242 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

PolandThe Henryk Niewodniczanski
Institute of Nuclear
Physics, Polish Academy of
Sciences(IFPAN)

Framework

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Romania“Horia Hulubei” National
Institute of Physics and Nuclear
Engineering Bucharest-Magurele,
Romania

Framework

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

University of Bucharest

Framework

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

Joint Institute for Nuclear
Research (JINR)

Framework

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

Russian Research Center“Kurchatov Institute”

Framework

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

Switzerland

Paul Scherrer InstituteImprove the performance and reliability ofaccelerator systems

Osamu KAMIGAITO, Director, Accelerator GroupUSA

Columbia University

The development of QCDCQ

Hideto EN’YO, Director, Radiation Laboratory

Michigan State University

Comprehensive
The use of TPC (Time Projection Chamber)

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

VietnamVietnam Atomic Energy
Commission

Framework

Hiroyoshi SAKURAI, Director, Radioactive Isotope
Physics Laboratory

EuropeEuropean Nuclear Science andApplication
Research2

Framework

Tomohiro UESAKA, Director, Spin Isospin
Laboratory

The European Organization for
Nuclear Research (CERN)

R&D and application of micro-pattern gas
detectors (MPGD) technology (RD51
Collaboration)

Hideto EN’YO, Director, Radiation Laboratory

The European Organization for
Nuclear Research (CERN)

Collaboration in the ALICE Experiment

Hideto EN’YO, Director, Radiation Laboratory

Russia7. Awards
Awardee, Laboratory / TeamAward

Organization

Date

Emiko HIYAMA, Director, Strangeness Nuclear Physics
Laboratory

The FY 2019 Prize for Science andTechnology, the Commendation for
Science and Technology by the
Minister of Education, Culture, Sports,
Science and Technology

The Minister of Education, Culture,
Sports, Science and Technology

Apr. 17

Daiki MORI, Technical Staff, Nuclear Chemistry
Research Team

Young Scientist Oral Presentation
Award at 56th Annual Meeting onRadioisotopes and Radiation
Researchers

Japan Radioisotope Association

Jul. 4

Nozomi SATO, Research Part-time Worker, Nuclear
Chemistry Research TeamIUPAC Periodic Table of Younger
Chemists

IUPAC

Jul. 8

Yasushi ABE, Visiting Scientist, Instrumentation
Development GroupThe 16th PASJ Annual Award forposter presentation

Particle Accelerator Society of Japan

Aug. 3

Akio TOMIYA, Special Postdoctoral Researcher,Computing GroupThe 13th Particle Physics Medal(FY2019): Young Scientist Award in
Theoretical Particle Physics

Particle Theory Committee

Sep. 19

Kosuke MORITA, Director, Superheavy Element
Research GroupThe 2019 Kimura Award

The Japan Society of Nuclear andRadiochemical Sciences (JNRS)

Sep. 25- 243 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Koichi YOSHIDA, Team Leader, BigRIPS TeamThe Saitama prefecture High-pressure
Gas Chairman Commendation

The Saitama prefecture High-pressure
Gas Committee

Oct. 23

A joint research group of RNC's Safety Management
Group and the Neutron Beam Technology Team of
RIKEN Center for Advanced Photonics

2019 Symposium on Nuclear Data
Poster Presentation Award

Atomic Energy Society of Japan
Nuclear Data Division

Nov.28

Tomoya NAITO, Student Trainee, Quantum Hadron
Physics Laboratory2020 CAEN Best Young Speaker
Award

Organizing Comettee of "Vth Topical
Workshop on Modern Aspects inNuclear Structure"

Feb. 8Hiromitsu HABA, Director, the RI Application Group

Open Innovation Prize(President of Science Council of Japan
Prize)

Cabinet Office, Government of Japan

Feb. 27- 244 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

8. Brief overview of the RI Beam Factory
Intensity of Primary Beams
Achieved beam intensities (as of March 2019)
238U

Xe
86
Kr
78Kr
70
Zn
48Ca
18O
14N
4He
d
pol. d124

94 pnA (345 MeV/nucleon, Nov. 2019)173 pnA (345 MeV/nucleon, Jun. 2019)30 pnA (345 MeV/nucleon, Nov. 2007)
486 pnA (345 MeV/nucleon, May. 2015)
250 pnA (345 MeV/nucleon, May 2017)730 pnA (345 MeV/nucleon, Nov. 2016)
1000 pnA (345 MeV/nucleon, Jun. 2010)
400 pnA (250 MeV/nucleon, Oct. 2010)
1000 pnA (250 MeV/nucleon, Oct. 2009)
1000 pnA (250 MeV/nucleon, Oct. 2010)
120 pnA, P~80% (250 MeV/nucleon, May 2015)

History of Beam Intensity Upgrade- 245 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Total beam time for experiments

Total beam time allocated to BigRIPS experiments- 246 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Radioactive Isotope Physics Laboratory
1. Abstract

This Laboratory works as one of core research groups conducting programs at the world-premiere heavy-ion accelerator facilityof RIKEN “RI Beam Factory (RIBF).” The Laboratory explores exotic nuclear structures and dynamics in exotic nuclei that havenever been investigated before, such as those with largely imbalanced proton and neutron numbers. Our aim is to develop new
experimental techniques utilizing fast radioactive isotope (RI) beams at RIBF, to discover new phenomena and properties in exotic
nuclei. The Laboratory is focusing three major subjects; shell evolution of very neutron-rich nuclei, the r-process path and equationof-state in asymmetric nuclear matter. The Laboratory has initiated international collaborations for in-beam gamma spectroscopy,
decay spectroscopy and heavy-ion induced reactions, and has formed a discussion forum for next generation gamma-ray detectors.

2. Major Research Subjects(1) Study of structure and dynamics of exotic nuclei through developments of new tools in terms of reaction- and technique-based
methodology(2) Research on EOS in asymmetric nuclear matter via heavy-ion induced reactions(3) Detector developments for spectroscopy and reaction studies

3. Summary of Research Activity(1) In-beam gamma spectroscopy
In the medium and heavy mass region explored at RIBF, collective natures of nuclei are one of important subjects, which are
obtained through production and observation of high excited and high spin states. To populate such states, heavy-ion induced reactions
such as fragmentation, fission are useful. So far, we have developed two-step fragmentation method as an eﬃcient method to identify
and populate excited states, and lifetime measurements to deduce transition strength.
Devices utilized for the in-beam gamma spectroscopy are ZeroDegree Spectrometer (ZDS) and a NaI array DALI2. Since the endof 2008, the first spectroscopy on nuclei island-of-inversion region was performed, we have explored step-by-step new and unknown
regions in the nuclear chart. The second campaign in 2009 was organized to study background components originating from atomic
processes in a heavy target. Neutron-rich nuclei at N = 20 to 28 were studied in 2010. In 2011–2013, we conducted experiment
programs for Ca-54, Ni-78, neutron-rich nuclei at N = 82 and neutron-deficient nuclei at Z = 50.
A multitude of data obtained with inelastic, nucleon knock-out, fragmentation channels have been analyzed and published. In
2011–2013, collective natures of Mg-36, 38 and Si-42 were both published in PRL. Excited states firstly observed in Ca-54 werereported in Nature to demonstrate a new nuclear magic number of 34. Fragmentation reaction has been found eﬃcient for nuclei
with A > 100 and low-lying excited state in Pd-126 has been successfully observed and reported in PRC. In 2019, results of the first
spectrosocpy of 40 Mg was published in PRL, to demonstrate the exotic structure which is very diﬀerent from in other neutron-rich Mg
isotopes.
To further strengthen the in-beam gamma spectroscopy at RIBF, we have proposed a new setup of MINOS + DALI2 to search
for the 1st excited states in even-even neutron-rich nuclei with Z ∼ 20 to 40. The program was submitted to the PAC 2013 as a
new category of proposal, “proposal for scientific program” and was S-ranked. A dedicated collaboration “SEASTAR” has been
established as a subset of in-beam gamma collaboration “SUNFLOWER.” The three campaigns were organized in 2014, 2015 and2017 to study very neutron-rich isotopes, and were very productive to access very neutron-rich nuclei such as Ar-52, Ca-56, Ni-78,
Kr-100, Zr-110. In 2019, the result of the first spectroscopy was published in Nature.
A new project of high resolution gamma spectroscopy with fast beams “HiCARI” has been proposed at PAC 2018 and thecampaign programs are scheduled in 2020. MINIBALL and several Ge tracking detectors from Japan, Europe, the USA and Korea
are being combined to form an array of germanium detectors. The new setup aims to accelerate researches of the nuclear structure byobserving gamma-lines in even-odd nuclei and measuring lifetimes of excited states. The two workshops were organized in 2019, andthe machine time of 43.5 days in total was approved at PAC 2019.
Concerning a next generation detector, a discussion forum has been established to write up a white paper on tracking germanium
detectors and high-eﬃcient crystal detectors such LaBr3 and GAGG.
(2) Decay spectroscopy
Beta- and isomer-spectroscopy is an eﬃcient method for studying nuclear structure, especially for non-yrast levels. We had
accumulated experimental techniques at the RIPS facility to investigate nuclear structure in light mass region via beta-gamma andbeta-p coincidence. Concerning the medium and heavy mass region available at RIBF, we have developed two position-sensitive
active-stoppers, strip-silicon detectors and a cylindrical active stopper called CAITEN, to achieve a low-background measurement by
taking correlation between heavy ion stop position and beta-ray emission position. A site of decay-spectroscopy at the new facility of
RIBF is the final focal plane of ZDS, where high precision of TOF in particle identification is obtained due to a long flight path fromBigRIPS to ZDS.
At the end of 2009, the first decay spectroscopy was organized with a minimum setup of four clover gamma detectors and silicon
strip detectors, to study neutron-rich nuclei with A ∼ 110. The first campaign was found successful and eﬃcient to publish four
letter articles in 2011, two PRL’s and two PLB’s. One of the PRL papers is associated to the r-process path where half-lives for 18- 247 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

neutron-rich nuclei were determined for the first time. The other PRL paper reported a finding of deformed magic number 64 in the
Zr isotopes.
The success of the first decay-spectroscopy campaign stimulated to form a new large-scale collaboration “EURICA,” where a
twelve Euroball cluster array is coupled with the silicon-strip detectors to enhance gamma eﬃciency by a factor of 10. A construction
proposal of “EURICA” was approved in the PAC 2011, and the commissioning was successfully organized in spring 2012. Since
then, physics runs had been conducted for programs approved to survey nuclei of interest as many as possible, such as Ni-78, Pd-128,
Sn-100. The EURICA collaboration finished its physics programs in summer 2016. So far, 54 papers including 14 PRL’s and 13
PLB’s were published. One of the highlights is discovery of a seniority isomer in Pd-128, of which cascade gamma decay gives theenergy of first excited state and robustness of N = 82 magic number, and the other is a half-life measurement for 110 neutron-richnuclei across the N = 82 shell gap, which shows implications for the mechanism and universality of the r-process path.
Beta-delayed neutron emission probability of medium and heavy neutron-rich nuclei is important to understand nuclear structure
and the r-process path. In 2013, a new collaboration “BRIKEN” has been established to form a He-3 detector array. A present
design of the array has neutron eﬃciency as high as 70% up to 3 MeV. The array was coupled with the AIDA silicon strip system. A
construction proposal was approved at the PAC 2013 and three physics proposals have been approved. The commissioning run was
conducted in autumn 2016. The major physics runs were conducted in 2017–2019.
The CAITEN detector was successfully tested with fragments produced with a Ca-48 beam in 2010.
(3) Equation-of-state via heavy-ion central collisions
Equation-of-state in asymmetric nuclear matter is one of major subjects in physics of exotic nuclei. Pi-plus and pi-minus yields
in central heavy ion collisions at the RIBF energy are considered as one of EOS sensitive observables at the RIBF energy. To observecharged pions, a TPC for the SAMURAI spectrometer is being constructed under an international collaboration “SπRIT,” Construction
proposal was submitted at the PAC 2012, and physics proposals were approved at the PAC 2012 and 2013. The physics runs weresuccessfully conducted in spring 2016. The data analysis is in progress to produce the first physics results.
An international symposium “NuSYM” on nuclear symmetry energy was organized at RIKEN July 2010 to invite researchers
in three sub-fields, nuclear structure, nuclear reaction and nuclear astrophysics, and to discuss nuclear symmetry energy together.
Since then, the symposium series have been held every year and been useful to encourage theoretical works and to strengthen thecollaboration.
(4) Nucleon correlation and cluster in nuclei
Nucleon correlation and cluster in nuclei are matters of central focus in a “beyond mean-field” picture. The relevant programswith in-beam gamma and missing-mass techniques are to depict nucleon condensations and correlations in nuclear media as a functionof density as well as temperature. Neutron-halo and –skin nuclei are objects to study dilute neutron matter at the surface. By changing
excitation energies in neutron-rich nuclei, clustering phenomena and role of neutrons are to be investigated.
In 2013, two programs were conducted at the SAMURAI spectrometer. One is related to proton-neutron correlation in the C-12
nucleus via p-n knockout reaction with a carbon target. The other is to search for a cluster state in C-16, which was populated via
inelastic alpha scattering. The data is being analyzed.
In 2018, a new project based on missing mass spectroscopy was launched to investigate an exotic cluster state in a very protonrich nucleus. The experiment was organized at GANIL with combination of RIKEN liquid hydrogen target CRYPTA and the MUST2
detector array in 2018.

Members
Group Director
Hiroyoshi SAKURAI (Deputy Director, RNC)
Special Temporary Research Scientist
Takashi ICHIHARA
Research/Technical Scientists
Yoichi NAKAI (Senior Research Scientist)
Tadaaki ISOBE (Senior Research Scientist)
Akihisa KOHAMA (Senior Research Scientist)

Pieter Christiaan DOORNENBAL (Senior Research Scientist)
Shunji NISHIMURA (Senior Research Scientist)
Daisuke SUZUKI (Research Scientist)

Research Consultants
Akitsu IKEDA
Masayasu ISHIHARA

Kenichi MATSUYANAGI
Hiroyuki MURAKAMI

Special Postdoctoral Researcher
Browne FRANK- 248 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Visiting Researcher
Alejandro ALGORA (JSPS)
Benoit J. C. MAUSS (JSPS)

Byul MOON (Nat’l Res. Foundation)

Junior Research Associates
Hideki SHIMIZU (Univ. of Tokyo)

Takuma KOIWAI (Univ. of Tokyo)

International Program Associates
Juan SAIZ LOMAS (Univ. of York)

Xiaohui SUN (Peking Univ.)

Senior Visiting Scientists
Koichiro ASAHI (Tokyo Tech)
Shigeru KUBONO (Univ. of Tokyo)

Kengo OGAWA (Chiba Univ.)

Visiting Scientists
Nori AOI (Osaka Univ.)
Giordano CERIZZA (Michigan State Univ.)
Jin-hee CHANG (Michigan State Univ.)
Silvio CHERUBINI (Univ. of Catania)
Martha Liliana CORTES SUA (INFN)
Mitsunori FUKUDA (Osaka Univ.)
Byungsik HONG (Korea Univ.)
Kazuo IEKI (Rikkyo Univ.)
Kei IIDA (Kochi Univ.)
Natsumi IKENO (Tottori Univ.)
Takuji IZUMIKAWA (Niigata Univ.)
Takashi KISHIDA (Aoyama Gakuin Univ.)
Gabor KISS (ATOMKI)
Khiem LE (Vietnam Academy of Sci. and Tech.)
Hiu Ching LEE (The Univ. of Hong Kong)
Giuseppe LORUSSO (Nat’l Phys. Lab.)
Alan MCINTOSH (Texas A & M Univ.)
Yoshiharu MORI (Kyoto Univ.)
Tetsuya MURAKAMI (Kyoto Univ.)

Megumi NIIKURA (Univ. of Tokyo)
Evgueni NIKOLSKI (Kurchatov Inst.)
Daiki NISHIMURA (Tokyo City Univ.)
Takashi OHTSUBO (Niigata Univ.)
Hooi Jin ONG (Osaka Univ.)
Akira ONO (Tohoku Univ.)
Naohiko OTSUKA (IAEA)
Kazuhiro OYAMATSU (Aichi Shukutoku Univ.)
Clementine Angelique Marie-Th SANTAMARIA (Berkeley
Lab)
Paer-Anders SOEDERSTROEM (TU Darmstadt)
Maya TAKECHI (Niigata Univ.)
Ryo TANIUCHI (Univ. of York)Rensheng WANG (Soochow Univ.)
Hiroshi WATANABE (Beihang Univ.)
Kathrin WIMMER (Inst.o de Estructura de la Materia, Consejo
Superior de Investigaciones Cientias, CSIC)
Jin WU (Argonne Nat’l Lab.)
Yasutaka YAMAMOTO (Osaka Univ.)

Visiting Technicians
Jorge AGRAMUNT ROS (Valencia city hall)
Hilde DE WITTE (KU Leuven)

Herbert E. HESS (Univ. of Cologne)
Ivan KOJOUHAROV (GSI)

Student Trainees
Takamichi AOKI (Univ. of Tokyo)
Takumi AOKI (Univ. of Tokyo)
Yusei BANDO (Univ. of Tokyo)
Jonathan BARNEY (Michigan State Univ.)
Linh BUI (Vietnam Atomic Energy Inst.)
Justin B. ESTEE (Michigan State Univ.)
Hiroaki FUKUSHIMA (Rikkyo Univ.)
Shinnosuke KANAYA (Osaka Univ.)
Masanori KANEKO (Kyoto Univ.)
Jiseok KIM (Korea Univ.)
Asahi KOHDA (Osaka Univ.)

Kei KOKUBUN (Univ. of Tokyo)
Shunpei KOYAMA (Univ. of Tokyo)
Jung Woo LEE (Korea Univ.)
Thomas G. PARRY (Univ. of Surrey)
Takeshi SAITO (Univ. of Tokyo)
Hidaka TANABE (Tsukuba Univ.)
Chun Yuen TSANG (Michigan State Univ.)
Phong VI (VNU Univ. of Sci.)
Ryo WAKABAYASHI (Osaka Univ.)
Tik Tsun YEUNG (The Univ. of Hong Kong)
Naoya YOSHIDA (Univ. of Tokyo)

Part-time Worker
Kiyomi ARAI (Research Part-time Worker I)
Mie DOI (Research Part-time Worker I)
Masanori KANEKO (Research Part-time Worker I)
Miki KANOU (Research Part-time Worker I)

Noriko OKAYASU (Research Part-time Worker I)
Tsuneyo SUZUKI (Research Part-time Worker I)
Misuzu KANOU (Research Part-time Worker II)
Eiko MIZUMOTO (Research Part-time Worker II)- 249 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Original papers]
T. Lokotko, S. Leblond, J. Lee, P. Doornenbal, A. Obertelli, A. Poves, F. Nowacki, K. Ogata, K. Yoshida, G. Authelet, H. Baba, D. Calvet,
F. Chateau, S. Chen, A. Corsi, A. Delbart, J. Gheller, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi,
M. Niikura, H. Otsu, C. Peron, A. Peyaud, E. Pollacco, J. Rousse, H. Sakurai, C. Santamaria, Z. Xu, M. Sasano, Y. Shiga, S. Takeuchi,
R. Taniuchi, T. Uesaka, H. Wang, V. Werner, F. Browne, L. Chung, Z. Dombradi, S. Franchoo, F. Giacoppo, A. Gottardo, K. HadynskaKlek, Z. Korkulu, S. Koyama, Y. Kubota, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, S. Nishimura, L. Olivier,S. Ota, Z. Patel, E. Sahin, C. Shand, P. Soderstrom, I. Stefan, D. Steppenbeck, T. Sumikama, D. Suzuki, Z. Vajta, and J. Wu, “Shellstructure of the neutron-rich isotopes 69, 71, 73 Co,” Phys. Rev. C 101, 034314 (2020).
Y. Sun, A. Obertelli, P. Doornenbal, C. Barbieri, Y. Chazono, T. Duguet, H. Liu, P. Navratil, F. Nowacki, K. Ogata, T. Otsuka, F. Raimondi,
V. Soma, Y. Utsuno, K. Yoshida, N. Achouri, H. Baba, F. Browne, D. Calvet, F. Chateau, S. Chen, N. Chiga, A. Corsi, M. Cortes,
A. Delbart, J. M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray,
H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. Togano, T. Uesaka, K. Wimmer,
K. Yoneda, O. Aktas, T. Aumann, L. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. B. Gerst, J. Gibelin, K. Hahn, D. Kim, T. Koiwai,
Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Park, D. Rossi, E. Sahin,
D. Sohler, P. A. Soderstrom, S. Takeuchi, H. Tornqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang,
M. Yasuda, and L. Zanetti, ‘Restoration of the natural E(1/2+1 ) − E(3/2+1 ) energy splitting in odd-K isotopes towards N = 40,” Phys.
Lett. B 802, 135215 (2020).
V. Vaquero, A. Jungclaus, T. Aumann, J. Tscheuschner, E. Litvinova, J. Tostevin, H. Baba, D. Ahn, R. Avigo, K. Boretzky, A. Bracco,
C. Caesar, F. Camera, S. Chen, V. Derya, P. Doornenbal, J. Endres, N. Fukuda, U. Garg, A. Giaz, M. Harakeh, M. Heil, A. Horvat,
K. Ieki, N. Imai, N. Inabe, N. Kalantar-Nayestanaki, N. Kobayashi, Y. Kondo, S. Koyama, T. Kubo, I. Martel, M. Matsushita, B. Million, T. Motobayashi, T. Nakamura, N. Nakatsuka, M. Nishimura, S. Nishimura, S. Ota, H. Otsu, T. Ozaki, M. Petri, R. Reifarth,
J. Rodriguez-Sanchez, D. Rossi, A. Saito, H. Sakurai, D. Savran, H. Scheit, F. Schindler, P. Schrock, D. Semmler, Y. Shiga, M. Shikata,Y. Shimizu, H. Simon, D. Steppenbeck, H. Suzuki, T. Sumikama, D. Symochko, I. Syndikus, H. Takeda, S. Takeuchi, R. Taniuchi,
Y. Togano, J. Tsubota, H. Wang, O. Wieland, K. Yoneda, J. Zenihiro, and A. Zilges, “Fragmentation of single-particle strength aroundthe doubly magic nucleus 132 Sn and the position of the 0f5/2 proton-hole state in 131 In131,” Phys. Rev. Lett. 124, 022501 (2020).
M. Cortes, W. Rodriguez, P. Doornenbal, A. Obertelli, J. Holt, S. Lenzi, J. Menendez, F. Nowacki, K. Ogata, A. Poves, T. Rodriguez,
A. Schwenk, J. Simonis, S. Stroberg, K. Yoshida, L. Achouri, H. Baba, F. Browne, D. Calvet, F. Chateau, S. Chen, N. Chiga, A. Corsi,
A. Delbart, J. M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H. Liu, T. Motobayashi,
I. Murray, H. Otsu, V. Panin, N. Paul, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. Sun, Y. Togano, T. Uesaka, K. Wimmer,
K. Yoneda, O. Aktas, T. Aumann, L. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. B. Gerst, J. Gibelin, K. Hahn, D. Kim, T. Koiwai,
Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Park, D. Rossi,
E. Sahin, D. Sohler, P. A. Soderstrom, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada,
D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “Shell evolution of N = 40 isotones towards 60 Ca: First spectroscopy of 62 Ti,” Phys. Lett.
B 800, 135071 (2020).
M. Tanaka, M. Takechi, A. Homma, M. Fukuda, D. Nishimura, T. Suzuki, Y. Tanaka, T. Moriguchi, D. Ahn, A. Aimaganbetov, M. Amano,
H. Arakawa, S. Bagchi, K. Behr, N. Burtebayev, K. Chikaato, H. Du, S. Ebata, T. Fujii, N. Fukuda, H. Geissel, T. Hori, W. Horiuchi,
S. Hoshino, R. Igosawa, A. Ikeda, N. Inabe, K. Inomata, K. Itahashi, T. Izumikawa, D. Kamioka, N. Kanda, I. Kato, I. Kenzhina,
Z. Korkulu, Y. Kuk, K. Kusaka, K. Matsuta, M. Mihara, E. Miyata, D. Nagae, S. Nakamura, M. Nassurlla, K. Nishimuro, K. Nishizuka,
K. Ohnishi, M. Ohtake, T. Ohtsubo, S. Omika, H. Ong, A. Ozawa, A. Prochazka, H. Sakurai, C. Scheidenberger, Y. Shimizu, T. Sugihara, T. Sumikama, H. Suzuki, S. Suzuki, H. Takeda, Y. Tanaka, I. Tanihata, T. Wada, K. Wakayama, S. Yagi, T. Yamaguchi, R. Yanagihara, Y. Yanagisawa, K. Yoshida, and T. Zholdybayev, “Swelling of doubly magic 48 Ca core in Ca isotopes beyond N = 28,” Phys.
Rev. Lett. 124, 102501 (2020).
G. Zhang, H. Watanabe, G. Dracoulis, F. Kondev, G. Lane, P. Regan, P. A. Soderstrom, P. Walker, K. Yoshida, H. Kanaoka, Z. Korkulu,
P. Lee, J. Liu, S. Nishimura, J. Wu, A. Yagi, D. Ahn, T. Alharbi, H. Baba, F. Browne, A. Bruce, M. Carpenter, R. Carroll, K. Chae,
C. Chiara, Z. Dombradi, P. Doornenbal, A. Estrade, N. Fukuda, C. Griﬃn, E. Ideguchi, N. Inabe, T. Isobe, S. Kanaya, I. Kojouharov,
T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, T. Lauritsen, C. Lee, E. Lee, C. Lister, G. Lorusso, G. Lotay, E. McCutchan,
C. B. Moon, I. Nishizuka, C. Nita, A. Odahara, Z. Patel, V. Phong, Z. Podolyak, O. Roberts, H. Sakurai, H. Schaﬀner, D. Seweryniak,
C. Shand, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, S. Terashima, Z. Vajta, J. Valiente-Dobon, Z. Xu, and S. Zhu, “Interplay ofquasiparticle and vibrational excitations: First observation of isomeric states in 168 Dy and 169 Dy,” Phys. Lett. B 799, 135036 (2019).
L. Sinclair, R. Wadsworth, J. Dobaczewski, A. Pastore, G. Lorusso, H. Suzuki, D. Ahn, H. Baba, F. Browne, P. Davies, P. Doornenbal,
A. Estrade, Y. Fang, N. Fukuda, J. Henderson, T. Isobe, D. Jenkins, S. Kubono, Z. Li, D. Lubos, S. Nishimura, I. Nishizuka, Z. Patel,
S. Rice, H. Sakurai, Y. Shimizu, P. Schury, H. Takeda, P. Soderstrom, T. Sumikama, H. Watanabe, V. Werner, J. Wu, and Z. Xu,“Half-lives of 73 Sr and 76 Y and the consequences for the proton dripline,” Phys. Rev. C 100, 044311 (2019).
K. Nakano, Y. Watanabe, S. Kawase, H. Wang, H. Otsu, H. Sakurai, S. Takeuchi, Y. Togano, T. Nakamura, Y. Maeda, D. S. Ahn,
M. Aikawa, S. Araki, S. Chen, N. Chiga, P. Doornenbal, N. Fukuda, T. Ichihara, T. Isobe, S. Kawakami, T. Kin, Y. Kondo, S. Koyama,
T. Kubo, S. Kubono, M. Uesaka, A. Makinaga, M. Matsushita, T. Matsuzaki, S. Michimasa, S. Momiyama, S. Nagamine, M. Niikura,T. Ozaki, A. Saito, T. Saito, Y. Shiga, M. Shikata, Y. Shimizu, S. Shimoura, T. Sumikama, P. A. Soderstrom, H. Suzuki, H. Takeda,
R. Taniuchi, J. Tsubota, Y. Watanabe, K. Wimmer, T. Yamamoto, and K. Yoshida, “Isotope production in proton-, deuteron-, andcarbon-induced reactions on 93 Nb at 113 MeV/nucleon,” Phys. Rev. C 100, 044605 (2019).
S. Chen, J. Lee, P. Doornenbal, A. Obertelli, C. Barbieri, Y. Chazono, P. Navratil, K. Ogata, T. Otsuka, F. Raimondi, V. Soma, Y. Utsuno,
K. Yoshida, H. Baba, F. Browne, D. Calvet, F. Chateau, N. Chiga, A. Corsi, M. Cortes, A. Delbart, J. Gheller, A. Giganon, A. Gillibert,- 250 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

C. Hilaire, T. Isobe, J. Kahlbow, T. Kobayashi, Y. Kubota, V. Lapoux, H. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul,
W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, N. Achouri,
O. Aktas, T. Aumann, L. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. Gerst, J. Gibelin, K. Hahn, D. Kim, T. Koiwai, Y. Kondo,
P. Koseoglou, C. Lehr, B. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Park, D. Rossi, E. Sahin, D. Sohler,
P. Soderstrom, S. Takeuchi, H. Tornqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda,and L. Zanetti, “Quasifree neutron knockout from 54 Ca corroborates arising N = 34 Neutron magic number,” Phys. Rev. Lett. 123,
142501 (2019).
R. Yokoyama, R. Grzywacz, B. Rasco, N. Brewer, K. Rykaczewski, I. Dillmann, J. Tain, S. Nishimura, D. Ahn, A. Algora, J. Allmond,
J. Agramunt, H. Baba, S. Bae, C. Bruno, R. Caballero-Folch, F. Calvino, P. Coleman-Smith, G. Cortes, T. Davinson, C. Domingo-Pardo,
A. Estrade, N. Fukuda, S. Go, C. Griﬃn, J. Ha, O. Hall, L. Harkness-Brennan, J. Heideman, T. Isobe, D. Kahl, M. Karny, T. Kawano,
L. Khiem, T. King, G. Kiss, A. Korgul, S. Kubono, M. Labiche, I. Lazarus, J. Liang, J. Liu, G. Lorusso, M. Madurga, K. Matsui,
K. Miernik, F. Montes, A. Morales, P. Morrall, N. Nepal, R. Page, V. Phong, M. Piersa, M. Prydderch, V. Pucknell, M. Rajabali,
B. Rubio, Y. Saito, H. Sakurai, Y. Shimizu, J. Simpson, M. Singh, D. Stracener, T. Sumikama, R. Surman, H. Suzuki, H. Takeda,
A. Tarifeno-Saldivia, S. Thomas, A. Tolosa-Delgado, M. Wolinska-Cichocka, P. Woods, and X. Xu, “Strong one-neutron emission
from two-neutron unbound states in β decays of the r -process nuclei 86, 87 Ga,” Phys. Rev. C 100, 031302 (2019).
V. Phong, G. Lorusso, T. Davinson, A. Estrade, O. Hall, J. Liu, K. Matsui, F. Montes, S. Nishimura, A. Boso, P. Regan, R. Shearman,
Z. Xu, J. Agramunt, J. Allmond, D. Ahn, A. Algora, H. Baba, N. Brewer, C. Bruno, R. Caballero-Folch, F. Calvino, M. WolinskaCichocka, G. Cortes, I. Dillmann, C. Domingo-Pardo, A. Gargano, S. Go, C. Griﬃn, R. Grzywacz, L. Harkness-Brennan, T. Isobe,
A. Jungclaus, D. Kahl, L. Khiem, G. Kiss, A. Korgul, S. Kubono, K. Miernik, A. Morales, N. Nepal, M. Piersa, Z. Podolyak, B. Rasco,
K. Rykaczewski, H. Sakurai, Y. Shimizu, D. Stacener, T. Sumikama, H. Suzuki, H. Takeda, J. Tain, A. Tarifeno-Saldivia, A. TolosaDelgado, V. Vaquero, P. Woods, R. Yokoyama, and C. Yuan, “Observation of a µs isomer in 134
49 In85 : Proton-neutron coupling “southeast” of 132
50 Sn82 ,” Phys. Rev. C 100, 011302 (2019).
V. Vaquero, A. Jungclaus, J. Rodriguez-Sanchez, J. Tostevin, P. Doornenbal, K. Wimmer, S. Chen, E. Nacher, E. Sahin, Y. Shiga, D. Steppenbeck, R. Taniuchi, Z. Xu, T. Ando, H. Baba, F. Bello Garrote, S. Franchoo, A. Gargano, K. Hadynska-Klek, A. Kusoglu, J. Liu,
T. Lokotko, S. Momiyama, T. Motobayashi, S. Nagamine, N. Nakatsuka, M. Niikura, R. Orlandi, T. Saito, H. Sakurai, P. Soderstrom,
G. Tveten, Z. Vajta, and M. Yalcinkaya, “Inclusive cross sections for one- and multi-nucleon removal from Sn, Sb, and Te projectiles
beyond the N = 82 shell closure,” Phys. Lett. B 795, 356–361 (2019).
K. Wimmer, P. Doornenbal, W. Korten, T. Arici, P. Aguilera, A. Algora, T. Ando, H. Baba, B. Blank, A. Boso, S. Chen, A. Corsi,
P. Davies, G. de Angelis, G. de France, D. Doherty, J. Gerl, R. Gernhauser, D. Jenkins, S. Koyama, T. Motobayashi, S. Nagamine,
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[Review articles]୩಺ྏ, ᓎҪതّ, ʮ2 ॏຐ๏਺ͱͦͷഁΕ: χοέϧ 78 ͷΨϯϚઢ෼ޫ͕ղ໌ͨ͠ด֪ੑʯ, ʮ෺ཧՊֶ, ͜ͷ 1 ೥ 2020ʯ, ύϦςΟ2020 ೥ 1 ݄߸, pp.86–89, ‫ؙ‬ળग़൛, (2020).
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S. Kubono, T. Kawabata, N. Iwasa, J. J. He, and S. Q. Hou, “Experimental Challenge to the Cosmological Li Problem,” Proc. Int.
Conference on Nuclei in the Cosmos XV, ed. A. Formicola, et al., Springer Proceedings in Physics 219, 45–52 (2019).
S. Hayakawa, K. Abe, O. Beliuskina, S. M. Cha, K. Y. Chae, S. Cherubini, P. Figuera, Z. Ge, M. Gulino, J. Hu, A. Inoue, N. Iwasa,
D. Kahl, A. Kim, D. H. Kim, G. G. Kiss, S. Kubono, M. La Cognata, L. Lamia, M. Lattuada, E. J. Lee, J. Y. Moon, Sara Palmerini,
C. Parascandolo, S. Y. Park, D. Pierroutsakou, Rosario Gianluca Pizzone, G. G. Rapisarda, S. Romano, H. Shimizu, C. Spitaleri,
Xiaodong Tang, O. Trippella, Aurora Tumino, P. Vi, H. Yamaguchi, L. Yang, and N. T. Zhang “Cross section measurements of the7
Be(n, p)7 Li and the 7 Be(n, α)4 He reactions covering the big-bang nucleosynthesis energy range by the trojan horse method at CRIB,”
Proc. Int. Conference on Nuclei in the Cosmos XV, ed. A. Formicola, et al., Springer Proceedings in Physics 219, 33–38 (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

L. Lamia, C. Spitaleri, M. Mazzocco, S. Hayakawa, C. A. Bertulani, A. Boiano, C. Boiano, Carlo Broggini, Antonio Caciolli,
Rosanna Depalo, F. Galtarossa, G. L. Guardo, M. Gulino, S. Kubono, M. La Cognata, M. La Commara, G. La Rana, M. Lattuada,
Roberto Menegazzo, A. Pakou, C. Parascandolo, D. Piatti, D. Pierroutsakou, Rosario Gianluca Pizzone, S. Romano, G. G. Rapisarda,
M. L. Sergi, O. Sgouros, F. Soramel, V. Soukeras, E. Strano, D. Torresi, Aurora Tumino, H. Yamaguchi, F. L. Villante, and G. L. Zhang“The Cosmologically Relevant 7 Be(n, α)4 He Reaction in View of the Recent THM Investigations,” Proc. Int. Conference on Nuclei in
the Cosmos XV, ed. A. Formicola, et al., Springer Proceedings in Physics 219, 53–56 (2019).
H. Shimizu, D. Kahl, H. Yamaguchi, K. Abe, O. Beliuskina, S. M. Cha, K. Y. Chae, A. A. Chen, Z. Ge, S. Hayakawa, N. Imai, N. Iwasa,
A. Kim, D. H. Kim, M. J. Kim, S. Kubono, M. S. Kawag, J. Liang, J. Y. Moon, S. Nishimura, S. Oka, S. Y. Park, A. Psaltis, T. Teranishi,
Y. Ueno, and L. Yang, “Study on 26m Al(p, γ) reaction at the SNe temperature,” JPS Conf. Proc. 31, 011073 (2020).
S. Hayakawa, M. La Cognata, L. Lamia, H. Shimizu, L. Yang, H. Yamaguchi, K. Abe, O. Beliuskina, S. M. Cha, K. Y. Chae, S. Cherubini,
P. Figuera, Z. Ge, M. Gulino, J. Hu, A. Inoue, N. Iwasa, D. Kahl, A. Kim, D. H. Kim, G. Kiss, S. Kubono, M. La Commara,
M. Lattuada, E. J. Lee, J. Y. Moon, S. Palmerini, C. Parascandolo, S. Y. Park, D. Pierroutsakou, R. G. Pizzone, G. G. Rapisarda,
S. Romano, C. Spitaleri, X. D. Tang, O. Trippella, A. Tumino, P. Vi, and N. T. Zhang, “Experimental study on the 7 Be(n, p)7 Li and the7Be(n, α)4 He reactions for cosmological lithium problem,”JPS Conf. Proc. 31, 011036 (2020).

Presentations[International conferences/workshops]
H. Sakurai (invited), “In-flight radioactive isotope beam facilities and nuclear physics at RIKEN,” The First African Nuclear Physics
Conference (ANPC), Kruger, South Africa, July 1–5, 2019.
S. Nishimura (invited), “r-process studies at RIBF,” Nuclear and astrophysics aspects for the rapid neutron capture process in the era ofmultimessenger observations, ECT∗ , Trento, Italy, July 1–5, 2019.
S. Nishimura (invited), “Decay properties of exotic nuclei” China-Japan Collaboration Workshop on Nuclear Mass and Life for Unraveling
Mysteries of R-process, ITP-CAS, Beijing, China, October 9–13, 2019.
S. Nishimura (invited), “Ukakuren” JINA-CEE IReNA/NAOJ Workshop, National Astronomy Observation of Japan, Mitaka, Japan,
December 3-4 (2019).
T. Isobe (poster), “Measurement of Th-229 low lying isomeric state with MRTOF+TES system at RIKEN-RIBF,” 18th International
Workshop on Low Temperature Detectors (LTD18), Milano, Italy, July 22–26, 2019.
T. Isobe (invited), “Latest update on RIKEN facilities,” 9th International Symposium on Nuclear Symmetry Energy (NuSym2019), Danan,
Vietnam, September 30–October 4, 2019.
T. Isobe (oral), “Experimental study of hydrogen isotopes production in Sn+Sn RI collisions at 270 AMeV,” 9th International Symposium
on Nuclear Symmetry Energy (NuSym2019), Danan, Vietnam, September 30–October 4, 2019.
P. Doornenbal (invited), “Structure of exotic Calcium and Nickel isotopes,” 14th Asia Pacific Physics Conference, Kuching, Malaysia,
November 17–22, 2019.
P. Doornenbal (invited), “Exploring the terra incognita of exotic nuclei at RIKEN: past achievements and future endeavors,” VINANST-13,
Reu Island, Vietnam, August 7–9, 2019.
P. Doornenbal (invited), “Towards high-resolution in-beam Gamma-ray spectroscopy at the RIBF,” 27th International Nuclear Physics
Conference (INPC), Glasgow, UK, July 29–August 2, 2019.
P. Doornenbal (invited), “In-beam gamma-ray spectroscopy at RIKEN,” 1st African Nuclear Physics Conference (ANPC), Kruger National Park, South Africa, July 1–5, 2019.
P. Doornenbal (oral), “High resolution spectroscopy of 78 Ni,” High Resolution Gamma-ray Spectrosocpy at the RIBF Workhsop, Darmstadt, Germany, April 10–12, 2019.
P. Doornenbal (oral), “Technical Considerations,” High Resolution Gamma-ray Spectrosocpy at the RIBF Workhsop, Darmstadt, Germany, April 10–12, 2019.
D. Suzuki (invited), “Present and future of in-beam spectroscopy at RIBF,” Workshop on RI-beam Spectroscopy by Innovative Gaseous
Active Targets, Osaka, Japan, December 19–20, 2019.
D. Suzuki (invited), “Present and future of in-beam spectroscopy at RIBF,” Workshop on RI-beam Spectroscopy by Innovative Gaseous
Active Targets, Osaka, Japan, December 19–20, 2019.
D. Suzuki (oral), “Coulomb and quantum bubbles in heavy nuclei,” High Resolution Gamma-Ray Spectroscopy at the RIBF, Darmstadt,
Germany, April 10–12, 2019.
D. Suzuki (oral), “rp-process study at OEDO,” OEDO collaboration workshop, Wako, Japan, September 2, 2019.
D. Suzuki (oral), “Recent results from SUNFLOWER and future perspectives,” JSPS/NRF/NSFC A3 Foresight Program “Nuclear Physics
in the 21st Century” Joint Kickoﬀ Meeting, Kobe, Japan, December 6–7, 2019.
D. Suzuki (invited), “Present and future of in-beam spectroscopy at RIBF,” Workshop on RI-beam Spectroscopy by Innovative Gaseous
Active Targets, Osaka, Japan, December 19–20, 2019.
D. Suzuki (invited), “Present and future of in-beam spectroscopy at RIBF,” Workshop on RI-beam Spectroscopy by Innovative Gaseous
Active Targets, Osaka, Japan, December 19–20, 2019.
D. Suzuki (oral), “Coulomb and quantum bubbles in heavy nuclei,” High Resolution Gamma-Ray Spectroscopy at the RIBF, Darmstadt,
Germany, April 10–12, 2019.
D. Suzuki (oral), “rp-process study at OEDO,” OEDO collaboration workshop, Wako, Japan, September 2, 2019.
W. Horiuchi, S. Hatakeyama, A. Kohama (oral), “Nuclear “diﬀuseness” probed by proton-nucleus diﬀraction,” The 27th International- 254 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Physics Conference (INPC 2019), Glasgow, UK, July 29–August 2, 2019. (INPC 2019)
S. Kubono (invited), “Heavy element synthesis under explosive burning on neutron stars,” The 10th European Summer School on Experimental Nuclear Astrophysics Catania, INFN-LNS, June 16–23, 2019.
S. Kubono (invited), “Experimental approach to explosive H-burning in X-ray bursts and SNeII,” Workshop on origin of Elements andCosmic Evolution: From Big-Bang to Supernovae and Mergers, Beihang University, China, November 27–29, 2019.
K. Asahi (invited), “Experiment on nuclear EDMs,” KEK Workshop on Nucleon EDMs and Spin Structure 2020, KEK Tokai Campus,
Tokai, Ibaraki, Japan, January 11, 2020.
R. Taniuchi (oral), “Approaching the fifth island of inversion from the north” High Resolution Gamma-Ray Spectroscopy at the RIBF, TU
Darmstadt, Germany, April 10–12, 2019.
R. Taniuchi (oral), “In-beam gamma-ray spectroscopy of 78 Ni reveals its doubly magic character,” 27th International Nuclear Physics
Conference (INPC 2019), Glasgow, United Kingdom, July 29–August 2, 2019.
R. Taniuchi (oral), “Quest for shell quenching of N = 50 in doubly magic 78 Ni” 8th SUNFLOWER Workshop/HiCARI Workshop, Osaka,
September 26–28, 2019.
V. Phong (oral), “β-decay measurements of very neutron-rich isotopes around Mass A = 130 within the BRIKEN project at RIBF,” 15th
International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15), Kyoto, Japan, July 2–5, 2019.
V. Phong (oral), “Measurement of very neutron-rich beta delayed neutron emitters around mass A = 130 relevant to the astrophysicalr-process,” 9th International Symposium on Nuclear Symmetry Energy (NuSYM2019), Danang, Vietnam, September 30–October 4,
2019.
H. Shimizu (poster), “Study on 26m Al(p, γ) reaction at the SNe temperature,” Symposium on Origin of Matter and Evolution of Galaxies(OMEG15), Kyoto, Japan, July 2–5, 2019.
H. Shimizu (poster), “Isomeric 26 Al beam production with CRIB,” Nuclear Physics School For Young Scientists (NUSYS-2019), Lanzhou,
China, August 12–17, 2019.
T. Koiwai (oral), “Single-particle structure of 55 Ti and 57 Ti,” Workshop on high-resolution gamma-ray spectroscopy at the RIBF, Darmstadt, Germany, April 2019
T. Koiwai (oral), “In-beam γ-ray spectroscopy of 55 K and 55 Ca via neucleon knockout reactions,” International Nuclear Physics Conference (INPC 2019), Glasgow, UK, July–Augsut 2019
T. Koiwai (oral), “N = 34 beyond 54 Ca: Single-particle structure of 55, 57 Ti,” 8th SUNFLOWER Workshop and HiCARI Workshop (JSPS
A3Foresight), Osaka, Japan, August 2019.

[Domestic conferences/workshops]ᓎҪതّʢট଴ߨԋʣ,ʮRIBF Ͱͷ֩෺ཧ‫ڀݚ‬ʯ, ‫ڀݚ‬ձʮγϛϡϨʔγϣϯʹΑΔӉ஦ͷ‫ج‬ຊ๏ଇͱਐԽͷղ໌ʹ޲͚ͯʢQUCS2019ʣʯ,‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ॴڀݚ‬, ‫౎ژ‬, 2019 ೥ 12 ݄.
੢ଜढ़ೋʢ‫ޱ‬಄ൃදʣ, ʮr ϓϩηεͷ‫ڀݚ‬: ࣮‫ݧ‬త‫ͱূݕ‬௅ઓʯ, ‫ڀݚ‬ձʮ‫֩ࢠݪ‬෺ཧͰͭΉ͙ r ϓϩηεʯ, ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ݚ‬‫ॴڀ‬, ‫౎ژ‬, 2019 ೥ 5 ݄ 22–24 ೔.
P. Doornenbal (invited), “Recent results from SUNFLOWER and future plans,” RIBF Week, Wako, Japan, September 2–4, 2019.
P. Doornenbal (invited), “Results from SEASTAR III,” SAMURAI Workshop, Tokyo, Japan, August 30–31, 2019.
P. Doornenbal (oral), “Sunflower Status,” SUNFLOWER/HiCARI Workshop, Osaka, Japan, August 26–28, 2019.
P. Doornenbal (invited), “Probing the Nuclear Shell Closures far oﬀ Stability with In-Beam Gamma-Ray Spectroscopy,” JPS Spring
Meeting, Kyushu, Japan, March 14–17, 2019.
ᴳ‫ޱ‬༤ਔʢ‫ޱ‬಄ൃදʣ, ງ಺ব, খᖛ༸ԝ, ʮ൓ཅࢠ-‫ࢄ֩ࢠݪ‬ཚʹΑΔ‫ر‬ബ֩ີ౓ྖҬͷ୳ࡧʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ౦ࢁΩϟϯύε, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–20 ೔.
F. Browne (oral), “Coulomb excitation study of Se isotopes beyond N = 50,” 8th SUNFLOWER Workshop/HiCARI Workshop (JSPS
A3Foresight), Osaka, Japan, August 26–28, 2019.
୩಺ྏʢট଴ߨԋʣ, ʮ֩ม‫ʹܗ‬ରͯ͠ೋॏด֪Λ‫࣋͢ݎ‬Δ 78Niʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶʢΦϯϥΠϯ։࠵ʣ,2020 ೥ 3 ݄ 16–19 ೔.
Ѵ ߞҰ࿠ʢট଴ߨԋʣ, ʮ‫ࢠݪ‬ͷ EDM ͱ࣌ؒ൓సରশੑͷഁΕ—൓࣓ੑ‫ࢠݪ‬ͷ EDM Λத৺ʹʯ, ిࢠ EDM ‫ڀݚ‬ձ, ౦‫ژ‬େֶۨ৔Ωϟϯύε, ໨ࠇ, 2019 ೥ 12 ݄ 11 ೔.

[Seminars]
T. Isobe, “Overview of the RI Beam Facility (RIBF),” CNS Summer School 2019 (CNSSS19), Nishina Hall Riken Wako, August 21–27,
2019.
T. Isobe, “Experimental study of asymmetric dense nuclear matter Equation Of State by using heavy RI collisions at RIBF-SπRIT,” CNS
Summer School 2019 (CNSSS19), Nishina Hall Riken Wako, August 21–27, 2019.
S. Kubono, “Special lectures on nuclear astrophysics,” Department of Physics, Hong Kong University, April 15–18, 2019.
K. Asahi, “Electric dipole moments of diamagnetic atoms—Present status of experiments,” CNS Seminar, Hongo, Tokyo, Japan, June 13,
2019.
R. Taniuchi, “78 Ni revealed as a doubly magic stronghold against nuclear deformation,” 276th RIKEN RIBF Nuclear Physics Seminar,
Saitama, Japan, May 28, 2019.
R. Taniuchi, “In-beam gamma-ray spectroscopy of 78 Ni revealed its double magicity and shape-coexistence,” The RIBF Users Group
Thesis Award lecture, RIBF Week 2019, Saitama, September 3, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

AwardsP. Doornenbal, RIKEN BAIHO Award 2020, Achievement: In-beam γ-ray spectroscopy of the neutron-rich doubly-magic nucleus 78 Ni
R. Taniuchi, The RIBF Users Group Thesis Award, September 3, 2019.
୩಺ྏ, ୈ 14 ճʢ2020 ೥ʣ೔ຊ෺ཧֶձएख঑ྭ৆, 2020 ೥ 3 ݄ 18 ೔.
୩಺ྏ, ୈ 26 ճ‫֩ࢠݪ‬ஊ࿩ձ ৽ਓ৆, 2020 ೥ 3 ݄ 18 ೔.
V. Phong, ANPhA(and AAPPS DNP) award for Young Scientists at 9th International Symposium on Nuclear Symmetry Energy(NuSYM2019): 2nd prize.

Press releasesʮຐ๏਺‫ࣈۚʹڀݚ‬ౝ—͍ͭʹதੑࢠա৒ͳχοέϧ‫֩ࢠݪ‬ͷೋॏຐ๏ੑʹ݁࿦—ʯ, 2019 ೥ 5 ݄ 2 ೔.
ʮ৽ຐ๏਺ 34 ͷ৽ͨͳূ‫—ڌ‬தੑࢠϊοΫΞ΢τ൓ԠͰ୳ΔΧϧγ΢Ϝ-54 ͷด֪ߏ଄—ʯ, 2019 ೥ 10 ݄ 18 ೔.
ʮ‫ʹܹٸ‬๲ΕΔ‫—֩ࢠݪ‬Χϧγ΢ϜಉҐମͰ‫͔ͨͬͭݟ‬ҟৗͳ֩൒‫૿ܘ‬େ‫ݱ‬৅—ʯ, 2020 ೥ 3 ݄ 13 ೔.

Outreach activitiesᓎҪതّ, ʮ‫ݩ‬ૉͷਐԽͱม‫׵‬ʯ, 2019 ೥౓Ѷ԰ެຽ‫ؗ‬αΠΤϯεߨ࠲, 2019 ೥ 4–6 ݄.
ү෦஧ত, ʮՊֶऀʹͳΔͱ͍͏ࣄʙੈք࠷ઌ୺ͷ‫ͱڀݚ‬ະདྷʙʯ, ࡉాֶԂߨԋձ, ࡉాֶԂߴ౳ֶߍ, ࢤ໦, 2019 ೥ 6 ݄ 24 ೔.

Others[Software package]
A. Kohama, K. Iida, K. Oyamatsu, H. Iwase, Release of “kurotama0” update (ver. 3.0), Contribution of PHITS update to ver. 3.20,
March 2020.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Spin isospin Laboratory
1. Abstract
The Spin Isospin Laboratory pursues research activities putting primary focus on interplay of spin and isospin in exotic nuclei.
Understanding nucleosyntheses in the universe, especially those in r- and rp-processes is another big goal of our laboratory.
Investigations on isospin dependences of nuclear equation of state, spin-isospin responses of exotic nuclei, occurrence of various
correlations at low-densities, evolution of spin-orbit coupling are main subjects along the line. We are leading a mass measurement
project with the Rare RI Ring project, too. Through the experimental studies, we will be able to elucidate a variety of nuclear
phenomena in terms of interplay of spin and isospin, which will in turn, lead us to better understanding of our universe.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Direct reaction studies of neutron-matter equation of state
Study of spin-isospin responses with RI-beams
R-process nucleosynthesis study with heavy-ion storage ring
Application of spin-polarization technique to RI-beam experiments and other fields
Development of special targets for RI-beam experiments

3. Summary of Research Activity(1) Direct reaction studies of neutron matter equation of state
Direct reactions induced by light-ions serve as powerful tools to investigate various aspects of nuclei. We are advancing experimental programs to explore equation of state of neutron matter, via light-ion induced reactions with RI-beams.
(1-1) Determination of a neutron skin thickness by proton elastic scattering
A neutron skin thickness is known to have strong relevance to asymmetry terms of nuclear equation of state, especially to aterm proportional to density. The ESPRI project aims at determining density distributions in exotic nuclei precisely by proton elastic
scattering at 200–300 MeV/nucleon. An experiment for 132 Sn that is a flagship in this project has been successfully performed.
(1-2) Asymmetry terms in nuclear incompressibility
Nuclear incompressibility represents stiﬀness of nuclear matter. Incompressibility of symmetric nuclear matter is determined
to be 230 ± 20 MeV, but its isospin dependence still has a large uncertainty at present. A direct approach to the incompressibilityof asymmetric nuclear matter is an experimental determination of energies of isoscalar giant monopole resonances (GMR) in heavy
nuclei. We have developed, in close collaboration with Center for Nuclear Study (CNS) of University of Tokyo, an active gas target
for deuteron inelastic scattering experiments to determine GMR energies. The active gas target has been already tested with oxygen
and xenon beams at HIMAC and finally has been applied to a 132 Sn experiment at RIBF.
(1-3) Multi-neutron and α-cluster correlations at low densities
Occurrences of multi-neutron and α-cluster correlations are other interesting aspects of nuclear matter and define its low-density
behavior. The multi-neutron and α-cluster correlations can be investigated with the large-acceptance SAMURAI spectrometer. The
SAMURAI has been already applied to experiments to explore light neutron-rich nuclei close to the dripline. We plan to reinforce
experimental capabilities of the SAMURAI by introducing advanced devices such as MINOS (Saclay) and NeuLAND (GSI).
(1-4) Fission barrier heights in neutron-rich heavy nuclei
The symmetry energy has a strong influence on fission barrier heights in neutron-rich nuclei. Knowledge on the fission barrierheights, which is quite poor at present, is quite important for our proper understanding on termination of the r-process. We are planningto perform, in collaboration with the TU Munich group, (p, 2p)-delayed fission experiments at the SAMURAI to determine the fission
barrier heights in neutron-rich nuclei in Pb region.
(2) Study of spin-isospin responses with RI-beams
The study of spin-isospin responses in nuclei forms one of the important cores of nuclear physics. A variety of collective states,for example isovector giant dipole resonances, isobaric analogue states, Gamow-Teller resonances, have been extensively studied byuse of electromagnetic and hadronic reactions from stable targets.
The research opportunities can be largely enhanced with light of availabilities of radioactive isotope (RI) beams and of physics of
unstable nuclei. There are three possible directions to proceed. The first direction is studies of spin-isospin responses of unstable nuclei
via inverse-kinematics charge exchange reactions. A neutron-detector array WINDS has been constructed, under a collaboration of
CNS, Tokyo and RIKEN, for inverse kinematics (p, n) experiments at the RI Beam Factory. We have already applied WINDS to the(p, n) experiments for 12 Be, 132 Sn and plan to extend this kind of study to other exotic nuclei.
The second direction is studies with RI-beam induced charge exchange reaction. RI-beam induced reactions have unique properties which are missing in stable-beam induced reactions and can be used to reach the yet-to-be-discovered states. We have constructed
the SHARAQ spectrometer and the high-resolution beam-line at the RI Beam Factory to pursue the capabilities of RI-beam induced
reactions as new probes to nuclei. One of the highlights is an observation of β+ type isovector spin monopole resonances (IVSMR) in
208
Pb and 90 Zr via the (t, 3 He) reaction at 300 MeV/nucleon.
The third direction is studies of neutron- and proton-rich nuclei via stable-beam induced charge exchange reactions, which is
conducted under collaboration with Research Center for Nuclear Physics (RCNP), Osaka University. We have performed the double- 257 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

charge exchange 12 C(18 O, 18 Ne) 12 Be reaction at 80 MeV/nucleon to investigate structure of a neutron-rich 12 Be nucleus. Peaks corresponding to ground and excited levels in 12 Be have been clearly observed. Another double charge exchange reaction, (12 C, 12 Be(0+2 ))are being used to search for double Gamow-Teller resonances.
(3) R-process nucleosynthesis study with heavy-ion storage ring
Most of the r-process nuclei become within reach of experimental studies for the first time at RI Beam Factory at RIKEN. The
Rare RI Ring at RIBF is the unique facility with which we can perform mass measurements of r-process nuclei. Construction of theRare RI Ring started in FY2012 in collaboration with Tsukuba and Saitama Universities. A major part of the ring has been completed
and the commissioning run is planned in FY2014.
We are planning to start precise mass measurements of r-process nuclei soon. A series of experiments will start with nuclei in the
A = 80 region and will be extended to heavier region.
(4) Application of spin-polarization technique to RI-beam experiments and other fields
A technique to produce nuclear polarization by means of electron polarization in photo-excited triplet states of aromatic molecules
can open new applications. The technique is called “Tripletd-DNP.” A distinguished feature of Triplet-DNP is that it works under alow magnetic field of 0.1–0.7 T and temperature higher than 100 K, which exhibits a striking contrast to standard dynamic nuclear
polarization (DNP) techniques working in extreme conditions of several Tesla and sub-Kelvin.
We have constructed a polarized proton target system for use in RI-beam experiments. Recent experimental and theoretical studies
have revealed that spin degrees of freedom play a vital role in exotic nuclei. Tensor force eﬀects on the evolution of shell and possible
occurrence of p-n pairing in the proton-rich region are good examples of manifestations of spin degrees of freedom. Experimentswith the target system allow us to explore the spin eﬀects in exotic nuclei. It should be noted that we have recently achieved a proton
polarization of 40% at room temperature in a pentacene-d14 doped p-terphenyl crystal.
Another interesting application of Triplet-DNP is sensitivity enhancement in NMR spectroscopy of biomolecules. We started a
new project to apply the Triplet-DNP technique to study protein-protein interaction via two-dimensional NMR spectroscopy, in close
collaboration with biologists and chemists.
(5) Development of special targets for RI-beam experiments
For the research activities shown above, we are developing and hosting special targets for RI-beam experiments listed below:(a) Polarized proton target (described in (4))(b) Thin solid hydrogen target(c) MINOS (developed at Saclay and hosted by the Spin Isospin Laboratory)

Members
Director
Tomohiro UESAKA
Research/Technical Scientists
Masaki SASANO (Senior Research Scientist)
Ken-ichiro YONEDA (Senior Research Scientist)

Juzo ZENIHIRO (Senior Research Scientist)
Sarah NAIMI (Research Scientist)

Contract Researchers
Takeshi INOUE

Kenichiro TATEISHI

Postdoctoral Researcher
Junki TANAKA
Junior Research Associates
Tomoya HARADA

Shoichiro MASUOKAInternational Program Associates
Siwei HUANG (Peking Univ.)
Alexandra-Ionela STEFANESCU (Univ. of Bucharest)

Ionut-Catalin STEFANESCU (Univ. of Bucharest)
Hongfu LI (IMP, CAS)

Research Consultants
Harutaka SAKAGUCHI (Osaka Univ.)
Yasuyuki SUZUKI (Niigata Univ.)

Kazuko TANABE (Otsuma Women’s Univ.)

Senior Visiting Scientist
Hiroyuki SAGAWA (Univ. of Aizu)- 258 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Visiting Scientists
Hidetoshi AKIMUNE (Konan Univ.)
Didier BEAUMEL (CNRS IPN Orsay)
Konstanze BORETZKY (GSI)
Christoph CAESAR (GSI)
Anna CORSI (CEA Saclay)
Zsolt DOMBRADI (ATOMKI)
Zoltan ELEKES (ATOMKI)
Zsolt FULOP (ATOMKI)
Tatsuya FURUNO (Osaka Univ.)
Igor GASPARIC (Rudjer Boskovic Inst.)
Zhuang GE (IMP, CAS)
Alain GILLIBERT (CEA Saclay)
Valdir GUIMARAES (Inst. de Fisica da Univ. de Sao Paulo)
Zoltan HALASZ (ATOMKI)
Matthias HOLL (TRIUMF)
Kaori KAKI (Shizuoka Univ.)
Takahiro KAWABATA (Kyoto Univ.)
Yuma KIKUCHI (NIT, Tokuyama College)
Yosuke KONDO (Tokyo Tech.)
Zeren KORKULU (ATOMKI)
Attila KRASZNAHORKAY (ATOMKI)
Dorottya KUNNE SOHLER (ATOMKI)
Istvan KUTI (ATOMKI)
Valerie LAPOUX (CEA Saclay)
Yury LITVINOV (GSI)
Hongna LIU (TU Darmstadt)

Yohei MATSUDA (Tohoku Univ.)
Kenjiro MIKI (Tohoku Univ.)
Tetsuaki MORIGUCHI (Tsukuba Univ.)
Momo MUKAI (Tsukuba Univ.)
Takashi NAKAMURA (Tokyo Tech.)Alexandre OBERTELLI (TU Darmstadt)
Kazuyuki OGATA (Osaka Univ.)
Valerii PANIN (CEA Saclay)
Emanuel POLLACCO (CEA Saclay)
Kimiko SEKIGUCHI (Tohoku Univ.)
Haik SIMON (GSI)
Laszlo STUHL (ATOMKI)
Baohua SUN (Beihang Univ.)
Yelei SUN (TU darmstadt)
Shinji SUZUKI (Chinese Academy of Sci.)
Satoru TERASHIMA (Beihang Univ.)
Hans Toshihide TOERNQVIST (TU Darmstadt)
Yasuhiro TOGANO (Rikkyo Univ.)
Takashi WAKUI (QST)
He WANG (Tokyo Tech.)Takayuki YAMAGUCHI (Saitama Univ.)
Nobuhiro YANAI (Kyushu Univ.)
Zaihong YANG (Osaka Univ.)
Juzo ZENIHIRO (Kyoto Univ.)
Yuhu ZHANG (Chinese Academy of Sci.)

Visiting Technicians
Gilles AUTHELET (CEA Saclay)
Denis CALVET (CEA Saclay)
Alain DELBART (CEA Saclay)
Jean-Marc GHELLER (CEA Saclay)
Arnaud GIGANON (CEA Saclay)

Clement HILAIRE (CEA Saclay)
Daniel KOERPER (GSI)
Cedric PERON (CEA Saclay)
Jean-Yves ROUSSE (CEA Saclay)
Olivier TELLIER (CEA Saclay)

Student Trainees
Paul E. ANDRE (CEA Saclay)
Takanobu DOI (Kyoto Univ.)
Wenbo DOU (Saitama Univ.)
Naoki EBINA (Tokyo Tech.)
Shiyo EN’YO (Kyoto Univ.)
Yuuki FUJII (Tokyo Tech.)
Yuki FUJIKAWA (Kyoto Univ.)
Saiya FUJIWARA (Kyushu Univ.)
Jian GAO (Peking Univ.)
Daiki HAMAKAWA (Saitama Univ.)
Yuya HAMANO (Kyushu Univ.)
Yuto HIJIKATA (Kyoto Univ.)
Yuma HIRAI (Kyushu Univ.)
Shun HOSOI (Saitama Univ.)Nancy Anne Paul HUPIN (Univ. of Paris-Saclay)
Kento INABA (Kyoto Univ.)
Yasuto INADA (Saitama Univ.)
Daiki INOMOTO (Kyushu Univ.)
Minami INOUE (Tohoku Univ.)
Shunya ISHIDA (Tohoku Univ.)
Leo KAGESAWA (Tsukuba Univ.)
Daisuke KAJIKI (Saitama Univ.)
Hina KASAHARA (Kyushu Univ.)
Kenta KAWAHARA (Tohoku Univ.)
Yusuke KAWASHIMA (Kyushu Univ.)

Sho KITAYAMA (Tohoku Univ.)
Shuhei KIYOTAKE (Univ. of Miyazaki)
Hironori KOUNO (Kyushu Univ.)
Taishi KUBO (Kyushu Univ.)
Atsushi KURIHARA (Tokyo Tech.)
Hayato KUROSAWA (Tohoku Univ.)
Christopher LEHR (TU Darmstadt)
Pengjie LI (The Univ. of Hong Kong)
Zanetti LORENZO (TU Darmstadt)
Ryu MAEDA (Tohoku Univ.)
Riku MATSUMURA (Saitama Univ.)
Hareru MIKI (Tokyo Tech.)
Midori MIWA (Saitama Univ.)
Motoki MURATA (Kyoto Univ.)
Anna NAKAGAWA (Tohoku Univ.)
Shinnosuke NAKAI (Tohoku Univ.)
Mio NISHIMURA (Rikkyo Univ.)
Toui NISHIMURA (Univ. of Miyazaki)
Kotaro NONAKA (Univ. of Miyazaki)
Kyoko NOSAKA (Tohoku Univ.)
Shintaro OKAMOTO (Kyoto Univ.)
Su-yeon PARK (Ewha Womans Univ.)
Atsumi SAITO (Tokyo Tech.)
Yuko SAITO (Tohoku Univ.)
Daisuke SAKAI (Tohoku Univ.)- 259 -

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Shigehito SAKAKI (Kyushu Univ.)
Kosuke SAKANASHI (Osaka Univ.)
Akane SAKAUE (Kyoto Univ.)
Mamoru SAKAUE (Saitama Univ.)
Tetsuro SHIMADA (Tokyo Tech.)
Dora SZALKAI (Eotvos Lorand Univ.)
Kohei TAKAHASHI (Tokyo Tech.)
Yuta UTSUKI (Tohoku Univ.)

Vadim WAGNER (TU Darmstadt)
Atomu WATANABE (Tohoku Univ.)
Kohei YAMAMOTO (Tohoku Univ.)
Shinpei YAMANAGA (Univ. of Miyazaki)
Akira YASUDA (Tokyo Tech.)
Kenjiro YOKOTA (Saitama Univ.)
Yuuki YOSHITOME (Tokyo Tech.)
Jianwei ZHAO (Beihang Univ.)

Interns
Maruf ALI (Univ. of Surrey)
Richard CRANE (Univ. of Surry)George W. G. W. HUDSON-CHANG (Univ. of Surrey)

Assistants
Emiko ISOGAI
Asako TAKAHASHI

Yuri TSUBURAI

List of Publications & Presentations
Publications[Original papers]
Z. Elekes, Á. Kripkó, D. Sohler, K. Sieja, K. Ogata, K. Yoshida, P. Doornenbal, A. Obertelli, G. Authelet, H. Baba, D. Calvet, F. Château,
A. Corsi, A. Delbart, J. -M. Gheller, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi, H. Otsu,
C. Péron, A. Peyaud, E. C. Pollacco, J. -Y. Roussé, H. Sakurai, C. Santamaria, Y. Shiga, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang,
K. Yoneda, F. Browne, L. X. Chung, Zs. Dombrádi, F. Flavigny, S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadyńska-Klȩk, Z. Korkulu,
S. Koyama, Y. Kubota, J. Lee, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, M. Niikura, S. Nishimura, L. Olivier,S. Ota, Z. Patel, E. Sahin, C. Shand, P. -A. Söderström, I. Stefan, D. Steppenbeck, T. Sumikama, D. Suzuki, Zs. Vajta, V. Werner, J. Wu,
and Z. Xu, “Nuclear structure of 76 Ni from the (p, 2p) reaction,” Phys. Rev. C 99, 014312 (2019).
A. I. Chilug, V. Panin, D. Tudor, L. Trache, I. C. Stefanescu, A. E. Spiridon, A. Saastamoinen, Z. Halasz, T. Motobayashi, T. Uesaka,
K. Yoneda, H. Otsu, “Study of the 9C breakup through NP1412-SAMURAI29R1 experiment,” AIP Conf. Proc. 2076, 060001 (2019).
Z. H. Yang, F. M. Marqués, N. L. Achouri, D. S. Ahn, T. Aumann, H. Baba, D. Beaumel, M. Böhmer, K. Boretzky, M. Caamaño, S. Chen,
N. Chiga, M. L. Cortés, D. Cortina, P. Doornenbal, C. A. Douma, F. Dufter, J. Feng, B. Fernández-Dom’ınguez, Z. Elekes, U. Forsberg,
T. Fujino, N. Fukuda, I. Gašparić, Z. Ge, R. Gernhäuser, J. M. Gheller, J. Gibelin, A. Gillibert, B. M. Godoy, Z. Halász, T. Harada,
M. N. Harakeh, A. Hirayama, S. W. Huang, N. Inabe, T. Isobe, J. Kahlbow, N. Kalantar-Nayestanaki, D. Kim, S. Kim, M. A. Knösel,
T. Kobayashi, Y. Kondo, P. Koseoglou, Y. Kubota, I. Kuti, C. Lehr, P. J. Li, Y. Liu, Y. Maeda, S. Masuoka, M. Matsumoto, J. Mayer,
H. Miki, M. Miwa, I. Murray, T. Nakamura, A. Obertelli, N. Orr, H. Otsu, V. Panin, S. Park, M. Parlog, S. Paschalis, M. Potlog,
S. Reichert, A. Revel, D. Rossi, A. Saito, M. Sasano, H. Sato, H. Scheit, F. Schindler, T. Shimada, Y. Shimizu, S. Shimoura, I. Stefan,
S. Storck, L. Stuhl, H. Suzuki, D. Symochko, H. Takeda, S. Takeuchi, J. Tanaka, Y. Togano, T. Tomai, H. T. Törnqvsit. J. Tscheuschner,
T. Uesaka, V. Wagner, K. Wimmer, H. Yamada, B. Yang, L. Yang, Y. Yasuda, K. Yoneda, L. Zanetti, and J. Zenihiro, “Study of multineutron systems with SAMURAI spectrometer,” Springer Proc. Phys. 238, 529–534 (2020).
V. P. Ladygin, A. V. Averyanov, E. V. Chernykh, D. Enache, Yu. V. Gurchin, A. Yu. Isupov, M. Janek, J. -T. Karachuk, A. N. Khrenov,
D. O. Krivenkov, P. K. Kurilkin, N. B. Ladygina, A. N. Livanov, O. Mezhenska, S. M. Piyadin, S. G. Reznikov, Ya. T. Skhomenko,
A. A. Terekhin, A. V. Tishevsky, and T. Uesaka (DSS Collaboration), “Energy dependence of the vector Ay and tensor Ayy and Axx
analyzing powers in deuteron-proton elastic scattering at large scattering angles,” EPJ Web of Conferences 204, 01019 (2019).
O. Mezhenska, A. V. Averyanov, E. V. Chernykh, D. Enache, Yu. V. Gurchin, A. Yu. Isupov, M. Janek, J. -T. Karachuk, A. N. Khrenov,
D. O. Krivenkov, P. K. Kurilkin, V. P. Ladygin, N. B. Ladygina, A. N. Livanov, S. M. Piyadin, S. G. Reznikov, Ya. T. Skhomenko,
A. A. Terekhin, A. V. Tishevsky, T. Uesaka, and J. Urban (DSS Collaboration), “Study of the deuteron analyzing powers in dp elastic
scattering at the energy of 800 MeV”, EPJ Web Conf. 204 (2019) 10001(2019).
N. Paul, A. Obertelli, C. A. Bertulani, A. Corsi, P. Doornenbal, J. L. Rodriguez-Sanchez, G. Authelet, H. Baba, D. Calvet, F. Château,
S. Chen, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi,
M. Niikura, H. Otsu, C. Péron, A. Peyaud, E. C. Pollacco, J. -Y. Roussé, H. Sakurai, C. Santamaria, M. Sasano, Y. Shiga, D. Steppenbeck, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang, K. Yoneda, T. Ando, T. Arici, A. Blazhev, F. Browne, A. M. Bruce, R. Carroll,
L. X. Chung, M. L. Cortés, M. Dewald, B. Ding, Zs. Dombradi, F. Flavigny, S. Franchoo, F. Giacoppo, M. Górska, A. Gottardo,
K. Hadynska-Klek, Z. Korkulu, S. Koyama, Y. Kubota, A. Jungclaus, J. Lee, M. Lettmann, B. D. Linh, J. Liu, Z. Liu, C. Lizarazo,
C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, K. Moschner, S. Nagamine, N. Nakatsuka, C. Nita, S. Nishimura, C. R. Nobs,
L. Olivier, S. Ota, Z. Patel, Zs. Podolyák, M. Rudigier, E. Sahin, T. Y. Saito, C. Shand, P. -A. Söderström, I. G. Stefan, T. Sumikama,
D. Suzuki, R. Orlandi, V. Vaquero, Zs. Vajta, V. Werner, K. Wimmer, J. Wu, and Z. Xu, “Prominence of pairing in inclusive (p, 2p) and(p, pn) cross sections from neutron-rich nuclei,” Phys. Rev. Lett. 122, 162503 (2019).
X. Xu, M. Wang, K. Blaum, J. D. Holt, Yu. A. Litvinov, A. Schwenk, J. Simonis, S. R. Stroberg, Y. H. Zhang, H. S. Xu, P. Shuai, X. L. Tu,
X. H. Zhou, F. R. Xu, G. Audi, R. J. Chen, X. C. Chen, C. Y. Fu, Z. Ge, W. J. Huang, S. Litvinov, D. W. Liu, Y. H. Lam, X. W. Ma,
R. S. Mao, A. Ozawa, B. H. Sun, Y. Sun, T. Uesaka, G. Q. Xiao, Y. M. Xing, T. Yamaguchi, Y. Yamaguchi, X. L. Yan, Q. Zeng,
H. W. Zhao, T. C. Zhao, W. Zhang, and W. L. Zhan, “Masses of neutron-rich 52–54 Sc and 54, 56 Ti nuclides: The N = 32 subshell closurein scandium,” Phys. Rev. C 99, 064303 (2019).

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X. Xu, J. H. Liu, C. X. Yuan, Y. M. Xing, M. Wang, Y. H. Zhang, X. H. Zhou, Yu. A. Litvinov, K. Blaum, R. J. Chen, X. C. Chen,
C. Y. Fu, B. S. Gao, J. J. He, S. Kubono, Y. H. Lam, H. F. Li, M. L. Liu, X. W. Ma, P. Shuai, M. Si, M. Z. Sun, X. L. Tu, Q. Wang,
H. S. Xu, X. L. Yan, J. C. Yang, Y. J. Yuan, Q. Zeng, P. Zhang, X. Zhou, W. L. Zhan, S. Litvinov, G. Audi, S. Naimi, T. Uesaka,
Y. Yamaguchi, T. Yamaguchi, A. Ozawa, B. H. Sun, K. Kaneko, Y. Sun, and F. R. Xu, “Masses of ground and isomeric states of 101 In
and configuration-dependent shell evolution in odd-A indium isotopes,” Phys. Rev. C 100, 051303 (2019).
A. Corsi, Y. Kubota, J. Casal, M. Gomez-Ramos, A. M. Moro, G. Authelet, H. Baba, C. Caesar, D. Calvet, A. Delbart, M. Dozono,
J. Feng, F. Flavigny, J. -M. Gheller, J. Gibelin, A. Giganon, A. Gillibert, K. Hasegawa, T. Isobe, Y. Kanaya, S. Kawakami, D. Kim,
Y. Kiyokawa, M. Kobayashi, N. Kobayashi, T. Kobayashi, Y. Kondo, Z. Korkulu, S. Koyama, V. Lapoux, Y. Maeda, F. M. Marques,
T. Motobayashi, T. Miyazaki, T. Nakamura, N. Nakatsuka, Y. Nishio, A. Obertelli, A. Ohkura, N. A. Orr, S. Ota, H. Otsu, T. Ozaki,
V. Panin, S. Paschalis, E. C. Pollacco, S. Reichert, J. -Y. Rousse, A. T. Saito, S. Sakaguchi, M. Sako, C. Santamaria, M. Sasano,
H. Sato, M. Shikata, Y. Shimizu, Y. Shindo, L. Stuhl, T. Sumikama, Y. L. Sun, M. Tabata, Y. Togano, J. Tsubota, T. Uesaka, Z. H. Yang,
J. Yasuda, K. Yoneda, and J. Zenihiro, “Structure of 13 Be probed via quasi-free scattering,” Phys. Lett. B 797, 134843 (2019).
S. Chen, J. Lee, P. Doornenbal, A. Obertelli, C. Barbieri, Y. Chazono, P. Navrátil, K. Ogata, T. Otsuka, F. Raimondi, V. Som‘a, Y. Utsuno,
K. Yoshida, H. Baba, F. Browne, D. Calvet, F. Château, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J. -M. Gheller, A. Giganon,
A. Gillibert, C. Hilaire, T. Isobe, J. Kahlbow, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu,
V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer,
K. Yoneda, N. Achouri, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R. -B. Gerst, J. Gibelin, K. I. Hahn,
D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park,D. Rossi, E. Sahin, D. Sohler, P. -A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu,
H. Yamada, D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “Quasifree neutron knockout from 54 Ca corroborates arising N = 34 Neutron
magic number,” Phys. Rev. Lett. 123, 142501 (2019).
V. Ladygin, A. Averyanov, E. Chernykh, D. Enache, Y. Gurchin, A. Isupov, M. Janek, J. -T. Karachuk, A. Khrenov, D. Krivenkov,
P. Kurilkin, N. Ladygina, A. Livanov, O. Mezhenska, S. Piyadin, S. Reznikov, Y. Skhomenko, A. Terekhin, A. Tishevsky, and T. Uesaka,“Spin studies of the short-range correlations with polarized beams at JINR-nuclotron,” JPS Conf. Proc. 26, 023023 (2019).
M. L. Cortés, W. Rodriguez, P. Doornenbal, A. Obertelli, J. D. Holt, S. M. Lenzi, J. Menéndez, F. Nowacki, K. Ogata, A. Poves,
T. R. Rodrı́guez, A. Schwenk, J. Simonis, S. R. Stroberg, K. Yoshida, L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen,
N. Chiga, A. Corsi, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux,
H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano,
T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R. -B. Gerst, J. Gibelin,
K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner,
T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, D. Sohler, P. -A. Söderström, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang,
V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti, “Shell evolution of N = 40 isotones towards 60 Ca: First
spectroscopy of 62 Ti,” Phys. Lett. B 800, 135071 (2020).
H. N. Liu, A. Obertelli, P. Doornenbal, C. A. Bertulani, G. Hagen, J. D. Holt, G. R. Jansen, T. D. Morris, A. Schwenk, R. Stroberg,
N. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J. -M. Gheller,
A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin,
N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda,
O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R. -B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai,
Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi,
E. Sahin, D. Sohler, P. -A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada,
D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “How robust is the N = 34 subshell closure? first spectroscopy of 52 Ar,” Phys. Rev. Lett.
122, 072502 (2019).
J. Tanaka, C. Bertulani, and S. Typel, “Post-formation in alpha emission from nuclei,” EPJ Web Conf. 227, 01001 (2020).
T. Matsumoto, J. Tanaka, and K. Ogata, “Borromean feshbach resonance in 11 Li studied via 11 Li (p, p′ ),” Prog. Theor. Exp. Phys. 12,
123D02 (2019).
S. Bagchi, R. Kanungo, W. Horiuchi, G. Hagen, T. D. Morris, S. R. Stroberg, T. Suzuki, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil,
I. Dillmann, A. Estradé, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, S. Kaur, R. Knöbel, J. Kurcewicz, Y. A. Litvinov,
M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H. J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, M. Takechi,
J. Tanaka, Y. Tanaka, I. Tanihata, S. Terashima, J. Vargas, H. Weick, and J. S. Winfield, “Neutron skin and signature of the N = 14 shell
gap found from measured proton radii of 17–22 N,” Phys. Lett. B 790, 251–256 (2019).
S. Bagchi, R. Kanungo, W. Horiuchi, G. Hagen, T. D. Morris, S. R. Stroberg, T. Suzuki, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil,
I. Dillmann, A. Estradé, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, S. Kaur, R. Knöbel, J. Kurcewicz, Y. Litvinov,
M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H. J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, M. Takechi,
J. Tanaka, Y. Tanaka, I. Tanihata, S. Terashima, J. Vargas, H. Weick, and J. Stuart Winfield, “Measurement of proton-distribution radiiof neutron-rich nitrogen isotopes,” EPJ Web Conf. 223, 01003 (2019).
H. Kouno, Y. Kawashima, K. Tateishi, T. Uesaka, N. Kimizuka, and N. Yanai, “Non-pentacene polarizing agents with improved airstability for triplet dynamic nuclear polarization at room temperature,” J. Phys. Chem. Lett. 10, 2208–2213 (2019).
K. Nishimura, H. Kouno, K. Tateishi, T. Uesaka, K. Ideta, N. Kimizuka, and N. Yanai, “Triplet dynamic nuclear polarization of nanocrystals dispersed in water at room temperature,” Phys. Chem. Chem. Phys. 21, 16408–16412 (2019).
K. Tateishi, M. Negoro, H. Nonaka, A. Kagawa, S. Sando, S. Wada, M. Kitagawa, and T. Uesaka, “Dynamic nuclear polarization withphoto-excited triplet electrons using 6,13-diphenylpentacene,” Phys. Chem. Chem. Phys. 21, 19737–19741 (2019).
H. Kouno, K. Orihashi, K. Nishimura, Y. Kawashima, K. Tateishi, T. Uesaka, N. Kimizuka, and N. Yanai, “Triplet dynamic nuclear
polarization of crystalline ice using water-soluble polarizing agents,” Chem. Commum. 56, 3717–3720 (2020).

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L. Stuhl, M. Sasano, J. Gao, Y. Hirai, K. Yako, T. Wakasa, D. S. Ahn, H. Baba, A. I. Chilug, S. Franchoo, Y. Fujino, N. Fukuda, J. Gibelin,
I. S. Hahn, Z. Halasz, T. Harada, M. N. Harakeh, D. Inomoto, T. Isobe, H. Kasahara, D. Kim, G. G. Kiss, T. Kobayashi, Y. Kondo,
Z. Korkulu, S. Koyama, Y. Kubota, A. Kurihara, H. N. Liu, M. Matsumoto, S. Michimasa, H. Miki, M. Miwa, T. Motobayashi,
T. Nakamura, M. Nishimura, H. Otsu, V. Panin, S. Park, A. T. Saito, H. Sakai, H. Sato, T. Shimada, Y. Shimizu, S. Shimoura,
A. Spiridon, I. C. Stefanescu, X. Sun, Y. L. Sun, H. Suzuki, E. Takada, Y. Togano, T. Tomai, L. Trache, D. Tudor, T. Uesaka, H. Yamada,Z. Yang, M. Yasuda, K. Yoneda, K. Yoshida, J. Zenihiro, and N. Zhang, “Study of spin-isospin responses of radioactive nuclei with thebackground-reduced neutron spectrometer, PANDORA,” Nucl. Instrum. Methods Phys. Res. B 463, 189–194 (2020).
Y. Kubota, M. Sasano, T. Uesaka, M. Dozono, M. Itoh, S. Kawase, M. Kobayashi, C. S. Lee, H. Matsubara, K. Miki, H. Miya, Y. Ono,
S. Ota, K. Sekiguchi, T. Shima, T. Taguchi, T. L. Tang, H. Tokieda, T. Wakasa, T. Wakui, J. Yasuda, and J. Zenihiro, “Development ofa neutron detector with a high position resolution at intermediate energies,” Nucl. Instrum. Methods Phys. Res. A 914, 32–41 (2019).

[Books]H. Sagawa, N. Yoshida, 「量子コンピュータ」, 量子情報理論 第 3 版, 1–300 (2019).

[Proceedings]
T. Yamaguchi, N. Tadano, Y. Abe, M. Amano, Z. Ge, D. Kamioka, T. Moriguchi, D. Nagae, S. Naimi, A. Ozawa, F. Suzaki, S. Suzuki,
T. Suzuki, T. Uesaka, M. Wakasugi, K. Wakayama, and Y. Yamaguchi, “Development of a new in-ring beam monitor in the Rare-RI
Ring,” Nucl. Instrum. Methods Phys. Res. B 463, 241–243 (2019).

Presentations[International conferences/workshops]
H. Sagawa (invited), “Recent progress on single and double spin-isospin excitations,” Neutrino Nuclear Response 2019 (NNR19), RCNP,
Osaka, Japan, May 8–9, 2019.
H. Sagawa (Oral), “Single and double charge exchange excitations of spin-isospin mode,” Nuclear Structure and Dynamics (NSD2019),
Venice, Italy, May 13–17, 2019.
H. Sagawa (invited), “Three-body model for nuclei near and beyond drip line,” Theoretical Nuclear Physics in Padova, Italy, May 20–21,
2019.
S. Naimi (Oral), “First mass measurements with the rare-RI ring at RIBF/RIKEN for nuclear astrophysics,” 27th International Nuclear
Physics Conference 2019, Glasgow, UK, July 29–August 2, 2019.
S. Huang, Z. Yang, and M. Marques (poster), “Experimental study of 4n with 8 He(p, 2p) reaction,” International Nuclear Physics Conference Glasgow, UK, July 29–August 2, 2019.
J. Tanaka (invited), “Clear evidence of α clusters in the ground state of heavy nuclei,” The 27th International Nuclear Physics Conference
Glasgow, UK, July 29–August 2, 2019.
S. Naimi, D. Nagae, Y. Abe, Y. Yamaguchi, S. Omika, K. Inomata, H. Arakawa, S. Hosoi, Y. Inada, W. B. Dou, D. Kajiki, K. Nishimuro,
T. Kobayashi, T. Yamaguchi, D. Hamakawa, M. Mukai, T. Moriguchi, R. Kagesawa, D. Kamioka, A. Ozawa, F. Suzaki, S. Suzuki,
Z. Ge, C. Y. Fu, Q. Wang, M. Wang, S. Ota, S. Michimasa, N. Kitamura, S. Masuoka, D. S. Ahn, H. Suzuki, N. Fukuda, H. Takeda,
Y. Shimizu, Yu. A. Litvinov, G. Lorusso, P. Walker, Zs. Podolyk, M. Wakasugi, and T. Uesaka (Poster), “Mass measurement of neutronrich 122 Rh, 123, 124 Pd and 125 Ag nuclides with rare-RI ring at RIBF in RIKEN,” 28th International Nuclear Physics Conference 2019,
Glasgow, UK, July 29–August 2, 2019.
H. Sagawa (Oral), “Single and double charge exchange excitations of spin-isospin mode,” EPJ Web Conf. 223, 01053 (2019).
H. Sagawa (invited), “EoS from terrestrial experiments: static and dynamic polarizations of nuclear density+B12,” 9th International
Symposium on Nuclear Symmetry Energy (Nusym2019), Da Nang City, Vietnam, September 30–October 4, 2019.
J. Tanaka (invited), “Direct evidence of α clusters in the ground state of heavy nuclei,” The 4th International Workshop on Quasi-Free
Scattering with Radioactive-Ion Beams, October 13–18, 2019.
T. Uesaka, “Possibility of LOREX at RIBF,” LOREX Workshop, GSI, Germany, December12–13, 2019.
H. Sagawa (invited), “Recent topics of single and double phonon spin-isospin excitations,” Vth Topical Workshop on Modern Aspects inNuclear Structure, Bormio, Italy, February 4–9, 2019.
S. En’yo, “A large solid hydrogen target for the proton elastic scattering with high int ensity RI beams,” CLUSHIQ2020, Beppu, Japan,
January 23–24, 2020.

[Domestic conferences/workshops]
立石健一郎, 上坂友洋 (招待講演), 「光励起電子スピンを用いた動的核偏極—超偏極溶液 NMR に向けて」, 第 58 回 NMR 討論会(NMR 討論会・SEST 2019 連合大会), 川崎コンベンションホール, 川崎, 2019 年 11 月 7–9 日.
髙田秀佐, 上坂友洋, 立石健一郎, 吉岡瑞樹, 大竹淑恵, 若林泰生, NOPTREX コラボレーション (口頭発表), 「Triplet-DNP による陽子偏極を利用した中性子スピンフィルターの開発—小型中性子源 RANS での性能評価—」, 日本物理学会 2019 年秋季大会, 山形大学, 山形, 2019 年 9 月 17–20 日.
松村理久 (ポスター発表), 「核分裂生成核種 Sr-90 の陽子および重陽子誘起反応に関する研究」, 日本物理学会第 75 回年次大会, 名
古屋大学, 名古屋, 2020 年 3 月 16–19 日.
上坂友洋 (口頭発表), 「超偏極が拓く科学技術〜フェムト・テクノロジーの未来に向けて〜」, 理研-九大-福岡市-ISIT 連携シンポ
ジウム, 理研和光キャンパス, 和光, 2019 年 5 月 22 日.
上坂友洋 (口頭発表), 「Triplet-DNP enhanced NMR is just around the corner」, DSB プロジェクト年次報告会, 理研横浜キャンパス,鶴見, 2019 年 11 月 13 日.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

原田知也 (口頭発表), 「不安定核 132Sn の逆運動学陽子弾性散乱測定」, 日本物理学会第 75 回年次大会, 名古屋大学, 名古屋, 2020
年 3 月 16–19 日.
延與紫世 (口頭発表), 「大強度 RI ビーム実験のための固体水素標的の開発」, 日本物理学会第 75 回年次大会, 名古屋大学, 名古屋,2020 年 3 月 16–19 日.
土方佑斗 (口頭発表), 「大強度不安定核ビームの粒子識別のための Xe ガス検出器の開発」, 日本物理学会第 75 回年次大会, 名古屋
大学, 名古屋, 2020 年 3 月 16–19 日.

[Seminar]
上坂友洋 (口頭発表), 「核物質の多様性」, 物理学第二教室原子核ハドロン研究室セミナー京都大学, 京都, 2019 年 11 月 29 日.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Nuclear Spectroscopy Laborarory
1. Abstract

The research group has conducted nuclear-physics studies utilizing stopped/slowed-down radioactive-isotope (RI) beams mainly
at the RIBF facility. These studies are based on the technique of nuclear spectroscopy such as β-ray-detected NMR (β-NMR), γPAD (Perturbed Angular Distribution), laser, and Mössbauer among other methods that takes advantage of intrinsic nuclear properties
such as nuclear spins, electromagnetic moments, and decay modes. In particular, techniques and devices for the production of spincontrolled RI beams have been developed and combined to the spectroscopic studies, which enable high-sensitivity measurements ofspin precessions/resonances through a change in the angular distribution of radiations. Anomalous nuclear structures and propertiesof far unstable nuclei are investigated from thus determined spin-related observables. The group also aims to apply such techniques tointerdisciplinary fields such as fundamental physics and materials science by exploiting nuclear probes.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Nuclear spectroscopy utilizing spin-oriented fast RI beams
Nuclear/Atomic laser spectroscopy & SLOWRI R&DApplication of RI probes to materials science
Fundamental physics: Study of symmetry

3. Summary of Research Activity(1) Nuclear spectroscopy utilizing spin-oriented fast RI beams
Measurements of static electromagnetic nuclear moments over a substantial region of the nuclear chart have been conducted forstructure studies on the nuclei far from the β-decay stability. Utilizing nuclear spin orientation phenomena of RIs created in the
projectile-fragmentation reaction, ground- and excited-state electromagnetic nuclear moments been determined by means of the βray-detected nuclear magnetic resonance (β-NMR) and the γ-ray time diﬀerential perturbed angular distribution (γ-TDPAD) methods.
In particular, a new method developed for controlling spin in a system of rare RIs, taking advantage of the mechanism of the two-step
projectile fragmentation reaction combined with the momentum-dispersion matching technique, has been developed and employedmaking fully use of world’s highest intensity rare RIBs delivered from BigRIPS for rare isotopes.
(2) Nuclear/Atomic laser spectroscopy & SLOWRI R&D
The group has been conducting system development for nuclear laser spectroscopy from the following two approaches in orderto realize experiments for rare isotopes at RIBF. One is collinear laser spectroscopy for a large variety of elements using sloweddown RI beams produced via a projectile-fragmentation reaction, which can be achieved only by the universal low-energy RI-beamdelivery system, SLOWRI, under installation in collaboration with the SLOWRI Team. This slowed-down RI-beam scheme enables
to perform high-precision laser spectroscopy even with fast-fragmentation-based RIBs without the elemental limitation problematicin the ISOL-based RIBs.
The other approach is a new method utilizing superfluid helium (He II) as a stopping medium of energetic RI beams, in which thecharacteristic atomic properties of ions surrounded by superfluid helium enables us to perform unique nuclear laser spectroscopy. RIions trapped in He II are known to exhibit a characteristic excitation spectrum significantly blue-shifted compared with the emission
one. Consequently, the background derived from the excitation-laser stray light, which often causes serious problems in measurements,
can be drastically reduced.
(3) Application of RI probes to materials science
The application of RI and heavy ion beams as a probe for condensed matter studies is also conducted by the group. The microscopic material dynamics and properties have been investigated through the deduced internal local fields and the spin relaxation of
RI probes based on various spectroscopies utilizing RI probes such as β-NMR/NQR spectroscopy, Mössbauer spectroscopy, the γ-ray
time diﬀerential perturbed angular correlation (γ-TDPAC) spectroscopy. Furthermore, studies on the control of electrical conductivityof diamond by boron and nitrogen implantation are ongoing.
Provided that highly spin-polarized RI probes are produced independently of their element properties and doped into a substanceas an impurity, the constituent particle of the substance can be substituted by the same element RI probe without changing the material
structure. This scheme provides a new opportunity for materials-science researches, but a key technology, production of elementindependent highly spin-polarized RI beams, has not yet been achieved. In this subject, the group has conducted R&D studies torealize an ultra-slow & highly-spin-polarized RI beams, based on the technique of the atomic beam resonance.
(4) Fundamental physics: Study of symmetry
The nuclear spins of stable and unstable isotopes sometimes play important roles in fundamental physics research. New experimental methods and devices have been developed for studies of the violation of time reversal symmetry (T-violation) using spinpolarized nuclei. These experiments aim to detect the small frequency shift in the spin precession arising from new mechanisms
beyond the Standard Model.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Members
Director
Hideki UENO
Research/Technical Scientists
Hiroki YAMAZAKI (Senior Research Scientist)
Yuichi ICHIKAWA (Senior Research Scientist)

Aiko TAKAMINE (Research Scientist)

Research & Development Scientist
Tetsu SONODA
Special Postdoctoral Researcher
Hiroki NISHIBATA
Postdoctoral Researcher
Minori TAJIMA
Research Associate
Aleksey GLADKOV
Junior Research Associate
Keita KAWATA (Univ. of Tokyo)
Senior Visiting Scientists
Yukari MATSUO (Hosei Univ.)
Hideyuki SAKAI (Univ. of Tokyo)

Takaharu OTSUKA (Univ. of Tokyo)

Visiting Scientists
Dimiter Loukanov BALABANSKI (IHIN)
Georgi GEORGIEV (CNRS-IN2P3)
Kei IMAMURA (Okayama Univ.)
Yoko ISHIBASHI (Tohoku Univ.)
Yoshio KOBAYASHI (Univ. of Electro-Commun.)
Kenya KUBO (Int’l Christian Univ.)
Kensaku MATSUTA (Osaka Univ.)
Jun MIYAZAKI (Hokuriku Univ.)
Takamasa MOMOSE (The Univ. of British Columbia)
Jiro MURATA (Rikkyo Univ.)

Jin NAKAMURA (Univ. of Electro-Commun.)
Hiroki NISHIBATA (Kyushu Univ.)
Naoki NISHIDA (Tokyo Univ. Sci)
Tomoya SATO (Tokyo Tech)
Wataru SATO (Kanazawa Univ.)
Andrew E. STUCHBERY (The Australian Nat’l Univ.)
Satoshi TSUTSUI (Japan Synchrotron Radiation Res. Inst.)
Yasuhiro YAMADA (Tokyo Univ. Sci)
Deyan T. YORDANOV (Inst. de Phys.Nucl. d’Orsay)
Akihiro YOSHIMI (Okayama Univ.)

Student Trainees
Shota AMAGASA (Tokyo Univ. Sci)
Takumi ASAKAWA (Hosei Univ.)
Kazuho DOI (Hosei Univ.)
Miru DOI (Hosei Univ.)
Takumi FUNABASHI (Tokyo Univ. Sci)
Timothy J. GRAY (The Australian Nat’l Univ.)
Kentaro HAMANO (Univ. of Electro-Commun.)
Kazuki HAMAZAKI (Tokyo Univ. Sci)
Kyouichi IZUOKA (Tokyo Univ. Sci)
Masato KIJI (Univ. of Electro-Commun.)Naoki KOSHIKAWA (Tokyo Univ. Sci)

Masaki NISHIMURA (Hosei Univ.)
Shinichi OKAMURA (Univ. of Ferrara)David PELLETIER (ENSICAEN)
Yusuke SASAKI (Hosei Univ.)
Ryo TAKEMURA (Tokyo Univ. Sci)
Yuika TAKEUCHI (Hosei Univ.)
Kenta TSUBURA (Hosei Univ.)
Tomoaki YADA (Hosei Univ.)
Takumi YAMAMOTO (Hosei Univ.)
Fumiya YOKOSUKA (Aoyama Gakuin Univ.)

Interns
Chengyu GUO (Peking Univ.)
Chan HEO (The Univ. of Hong Kong)
Meng Chit HO (The Univ. of Hong Kong)
Ziyao HU (Peking Univ.)
Min Young KIM (Seoul Nat’l Univ.)
Minju KUM (Seoul Nat’l Univ.)
Euijoon KWON (Seoul Nat’l Univ.)
Joo Hyun LEE (Seoul Nat’l Univ.)
Pak Yi LI (The Univ. of Hong Kong)

Fumiya OURA (Tohoku Univ.)
Shoko TAKESHIGE (Rikkyo Univ.)
Masashi TAWARA (Rikkyo Univ.)
Hao WANG (Peking Univ.)
Sau Hei WONG (The Univ. of Hong Kong)
Seungbum WOO (Seoul Nat’l Univ.)
Lisheng YANG (Peking Univ.)
Ryan W. YEUNG (The Univ. of Hong Kong)
Zhenxiang ZHOU (Peking Univ.)

Temporary Staﬃng- 265 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Emiko FUJINO

Naoko YUASA

AssistantIzumi YOSHIDA

List of Publications & Presentations
Publications[Original papers]
M. Tajima, N. Kuroda, C. Amsler, H. Breuker, C. Evans, M. Fleck, A. Gligorova, H. Higaki, Y. Kanai, B. Kolbinger, A. Lanz, M. Leali,
V. Mäckel, C. Malbrunot, V. Mascagna, Y. Matsuda, D. Murtagh, Y. Nagata, A. Nanda, B. Radics, M. Simon, S. Ulmer, L. Venturelli,
E. Widmann, M. Wiesingerc, and Y. Yamazaki, “Antiproton beams with low energy spread for antihydrogen production,” J. Instrum.
14, P05009 (2019).
L. C. Tao, Y. Ichikawa, C. X. Yuan, Y. Ishibashi, A. Takamine, A. Gladkov, T. Fujita, K. Asahi, T. Egami, C. Funayama, K. Imamura,
J. L. Lou, T. Kawaguchi, S. Kojima, T. Nishizaka, T. Sato, D. Tominaga, X. F. Yang, H. Yamazaki, Y. L. Ye, H. Ueno, Y. Yanagisawa,
and K. Yoshida, “Negative parity states in 39 Cl configured by crossing major shell orbits,” Chin. Phys. Lett. 36, 062101-1–4 (2019).
D. S. Ahn, N. Fukuda, H. Geissel, N. Inabe, N. Iwasa, T. Kubo, K. Kusaka, D. J. Morrissey, D. Murai, T. Nakamura, M. Ohtake, H. Otsu,
H. Sato, B. M. Sherrill, Y. Shimizu, H. Suzuki, H. Takeda, O. B. Tarasov, H. Ueno, Y. Yanagisawa, and K. Yoshida, “Location of theneutron dripline at fluorine and neon,” Phys. Rev. Lett. 123, 212501-1–6 (2019). [Featured in Physics] [Editors’ Suggestion]
S. Tsutsui, M. Mizumaki, and Y. Kobayashi, “Electronic and atomic dynamics in Sm and Eu cage-structured intermetallics,” Hyperfine
Interact. 240, 84-1–16 (2019).
T. Funabashi, Y. Kobayashi, and Y. Yamada, “Metastable iron carbide thin films produced by pulsed laser deposition of iron in methane
atmosphere,” Hyperfine Interact. 240, 121-1–8 (2019).
F. Boulay, G. S. Simpson, Y. Ichikawa, S. Kisyov, D. Bucurescu, A. Takamine, D. S. Ahn, K. Asahi, H. Baba, D. L. Balabanski,
T. Egami, T. Fujita, N. Fukuda, C. Funayama, T. Furukawa, G. Georgiev, A. Gladkov, M. Hass, K. Imamura, N. Inabe, Y. Ishibashi,
T. Kawaguchi, T. Kawamura, W. Kim, Y. Kobayashi, S. Kojima, A. Kusoglu, R. Lozeva, S. Momiyama, I. Mukul, M. Niikura, H. Nishibata, T. Nishizaka, A. Odahara, Y. Ohtomo, D. Ralet, T. Sato, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, L. C. Tao, Y. Togano,
D. Tominaga, H. Ueno, H. Yamazaki, X. F. Yang, and J. M. Daugas, “g-Factor of the 99 Zr (7/2+ ) isomer: Monopole evolution in shapecoexisting region,” Phys. Rev. Lett. 124, 112501-1–6 (2020).
K. Hamazaki, Y. Kobayashi, and Y. Yamada, “Iron nitride films produced by arc deposition of iron in a nitrogen atmosphere,” Hyperfine
Interact. 241, 4-1–10 (2020).
Y. Yamada, Y. Sato, Y. Kobayashi, T. Ando, N. Takahama, K. Some, M. Sato, M. Mihara, M. K. Kubo, W. Sato, J. Miyazaki, T. Nagatomo,
J. Kobayashi, A. Okazawa, S. Sato, and A. Kitagawa, “In-beam Mössbauer spectra for 57 Mn implanted sulfur hexafluoride,” Hyperfine
Interact. 241, 15-1–15 (2020).
T. Otsuka, Y. Tsunoda, T. Abe, N. Shimizu, and P. Van Duppen, “Underlying structure of collective bands and self-organization in quantum
systems,” Phys. Rev. Lett. 123, 222502 (2019).
S. Sels, T. Day Goodacre, B. A. Marsh, A. Pastore, W. Ryssens, Y. Tsunoda, N. Althubiti, B. Andel, A. N. Andreyev, D. Atanasov,
A. E. Barzakh, M. Bender, J. Billowes, K. Blaum, T. E. Cocolios, J. G. Cubiss, J. Dobaczewski, G. J. Farooq-Smith, D. V. Fedorov,
V. N. Fedosseev, K. T. Flanagan, L. P. Gaﬀney, L. Ghys, P.-H. Heenen, M. Huyse, S. Kreim, D. Lunney, K. M. Lynch, V. Manea,
Y. Martinez Palenzuela, T. M. Medonca, P. L. Molkanov, T. Otsuka, J. P. Ramos, R. E. Rossel, S. Rothe, L. Schweikhard, M. D. Seliverstov, P. Spagnoletti, C. Van Beveren, P. Van Duppen, M. Veinhard, E. Verstraelen, A. Welker, K. Wendt, F. Wienholtz, R. N. Wolf, andA. Zadvornaya, “Shape staggering of mid-shell mercury isotopes from in-source laser spectroscopy compared with density functional
theory and Monte Carlo shell model calculations,” Phys. Rev. C 99, 044306 (2019).
F. Flavigny, J. Elseviers, A. N. Andreyev, C. Bauer, V. Bildstein, A. Blazhev, B. A. Brown, H. De Witte, J. Diriken, V. N. Fedosseev,
S. Franchoo, R. Gernhäuser, M. Huyse, S. Ilieva, S. Klupp, Th. Kröll, R. Lutter, B. A. Marsh, D. Mücher, K. Nowak, T. Otsuka,
J. Pakarinen, N. Patronis, R. Raabe, F. Recchia, P. Reiter, T. Roger, S. Sambi, M. Seidlitz, M. D. Seliverstov, B. Siebeck, Y. Tsunoda,
P. Van Duppen, M. Vermeulen, M. Von Schmid, D. Voulot, N. Warr, F. Wenander, and K. Wimmer, “Microscopic structure of coexisting0+ states in 68 Ni probed via two-neutron transfer,” Phys. Rev. C 99, 054332 (2019).
L. Xie, X. F. Yang, C. Wraith, C. Babcock, J. Bieroń, J. Billowes, M. L. Bissell, K. Blaum, B. Cheal, L. Filippin, K. T. Flanagan,
R. F. Garcia Ruiz, W. Gins, G. Gaigalas, M. Godefroid, C. Gorges, L. K. Grob, H. Heylen, P. Jönsson, S. Kaufmann, M. Kowalska,
J. Krämer, S. Malbrunot-Ettenauer, R. Neugart, G. Neyens, W. Nörtershäuser, T. Otsuka, J. Papuga, R. Sánchez, Y. Tsunoda, and
D. T. Yordanov, “Nuclear charge radii of 62–80 Zn and their dependence on cross-shell proton excitations,” Phys. Lett. B 797, 134805(2019).
C. Hornung, D. Amanbayev, I. Dedes, G. Kripko-Koncz, I. Miskun, N. Shimizu, S. Ayet San Andrés, J. Bergmann, T. Dickel, J. Dudek,
J. Ebert, H. Geissel, M. Górska, H. Grawe, F. Greiner, E. Haettner, T. Otsuka, W. R. Plaß, S. Purushothaman, A.-K. Rink, C. Scheidenberger, H. Weick, S. Bagchi, A. Blazhev, O. Charviakova, D. Curien, A. Finlay, S. Kaur, W. Lippert, J.-H. Otto, Z. Patyk, S. Pietri,
Y. K. Tanaka, Y. Tsunoda, and J. S. Winfield, “Isomer studies in the vicinity of the doubly-magic nucleus 100 Sn: Observation of a new
low-lying isomeric state in 97 Ag,” Phys. Lett. B 802, 135200 (2019).
T. Otsuka, A. Gade, O. Sorlin, T. Suzuki, and Y. Utsuno, “Evolution of shell structure in exotic nuclei,” Rev. Mod. Phys. 92, 015002(2020).
T. Miyagi, T. Abe, M. Kohno, P. Navratil, R. Okamoto, T. Otsuka, N. Shimizu, and S. R. Stroberg, “Ground-state properties of doubly
magic nuclei from the unitary-model-operator approach with the chiral two- and three-nucleon forces,” Phys. Rev. C 100, 034310- 266 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53(2019).
B. Abromeit, V. Tripathi, H. L. Crawford, S. N. Liddick, Y. Utsuno, P. C. Bender, B. P. Crider, R. Dungan, P. Fallon, K. Kravvaris,
N. Larson, R. S. Lubna, A. O. Macchiavelli, T. Otsuka, C. J. Prokop, A. L. Richard, N. Shimizu, S. L. Tabor, A. Volya, and S. Yoshida,“Beta decay of T z = +11/2 isotopes 37 Al and 39 Si understanding Gamow Teller strength distribution in neutron rich nuclei,” Phys. Rev.
C 100, 014323 (2019).
A. Matta, W. N. Catford, N. A. Orr, J. Henderson, P. Ruotsalainen, G. Hackman, A. B. Garnsworthy, F. Delaunay, R. Wilkinson, G. Lotay,
N. Tsunoda, T. Otsuka, A. J. Knapton, G. C. Ball, N. Bernier, C. Burbadge, A. Chester, D. S. Cross, S. Cruz, C. Aa. Diget, T. Domingo,
T. E. Drake, L. J. Evitts, F. H. Garcia, S. Hallam, E. MacConnachie, M. Moukaddam, D. Muecher, E. Padilla-Rodal, O. Paetkau,
J. Park, J. L. Pore, U. Rizwan, J. Smallcombe, J. K. Smith, K. Starosta, C. E. Svensson, J. Williams, and M. Williams, “Shell evolution
approaching the N = 20 island of inversion: Structure of 29 Mg,” Phys. Rev. C 99, 044320 (2019).
Y. L. Sun, A. Obertelli, P. Doornenbal, C. Barbieri, Y. Chazono, T. Duguet, H. N. Liu, P. Navrátil, F. Nowacki, K. Ogata, T. Otsuka,
F. Raimondi, V. Somà, Y. Utsuno, K. Yoshida, N. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi,
M. L. Cortés, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. Togano, T. Uesaka,
K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gas̆parić, R. -B. Gerst, J. Gibelin, K. I. Hahn,
D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura,
S. Y. Park, D. Rossi, E. Sahin, D. Sohler, P. -A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner,
X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “Restoration of the natural E(1/2+1 ) − E(3/2+1 ) energy splitting in odd-k
isotopes towards N = 40,” Phys. Lett. B 802, 135215 (2020).
S. Chen, J. Lee, P. Doornenbal, A. Obertelli, C. Barbieri, Y. Chazono, P. Navrátil, K. Ogata, T. Otsuka, F. Raimondi, V. Somà, Y. Utsuno,
K. Yoshida, H. Baba, F. Browne, D. Calvet, F. Château, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon,
A. Gillibert, C. Hilaire, T. Isobe, J. Kahlbow, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu,
V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer,
K. Yoneda, N. Achouri, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gas̆parić, R.-B. Gerst, J. Gibelin, K. I. Hahn,
D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park,D. Rossi, E. Sahin, D. Sohler, P.-A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu,
H. Yamada, D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “Quasifree neutron knockout from corroborates arising neutron magic
number,” Phys. Rev. Lett. 123, 142501 (2020).
F. Diel, Y. Fujita, H. Fujita, F. Cappuzzello, E. Ganioğlu, E.-W. Grewe, T. Hashimoto, K. Hatanaka, M. Honma, T. Itoh, J. Jolie,
B. Liu, T. Otsuka, K. Takahisa, G. Susoy, B. Rubio, and A. Tamii, “High-resolution study of the Gamow-Teller (GT-) strength in
the 60 Zn(3 He, t)64 Ge reaction,” Phys. Rev. C 99, 054322 (2019).

[Review article]
Y. Ichikawa, “Nuclear shell evolution with shape deformation—Structure of exotic nuclei investigated by the magnetic moment—ʢʮม‫ܗ‬͠ͳ͕Β֪ਐԽ—࣓‫ؾ‬ϞʔϝϯτͰ୳ΔΤΩκνοΫ֩ͷʰத਎ʱʯʣ,” Isotope News 765, 26–29 (2019).

Presentations[International conferences/workshops]
H. Ueno (invited), “Nuclear-physics research based on RI spin orientation technique,” XXXVI Mazurian Lakes Conference on Physics,
Piaski, Poland, September 1–7, 2019.
A. Takamine (invited), “Recent progress in the development of gas cells, SHE results combining GARIS with GASCELL+MRTOF,”
Expert Meeting on Next-Generation Fragment Separators 2019, Darmstadt, Germany, September 30–October 3, 2019.
Y. Ichikawa (invited), “Magnetic-moment measurement of exotic nuclei using spin-oriented RI beams at RIBF,” 14th Asia-Pacific Physics
Conference (APPC 2019), Sarawak, Malaysia, November 17–22, 2019.
T. Otsuka (invited), “Self-organization of quantum systems and the structure of heavy nuclei,” Workshop Physics between lead anduranium: In preparation of new experimental campaigns at ISOLDE, Leuven, Bergium, April 16–18, 2019.
T. Otsuka (invited), “Alpha clustering in nuclei and the shell model,” Theoretical Nuclear Physics in Padova: A Meeting in Honor ofProf. Andrea Vitturi, Padova, Italy, May 20–21 2019.
T. Otsuka (invited), “Self-organization in nuclear structure and its impact to heavy nuclei—A challenge to Bohr-Mottelson’s picture and afuture prospect—,” LXIX International Conference on Nuclear Spectroscopy and Nuclear Structure “Fundamental Problems of Nuclear
Physics, Nuclei at Borders of Nucleon Stability, High Technologies,” (Nucleus-2019) , Dubna, Russia, July 1–5, 2019.
T. Otsuka (invited), “Nuclear matrix elements with advanced shell model methods,” Workshop on Progress and Challenges in Neutrinoless
Double Beta Decay, Trento, Italy, July 15–19, 2019.
T. Otsuka (invited), “Ab initio studies on the dripiline of the Island-of-Inversion nuclei,” Workshop on Ab initio Nuclear Theory fromBreakthroughs to Applications, Guildford, UK, July 24–26, 2019.
T. Otsuka (oral), “Self-organization in atomic nuclei and nuclear collectivity,” 27th International Nuclear Physics Conference (INPC2019), Glasgow, UK, July 29–August 2, 2019.
T. Otsuka (invited), “Precision nuclear structure via the Monte-Carlo shell model,” ESNT Workshop Laser Spectroscopy as a Tool for
Nuclear Theories, Saclay, France, October 7–11, 2019.
T. Otsuka (invited), “Evolution of shape and shell of atomic nuclei and the self-organization,” 2XVII International Meeting on “Selected
topics in nuclear and atomic physics,” Fiera di Primiero, Italy, September 30–October 4, 2019.
T. Otsuka (invited), “Olaf gets into shapes,” Symposium on “Particles, photons, and fields: Messengers of violent events from the nucleus,- 267 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

through the sky, to the cosmos,” Groningen, the Netherlands, November 21, 2019.
T. Otsuka (invited), “Self-organization of quantum systems and nuclear collectivity,” International Symposium on Clustering as a Window
on the Hierarchical Structure of Quantum Systems (CLUSHIQ2020), Beppu, Japan, January 23–24, 2020.
T. Otsuka (invited), “Self-organization in nuclear collective bands,” Fifth Topical Workshops on Modern Aspects of Nuclear Structure,
Bormio, Italy, February 4–9, 2020.
T. Otsuka (invited), “Nuclear matrix elements of neutrinoless double beta decay calculated by Monte Carlo shell model for 76 Ge and136
Xe,” International Conference on Neutrino and Nuclear Physics 2020 (CNNP2020), Cape Town, South Africa, February 24–28,
2020.
T. Otsuka (invited), “Structure of F-Ne-Na-Mg isotopes and new mechanism of driplines,” Workshop on Progress in Ab Initio Techniquesin Nuclear Physics, Vancouver, Canada, March 3–6, 2020.

[Domestic conferences/workshops]ࢢ઒༤Ұ, ʮ‫ىྭ֩ࢠݪ‬ঢ়ଶͷ࣓‫ؾ‬Ϟʔϝϯτଌఆʯ, 2019 ೥౓ʮ෺࣭֊૚‫ݪ‬ཧ‫ڀݚ‬ʯˍʮϔςϩք໘‫ڀݚ‬ʯ߹ಉय़߹॓, ‫఼ޚ‬৔,2019 ೥ 5 ݄ 10–11 ೔.
্໺लथ, “Highly Spin-polarized RI beams and the application to nuclear and condensed-matter physics ,” ৽ֶज़ྖҬʮӉ஦‫؍‬ଌ‫ݕ‬ग़‫ࢠྔͱث‬ϏʔϜͷग़ձ͍ɻ ৽ͨͳԠ༻΁ͷՍ͚‫ڮ‬ɻʯୈ 1 ճྖҬશମձٞ, ౦‫ژ‬େֶ Kavli IPMU, ദࢢ, 2019 ೥ 7 ݄ 15–16 ೔.
ߴๆѪࢠ, “Development of an RF ion guide gas cell for universal ultra slow RI beams,” ৽ֶज़ྖҬʮӉ஦‫؍‬ଌ‫ݕ‬ग़‫ࢠྔͱث‬ϏʔϜͷग़ձ͍ɻ৽ͨͳԠ༻΁ͷՍ͚‫ڮ‬ɻʯ, ୈ 1 ճྖҬશମձٞ, ౦‫ژ‬େֶ Kavli IPMU, ദ, 2019 ೥ 7 ݄ 15–16 ೔.
ࠓҪ߁‫و‬, ౻ࢬ྄, ২஛ஐ, ࡫ඌొ, ٢ଜଠ඙, ٢ଜߒ࢘, ٢‫ݟ‬জ༸, ‫ٶ‬ຊ༞थ, ૿ా޹඙, ‫ݪ‬ल໌, ࠓଜ‫ܛ‬, ্֞֎मҰ, த઒޹ल, ۚҪอ೭, ࢢ઒༤Ұ, ௕༑ܼ, ຊా༸հ, ࡔ্࿨೭, ʮྔࢠΠΦϯϏʔϜʢQIB) ෼ޫʹ޲͚ͨ Yb υʔϓϑΝΠόʔΛ༻͍ͨ 987 nm ޫͷ૿෯ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ‫ذ‬ෞେֶ༄‫ށ‬Ωϟϯύε, ‫ذ‬ෞ, 2019 ೥ 9 ݄ 10–13 ೔.
ࠓҪ৳໌, ಊԂণഢ, ಓਖ਼৽Ұ࿠, ୸‫ה‬૱೭, େా৾ี, J. W. Hwang, ‫ؠ‬ຊͪͻΖ, ઒੉ᰌҰ࿠, ઒ా‫ܟ‬ଠ, ๺ଜಙོ, ૿ԬᠳҰ࿕, த໺‫ܟ‬ଠ, P. Schrock, ླ໦େհ, ֯ాཧ‫ࢠܙ‬, K. Wimmer, for ImPACT17-02-02 collaboration, ʮ‫ٯ‬ӡಈֶ 79 Se(d, p) ൓ԠʹΑΔதੑࢠ
ั֫൓Ԡஅ໘ੵͷධՁʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶখന઒Ωϟϯύε, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
઒ా‫ܟ‬ଠ, େా৾ี, ಊԂণഢ, મኍेࡾ, ‫ؠ‬ຊͪͻΖ, ๺ଜಙོ, ञҪӳߦ, ࡫໺‫لڡ‬, ૿ԬᠳҰ࿕, ಓਖ਼৽Ұ࿠, ԣࢁྠ, ໼޲‫ݠ‬ଠ࿠,
Laszlo STUHL, ࡔ‫ོ࣏ޱ‬, ‫ాݪ‬஌໵, ࣉౢ஌, ੢ാᔨ‫ر‬, ֯ాཧ‫ࢠܙ‬, ࠓҪ৳໌, Ningtao Zhang, Jongwon Hwang, ԕ౻ོ࢙, ʮೖࣹ֩ഁࡅ൓ԠʹΑΔ 52 Fe पล֩ͷߴεϐϯΞΠιϚʔͷੜ੒ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶখന઒Ωϟϯύε, ࢁ‫ܗ‬,2019 ೥ 9 ݄ 17–20 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑ଠ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnik, ʮMRTOF-MS Λ༻͍ͨ 207 Ra ͷਫ਼ີ࣭ྔ—่յಛੑଌ
ఆʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶখന઒Ωϟϯύε, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
Ӊ౎໺য়, ࢢ઒ོහ, ਗ਼ਫଇ޹, େ௩޹࣏, ʮ42 Ca ʹ͓͚Δඇ࣠ରশ௒ม‫ܗ‬ঢ়ଶͱଟॏม‫ڞܗ‬ଘʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶখന઒Ωϟϯύε, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
֯ా༎հ, େ௩޹࣏, ਗ਼ਫଇ޹, ʮϞϯςΧϧϩ֪໛‫ʹܕ‬ΑΔ Sm ಉҐମͷ‫ܗ‬ঢ়มԽͷ‫ڀݚ‬ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶখന઒Ωϟϯύε, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
Ѩ෦‫ڤ‬, P. Maris, େ௩޹࣏, ਗ਼ਫଇ޹, ֯ా༎հ, Ӊ౎໺য়, J. P. Vary, ٢ా‫ږ‬, ʮϞϯςΧϧϩ֪໛‫ʹܕ‬ΑΔୈҰ‫ݪ‬ཧ‫͔ࢉܭ‬ΒͷΞϧϑΝΫϥελʔߏ଄ͷ‫ڀݚ‬ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶখന઒Ωϟϯύε, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
্໺लथ, ʮ֩੔ྻ RI ϏʔϜΛ༻͍ͨ β-NMR ଌఆ๏ʯ, ৽ֶज़ྖҬʮΫϥελʔ֊૚ʯ&ʮྔࢠϏʔϜԠ༻ʯ߹ಉ‫ݕ‬ग़‫ث‬ϫʔΫγϣοϓ, ౦๺େֶ੨༿ࢁΩϟϯύε, ઋ୆, 2019 ೥ 9 ݄ 20–21 ೔.
େ௩޹࣏ʢট଴ߨԋʣ, ʮ‫֩ࢠݪ‬෺ཧͷύϥμΠϜγϑτͱ‫ژ‬ίϯϐϡʔλʯ, ‫ڀݚ‬ձ γϛϡϨʔγϣϯʹΑΔӉ஦ͷ‫ج‬ຊ๏ଇͱਐ
Խͷղ໌ʹ޲͚ͯ , ‫౎ژ‬, 2019 ೥ 12 ݄ 16–19 ೔.
খᖒ௚໵, ௕ᖛ߂‫ق‬, ૣਫ༑༸, தଜ‫ܓ‬༎, খߴ߁র, ాத߳௡ੜ, େ௩ະདྷ, খ৿༗‫ࢠر‬, ࢢ઒༤Ұ, Ӌ৔޺ޫ, ্໺लथ, ञ‫ݟ‬ହ‫׮‬,ʮϑϥϯγ΢Ϝ‫ࢠݪ‬ͷి‫ؾ‬૒‫ࢠۃ‬ೳ཰୳ࡧͷͨΊͷද໘ి཭ΠΦϯ‫ݯ‬ͷ։ൃʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰ʢ໊‫ݹ‬԰େֶ‫ݱ‬஍։࠵தࢭʣ, 2020 ೥ 3 ݄ 16–19 ೔.
ԣਢլจ࠸, ߴๆѪࢠ, ాౡඒయ, Ԭ໺ହල, ࠤʑ໦༔ี, ઙՏ୓ޫ, ൧ଜल‫ل‬, ࿨ాಓ࣏, H. A. Schuessler, দඌ༝լར, ্໺लथ, લా͸Δ͔, ʮίϦχΞϨʔβʔ෼ޫΛ࢖ͬͨ Zr ಉҐମͷ֩ߏ଄‫͚ͨ޲ʹڀݚ‬Ϩʔβʔޫ‫ݯ‬։ൃʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ,໊‫ݹ‬԰ʢ໊‫ݹ‬԰େֶ‫ݱ‬஍։࠵தࢭʣ, 2020 ೥ 3 ݄ 16–19 ೔.
੢ଜণً, ࠓଜ‫ܛ‬, ߴๆѪࢠ, ཐྑ݈ଠ, Aleksey Gladkov, ஛಺༝ҥՖ, ౔‫ྤࡾډ‬, ࢁຊঊ, ాౡඒయ, ઙՏ୓ޫ, ࠤʑ໦༔ี, ౔ҪҰา,઒ా‫ܟ‬ଠ, ੢ാᔨ‫ر‬, ࢢ઒༤Ұ, ্໺लथ, দඌ༝լར, ʮӷମ஠ૉ‫ڥ؀‬Լʹ͓͚Δߴ଎ Rb ΠΦϯϏʔϜͷఀࢭҐஔ੍‫ޚ‬ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰ʢ໊‫ݹ‬԰େֶ‫ݱ‬஍։࠵தࢭʣ, 2020 ೥ 3 ݄ 16–19 ೔.
ཐྑ݈ଠ, ࠓଜ‫ܛ‬, ߴๆѪࢠ, ੢ଜণً, Aleksey Gladkov, ஛಺༝ҥՖ, ౔‫ྤࡾډ‬, ࢁຊঊ, ాౡඒయ, ઙՏ୓ޫ, ࠤʑ໦༔ี, ౔ҪҰา,઒ా‫ܟ‬ଠ, ੢ാᔨ‫ر‬, ࢢ઒༤Ұ, ্໺लथ, দඌ༝լར, ʮ֩Ϟʔϝϯτଌఆ๏։ൃͷͨΊͷޫֶ༻ΫϥΠΦελοτʹ͓͚Δ Rb
ͷऩྔଌఆʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰ʢ໊‫ݹ‬԰େֶ‫ݱ‬஍։࠵தࢭʣ, 2020 ೥ 3 ݄ 16–19 ೔.

Press releases“Zirconium isotopes are suddenly deformed even in the excited stateʢʮδϧίχ΢ϜಉҐମ͸ྭ‫ى‬ঢ়ଶͰ΋ಥવม‫͢ܗ‬Δʯʣ,” press
release from RIKEN, March 17, 2020.
RIKEN HP: https://www.riken.jp/press/2020/20200317_2/index.html .
“Basic principles of nuclear shape and self-organization in quantum systems ʢʮ‫֩ࢠݪ‬ͷ‫ܗ‬ͷ‫ج‬ຊ‫ݪ‬ཧͱྔࢠ‫Ͱܥ‬ͷࣗ‫ݾ‬૊৫Խʯʣ,”joint press-release from the University of Tokyo and RIKEN, November 26, 2019.
The Univ. of Tokyo HP: https://www.s.u-tokyo.ac.jp/ja/press/2019/6629/ .
RIKEN HP: https://www.riken.jp/press/2019/20191126_1/index.html .

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53“Research group lead by RIKEN and the University of Tokyo succeeded in measuring excited-state nuclear magnetic moment of a neutronrich copper isotope ʢʮཧ‫ͱݚ‬౦େͳͲ, தੑࢠա৒ͳಔಉҐମ‫֩ࢠݪ‬ͷྭ‫ى‬ঢ়ଶͷ࣓‫ؾ‬Ϟʔϝϯτଌఆʹ੒ޭʯʣ,” Nikkei Shinbun
Newspaper Online, January 30, 2019.
“New structural aspects of copper isotopes unveiled through the nuclear magnetic moment—Successful measurement by maximizing spinalignment of the RI beam—ʢʮ࣓‫ؾ‬Ϟʔϝϯτ͔Β෼͔ΔಔಉҐମͷ৽ͨͳ࢟—‫Ͱ·ݶۃ‬εϐϯ੔ྻ౓ΛߴΊͨ RI ϏʔϜΛ‫ۦ‬࢖ͯ͠ଌఆʹ੒ޭ—ʯʣ,” joint press-release from RIKEN and the University of Tokyo, January 30, 2019.
RIKEN HP: https://www.riken.jp/press/2019/20190130_2/ .
The Univ. of Tokyo HP: https://www.s.u-tokyo.ac.jp/ja/info/6251/ .
JICFuS HP: https://www.jicfus.jp/jp/190130pressrelease/ .

Outreach activities
H. Ueno, Special Exhibition of the International Year of the Periodic Table 2019ʢࠃࡍप‫ظ‬ද೥ಛผల 2019ʮཧԽֶ‫ॴڀݚ‬ͷχϗχ΢Ϝ໛‫ܕ‬Λͭ͘Ζ͏ʯʣ, Ehime Prefectural Science Museum, January 18–19, 2020.
ʮ‫֩ࢠݪ‬Λั·͑ͯޫͰ
A. Takamine, Interactive Event “RIKEN DAY: Let’s talk with researchers!” ʢཧ‫ ݚ‬DAYɿ‫ͱऀڀݚ‬࿩ͦ͏ʂΈΔʯʣ, Tokyo Science Museum, December 15, 2019.
H. Ueno, RIKEN Osaka Campus Open Day 2019, Suita, November 23, 2019.
H. Ueno, Kagakudo 100 Books 2019 Selection CommitteeʢՊֶಓ 100 ࡭ 2019 બॻҕһձ).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research DivisionHigh Energy Astrophysics Laborarory
1. Abstract

In the immediate aftermath of the Big Bang, the beginning of our universe, only hydrogen and helium existed. However, nuclear
fusion in the interior of stars and the explosion of supernovae in the universe over 13.8 billion years led to the evolution of a world
brimming with the many diﬀerent elements we have today. By using scientific satellites or balloons to observe X-rays and gamma-rays
emitted from celestial objects, we are observing the synthesis of the elements at their actual source. Our goal is to comprehensively
elucidate the scenarios for the formation of the elements in the universe, together with our research on sub-atomic physics through theuse of an accelerator.

2. Major Research Subjects(1) Nucleosynthesis in stars, supernovae, and neutron star mergers(2) Plasma and vacuum in extremely strong magnetism and gravity(3) Research and development of innovative X-ray and gamma-ray detectors

3. Summary of Research Activity

High Energy Astrophysics Laboratory started in April 2010. The goal of our research is to reveal the mechanism of nucleosynthesis and the evolution of elements in the universe, and to observe/discover exotic physical phenomena in extremely strong magnetic
and/or gravitational fields. We have observed supernova remnants, strongly magnetized neutron stars, pulsars, black holes and galaxies
with X-ray astronomical satellites, balloons and ground-based telescopes.
(1) Nucleosynthesis in the universe(1-1) XRISM
We have contributed to the XRISM (X-ray imaging and spectroscopy mission) mission for the launch in 2022. XRISM is therecovery mission of the ASTRO-H/Hitomi satellite, which was launched in February 2016 but lost by an accident one month after thelaunch. Hitomi carried four X-ray and gamma-ray detectors covering the 0.3–600 keV energy range. We, in collaboration with JAXA
(Japan Aerospace Exploration Agency), Tokyo Metropolitan University, Kanazawa University, Saitama University, NASA/GSFC etc.,
contributed to the soft X-ray spectrometer (SXS), which achieves unprecedented energy resolution (<7 eV) in the 0.3–12 keV energy
band with a low temperature micro calorimeter. We hoped to use SXS to discover many previously-unknown elemental lines in theuniverse and to measure the abundance of these elements, but this was not possible with Hitomi. The XRISM satellite carries almost
identical X-ray detectors as the Hitomi satellite, and is expected to carry out scientific observations that were not done with the Hitomi
mission.
(1-2) MAXI
From April 2018, High Energy Astrophysics Laboratory hosts MAXI (Monitor of All-sky X-ray Image) onboard International
Space Station (ISS), which was attached on ISS in 2009. MAXI is a RIKEN-lead project collaborating with JAXA and other universities. Since MAXI scans X-ray all-sky in 90 minutes, many transient objects including neutron star or blackhole binaries are found. Allof the data are going to public soon after they are taken, and almost all of the groups in high-energy phenomena rely on the MAXI data.
In 2018, we issued 34 alerts as ATEL (Astronomer’s Telegram) and 5 new blackhole candidates were found. To detect counterpartsof neutron star merger events (i.e. gravitational wave events), we have prepared an automatic searching system and keep watching
all-sky.
(1-3) Astrophysical Data Analysis
In parallel with the mission development/operations, we performed data analysis.
• We proved that the abundance ratios of the iron-peak elements in the Perseus cluster were consistent with the solar abundance. In
previous studies, overabundance of Cr, Mn, and Ni are reported, but Hitomi’s high spectroscopic data denied the overabundance.
The inter-galactic medium of the nearby cluster has similar abundance pattern of our galaxy.
• We have detected a mysterious hump in the spectrum of the neutronstar low-mass X-ray binary, Aquila X-1. The hump can beinterpreted as a recombination-edge of heavy elements (Cd) which were possibly produced by rp-process in X-ray bursts on theneutron star surface.
(2) Extremely strong magnetism and gravity
We have contributed to the NASA’s world-first X-ray polarimeter mission IXPE (Imaging X-ray Polarimeter Explorer). HighEnergy Astrophysics Laboratory is responsible for providing the gas electron multipliers (GEMs) to the IXPE mission: the GEM is a
key device of the X-ray polarimeter and produced based on our patent for space use. The IXPE satellite will be launched in the second
half of 2021. We have already provided the flight qualified GEMs to the project in FY2018, and have contributed to the detector
calibrations in FY2019.
By using the IXPE mission, we aim to proof the strong magnetism of Magnetars, which are one of the species of neutron stars
which have ultra-strong magnetic field B > 1011 T. In such ultra-strong magnetic field, higher-order diagrams, O(eB/m2 ), O(eB/m2 )2
etc., never eliminated in the QED perturbation theory. As the results, we observe newly-emerging phenomenon such as vacuum
polarization, vacuum birefringence, etc. If such exotic phenomena are detected, we sure that Magnetars have really ultra-strong- 270 -

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magnetic field.
(3) Innovative X-ray and gamma-ray detectors
In collaboration with NASA Goddard Space Flight Center, we have developed and tested a hard X-ray polarimeter with a Time
Projection Chamber technique. This TPC polarimeter is one of candidates of the future satellite XPP (X-ray polarimeter Probe
mission) planned with an international consortium.
As an successor of the MAXI mission, we are also verifying the principle of a new concept, multiplexing lobster-eye (MuLE)
optics, to monitor the entire sky with a wide field-of-view for detecting and immediate reporting transient objects such as a neutronstar merger.

Members
Group Director
Toru TAMAGAWA
Research/Technical Scientist
Tatehiro MIHARA (Senior Research Scientist)
Contract Researcher
Takao KITAGUCHI
Visiting Researcher
Asami HAYATO (JSPS Fellow)
Visiting Scientists
Aya BAMBA (Univ. of Tokyo)
Teruaki ENOTO (Kyoto Univ.)
Naohisa INADA (NIT, Nara College)
Satoru KATSUDA (Saitama Univ.)
Tomoki KIMURA (Tohoku Univ.)
Motohide KOKUBUN (ISAS/JAXA)
Toru MISAWA (Shinshu Univ.)
Ikuyuki MITSUISHI (Nagoya Univ.)
Yujin NAKAGAWA (JAMSTEC)
Toshio NAKANO (JTEC Corporation)

Hirofumi NODA (Osaka Univ.)
Hirokazu ODAKA (Univ. of Tokyo)
Yuki OKURA (NAOJ/Nat’l Inst. of Natural Sci.)
Rohta TAKAHASHI (NIT, Tomakomai College)
Yoko TAKEUCHI (TIRI)
Yukikatsu TERADA (Saitama Univ.)
Harufumi TSUCHIYA (JAEA)
Masaki WAKABAYASHI (Jakulin Commercial Company LC)
Shin’ya YAMADA (Tokyo Metoropolitan University)

Student Trainees
Miho OKUBO (Tokyo University of Science)
Tomoshi TAKEDA (Tokyo University of Science)
Marina TSUTSUMI (Tokyo University of Science)

Keisuke UCHIYAMA (Tokyo University of Science)
Yuto YOSHIDA (Tokyo University of Science)
Yuuki WADA (Univ. of Tokyo)

List of Publications & Presentations
Publications[Original papers]
T. Ebisuzaki, J. Katori, J. Makino, A. Noda, H. Shinkai, and T. Tamagawa, “INO: Interplanetary network of optical lattice clocks,” Int. J.
Mod. Phys. D 29, id.1940002 (2020).
S. Oda, M. Shidatsu, S. Nakahira, T. Tamagawa, Y. Moritani, R. Itoh, Y. Ueda, H. Negoro, K. Makishima, N. Kawai, and T. Mihara,“X-ray and optical observations of the black hole candidate MAXI J1828-249,” Publ. Astron. Soc. Jpn. 71, id.108 (2019).
T. Kitaguchi, K. Black, T. Enoto, A. Hayato, J. Hill, W. Iwakiri, P. Kaaret, T. Mizuno, and T. Tamagawa, “A convolutional neural network
approach for reconstructing polarization information of photoelectric X-ray polarimeters,” Nucl. Instrum. Methods Phys. Res. A 942,
id.162389 (2019).
M. Kubota, T. Tamagawa, K. Makishima, T. Nakano, W. Iwakiri, M Sugizaki, and K. Ono, “An enigmatic hump around 30 keV in Suzaku
spectra of Aquila X-1 in the hard state,” Publ. Astron. Soc. Jpn. 71, id.33 (2019).
C. Hu, T. Mihara, M. Sugizaki, Y. Ueda, and T. Enoto, “Monitoring the superorbital period variation and spin period evolution of SMC
X-1,” Astrophys. J. 885, id.123 (2019).
E. Gotthelf, J. Halpern, J. Alford, T. Mihara, H. Negoro, N. Kawai, S. Dai, M. Lower, S. Johnston, M. Bailes, S. Oslowski, F. Camilo,
H. Miyasaka, and K. Madsen, “The 2018 x-ray and radio outburst of magnetar XTE J1810-197,” Astrophys. J. Lett. 874, id.L25 (2019).
Q. Abarr, M. Baring, B. Beheshtipour, M. Beilicke, G. de Geronimo, P. Dowkontt, M. Errando, V. Guarino, N. Iyer, F. Kislat, M. Kiss,
T. Kitaguchi, H. Krawczynski, J. Lanzi, S. Li, L. Lisalda, T. Okajima, M. Pearce, L. Press, B. Rauch, D. Stuchlik, H. Takahashi, J. Tang,
N. Uchida, A. West, P. Jenke, H. Krimm, A. Lien, C. Malacaria, J. Miller, and C. Wilson-Hodge, “Observations of a GX 301-2 apastronflare with the x-calibur hard x-ray polarimeter supported by NICER, the swift XRT and BAT, and fermi GBM,” Astrophys. J. 891, id.70(2020).
M. Ohno, et al., “Event-selection technique for the multi-layer Si -CdTe Compton camera onboard Hitomi,” Nucl. Instrum. Methods Phys.
Res. A 924, 327–331 (2019).

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Presentations[International conferences/workshops]
Y. Takeuchi (Oral), “Development and properties of 100 mm-square size LTCC-GEM,” The 6th International Conference on Micro Pattern
Gaseous Detectors (MPGD19), La Rochelle, France, May 5–10, 2019.
T. Kitaguchi (Poster), “A machine learning approach for reconstructing X-ray polarization information acquired with micro-pattern gas
polarimeters,” The 6th International Conference on Micro Pattern Gaseous Detectors (MPGD19), La Rochelle, France, May 5–10,
2019.
K. Uchiyama (Poster), “Irradiation test with heavy ions of fine-pitch LCP-GEMs for the IXPE satellite mission,” The 6th International
Conference on Micro Pattern Gaseous Detectors (MPGD19), La Rochelle, France, May 5–10, 2019.

[Domestic conferences/workshops]ࡾ‫ޱ( ߂ݐݪ‬಄ൃද), ʮશఱ X ઢ‫૷ࢹ؂‬ஔ MAXI ͷ 10 ೥ʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
ᜊ౻༾ (‫ޱ‬಄ൃද), ʮখ‫ܕ‬Ӵ੕౥ࡌΛ໨ࢦͨ͠ΨϯϚઢόʔετภޫ౓‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬,2019 ೥ 9 ݄ 17–20 ೔.
ߴ‫ޱ( ॆ߂ڮ‬಄ൃද), ʮߗ X ઢूޫภޫ‫ ܭ‬XL-Calibur ‫ݧ࣮ٿؾ‬ͷ 2021 ೥ϑϥΠτ΁޲͚ͨ४උঢ়‫گ‬ʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
။ᖒ༏ً (‫ޱ‬಄ൃද), ʮCMOS ΠϝʔδϟΛ༻͍ͨ X ઢภޫࡱ૾γεςϜͷ։ൃ IIIʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019
೥ 9 ݄ 17–20 ೔.
‫࢘܊‬मҰ (‫ޱ‬಄ൃද), ʮภޫ X ઢ‫؍‬ଌӴ੕ IXPE ͷਐ௙ঢ়‫ͱگ‬γϛϡϨʔγϣϯ΁ͷऔΓ૊Έʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ,໊‫ݹ‬԰େֶ, ΦϯϥΠϯ։࠵, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
಺ࢁ‫ܚ‬༞ (‫ޱ‬಄ൃද), ʮIXPE Ӵ੕౥ࡌ GEM ͷӉ஦ઢॏΠΦϯ΁ͷ଱ੑࢼ‫ݧ‬ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ΦϯϥΠϯ։࠵, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
य़೔஌໌ (‫ޱ‬಄ൃද), ʮCMOS ΠϝʔδϟΛ༻͍ͨ X ઢภޫࡱ૾γεςϜͷ։ൃ IVʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ΦϯϥΠϯ։࠵, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
‫ۄ‬઒ప (‫ޱ‬಄ൃද), ʮX ઢภޫ‫؍‬ଌӴ੕ IXPE ΁ͷࢀՃ‫ݱ‬ঢ় (5)ʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘
͹, 2020 ೥ 3 ݄ 16–19 ೔.
ࢁ‫ޱ‬༑༸ (‫ޱ‬಄ൃද), ʮX ઢภޫ‫؍‬ଌӴ੕ IXPE ౥ࡌ X ઢ๬ԕ‫༻ڸ‬डಈ‫ܕ‬೤੍‫ޚ‬ૉࢠαʔϚϧγʔϧυͷ։ൃ (6)ʯʯ, ೔ຊఱจֶ
ձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ࢁຊཾ࠸ (‫ޱ‬಄ൃද), ʮγϛϡϨʔγϣϯΛ༻͍ͨ IXPE Ӵ੕ʹΑΔ޿͕ͬͨఱମͷ X ઢภޫղੳख๏ͷ‫ڀݚ‬ʯʯ, ೔ຊఱจֶձ
2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ി಺߁ี (‫ޱ‬಄ൃද), ʮCMOS ΠϝʔδηϯαΛ༻͍ͨߗ X ઢࡱ૾ภޫ‫ܭ‬ͷ։ൃ IIʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ,ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ߴ‫ޱ( ॆ߂ڮ‬಄ൃද), ʮߗ X ઢภޫ‫؍‬ଌ࣮‫ ݧ‬XL-Calibur ‫ٿؾ‬ͷ 2021 ೥ϑϥΠτ΁޲͚ͨ४උঢ়‫گ‬ʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ᖒ໺ୡ࠸ (‫ޱ‬಄ൃද), ʮॏྗ೾‫ ݯ‬X ઢରԠఱମ୳ࠪ‫ܭ‬ը Kanazawa-SAT3 ϑϥΠτϞσϧͷ෼ޫੑೳධՁʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ੴ࡚‫ۍ‬ঘ (‫ޱ‬಄ൃද), ʮX ઢ෼ޫࡱ૾Ӵ੕ XRISM ౥ࡌ Resolve ͷ։ൃͷ‫ݱ‬ঢ় Vʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ࡾ‫ޱ( ߂ݐݪ‬಄ൃද), ʮMAXI/GSC ʹΑΔ ۜՏ‫ܥ‬ϋϩʔͷ BH ࿈੕ MAXI J0637-430 ͷൃ‫ͱݟ‬, 2019 ೥౓‫ޙ‬൒ͷಥൃ‫ݱ‬৅ʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ઙҪ࿨ඒ (‫ޱ‬಄ൃද), ʮதੑࢠ੕ͱͷ௿࣭ྔ X ઢ࿈੕ͷ௕‫ظ‬มಈʹ͍ͭͯ IIʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
ߴౢ૱ (‫ޱ‬಄ൃද), ʮʮ͘͢͟ʯӴ੕ʹΑΔ߱ணதੑࢠ੕ SMC X-1 ͷ޿͕ͬͨమًઢͷղੳͱͦͷ‫ي‬ಓɾ௒‫ي‬ಓҐ૬ґଘੑʯʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ஜ೾େֶ, ΦϯϥΠϯ։࠵, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
‫ۄ‬઒ప (‫ޱ‬಄ൃද), ʮX ઢภޫ‫؍‬ଌӴ੕ IXPE ΁ͷࢀՃ‫ݱ‬ঢ় (4)ʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ, ‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄
11–13 ೔.
ࡾੴҮ೭ (‫ޱ‬಄ൃද), ʮX ઢภޫ‫؍‬ଌӴ੕ IXPE ౥ࡌ X ઢ๬ԕ‫༻ڸ‬डಈ‫ܕ‬೤੍‫ޚ‬ૉࢠαʔϚϧγʔϧυͷ։ൃ (5)ʯ, ೔ຊఱจֶձ
2019 ೥ळ‫ق‬೥ձ, ‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄ 11–13 ೔.
ࢁຊཾ࠸ (‫ޱ‬಄ൃද), ʮγϛϡϨʔγϣϯΛ༻͍ͨ IXPE Ӵ੕ʹΑΔ X ઢภޫղੳख๏ͷ‫ڀݚ‬ʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ,‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄ 11–13 ೔.
๺‫وޱ‬༤ (‫ޱ‬಄ൃද), ʮ‫ػ‬ցֶशΛ༻͍ͨඈ੻ը૾ॲཧʹΑΔޫిࢠ௥੻‫̭ܕ‬ઢภޫ‫ܭ‬ͷ‫্͓޲౓ײ‬Αͼ IXPE Ӵ੕σʔλ΁ͷԠ༻ʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ, ‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄ 11–13 ೔.
ੴ࡚‫ۍ‬ঘ (‫ޱ‬಄ൃද), ʮX ઢ෼ޫࡱ૾Ӵ੕ XRISM ౥ࡌ Resolve ͷ։ൃͷ‫ݱ‬ঢ় IVʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ, ‫۽‬ຊେֶ, ‫۽‬ຊ,2019 ೥ 9 ݄ 11–13 ೔.
খߴ༟࿨ (‫ޱ‬಄ൃද), ʮCMOS ΠϝʔδηϯαΛ༻͍ͨߗ X ઢࡱ૾ภޫ‫ܭ‬ͷ։ൃʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ, ‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄ 11–13 ೔.
େ‫ٱ‬อඒึ (‫ޱ‬಄ൃද), ʮγϯΫϩτϩϯ์ࣹޫΛ༻͍ͨߴΤωϧΪʔ X ઢภޫ‫ܭ‬ͷੑೳධՁʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ,‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄ 11–13 ೔.
ߴ‫ޱ( ॆ߂ڮ‬಄ൃද), ʮߗ̭ઢภޫ‫؍‬ଌ࣮‫ ݧ‬X(L)-Calibur ‫ٿؾ‬ͷ 2018 ೥ͷ‫؍‬ଌ݁Ռͱ 2021 ೥ϑϥΠτ΁޲͚ͨ४උঢ়‫گ‬ʯ, ೔ຊఱจֶձ 2019 ೥ळ‫ق‬೥ձ, ‫۽‬ຊେֶ, ‫۽‬ຊ, 2019 ೥ 9 ݄ 11–13 ೔.

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෢ా๎ࢤ (‫ޱ‬಄ൃද), ʮAPV25/SRS Λར༻ͨ͠ TPC X ઢภޫ‫ܭ‬ͷ։ൃͱภޫ‫؍‬ଌʹ࠷దͳ APV 25 ઃఆͷௐࠪʯ, ϚΠΫϩύλʔϯΨε‫ݕ‬ग़‫ & ث‬ΞΫςΟϒഔ࣭ TPC ߹ಉ‫ڀݚ‬ձ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 12 ݄ 6–7 ೔.
٢ా༐ొɾࠤ౻޺थ (‫ޱ‬಄ൃද), ʮ௒খ‫ܕ‬Ӵ੕౥ࡌ༻ GEM X ઢ‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ϚΠΫϩύλʔϯΨε‫ݕ‬ग़‫ & ث‬ΞΫςΟϒഔ࣭
TPC ߹ಉ‫ڀݚ‬ձ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 12 ݄ 6–7 ೔.
पᅵً (ϙελʔൃද), ʮࡱ૾ૉࢠͷ਺Λେ෯ʹ࡟‫͢ݮ‬ΔଟॏԽϩϒελʔΞΠ X ઢ ޫֶ‫ܥ‬ͷ։ൃ࣮ূʯ, JAXA Ӊ஦Պֶ‫ॴڀݚ‬,૬໛‫ݪ‬, 2020 ೥ 1 ݄ 8–9 ೔.
‫࢘܊‬मҰ (ϙελʔൃද), ʮIXPE Ӵ੕ʹΑΔ޿͕ͬͨఱମͷ‫؍‬ଌγϛϡϨʔγϣϯʯ, JAXA Ӊ஦Պֶ‫ॴڀݚ‬, ૬໛‫ݪ‬, 2020 ೥ 1 ݄
8–9 ೔.
ࡾੴҮ೭ (ϙελʔൃද), ʮX ઢภޫ‫؍‬ଌӴ੕ IXPE ౥ࡌʹ޲͚ͨ๬ԕ‫༻ڸ‬αʔϚϧ γʔϧυͷ։ൃʯ, JAXA Ӊ஦Պֶ‫ॴڀݚ‬, ૬໛‫ݪ‬, 2020 ೥ 1 ݄ 8–9 ೔.
ߴ‫( ॆ߂ڮ‬ϙελʔൃද), ʮߗ X ઢूޫภޫ‫ ܭ‬X(L)-Calibur ‫ݧ࣮ٿؾ‬ͷ 2018 ೥ϑϥΠτͱকདྷ‫ܭ‬ըʯ, JAXA Ӊ஦Պֶ‫ॴڀݚ‬, ૬໛‫ݪ‬, 2020 ೥ 1 ݄ 8–9 ೔.
‫ۄ‬઒ప (ϙελʔൃද), ʮX ઢภޫ‫؍‬ଌӴ੕ IXPEʯ, JAXA Ӊ஦Պֶ‫ॴڀݚ‬, ૬໛‫ݪ‬, 2020 ೥ 1 ݄ 8–9 ೔.
ੴ࡚‫ۍ‬ঘ (ϙελʔൃද), ʮX ઢ෼ޫࡱ૾Ӵ੕ (XRISM) ౥ࡌ Resolve ͷ։ൃঢ়‫گ‬ʯ, JAXA Ӊ஦Պֶ‫ॴڀݚ‬, ૬໛‫ݪ‬, 2020 ೥ 1 ݄
8–9 ೔.

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Nuclear Science and Transmutation Research Division
Superheavy Element Research Group
1. Abstract
The elements with their atomic number Z > 103 are called as trans-actinide or superheavy elements. This group has been studying
the physical and chemical properties of superheavy elements. They must be produced by artificially for the scientific study utilizing
the accelerators in RIBF. Two teams lead the study of the superheavy elements. Superheavy Element Production Team studies various
methods of eﬃcient production of the superheavy elements and their physical and chemical properties. Superheavy Element Device
Development Team develops the main experimental device, i.e., the gas-filled recoil ion separator, GARIS.
The synthesis of elements having atomic numbers over 119 will be attempted with the aim of establishing nuclear synthesis
technology that reaches the “island of stability” where the lifetime of atomic nuclei is expected be prolonged significantly. With theaim of constructing an ultimate nuclear model, maximum utilization will be made of key experimental devices which become fully
operational in order to conduct research for the syntheses of element 119 and 120.

2. Major Research Subjects
Superheavy Element Production Team
(1) Searching for new elements(2) Spectroscopic study of the nucleus of heavy elements(3) Chemistry of superheavy elements(4) Study of a reaction mechanism for fusion process
Superheavy Element Device Development Team
(5) Maintenance of GARIS, GARIS-II and development of new gas-filled recoil ion separator GARIS-III(6) Maintenance and development of detector and DAQ system for GARIS, GARIS-II and GARIS-III(7) Maintenance and development of target system for GARIS, GARIS-II and GARIS-III

3. Summary of Research Activity(1) Searching for new elements
To expand the periodic table of elements and the nuclear chart, we will search for new elements.
(2) Spectroscopic study of the nucleus of heavy elements
Using the high sensitivity system for detecting the heaviest element, we plan to perform a spectroscopic study of nuclei of theheavy elements.
(3) Chemistry of superheavy elements
Study of chemistry of the trans-actinide (superheavy element) has just started world-wide, making it a new frontier in the field ofchemistry. Relativistic eﬀects in chemical property are predicted by many theoretical studies. We will try to develop this new field.
(4) Study of a reaction mechanism for fusion process
Superheavy elements have been produced by complete fusion reaction of two heavy nuclei. However, the reaction mechanism of
the fusion process is still not well understood theoretically. When we design an experiment to synthesize nuclei of the superheavy
elements, we need to determine a beam-target combination and the most appropriate reaction energy. This is when the theory becomes
important. We will try to develop a reaction theory useful in designing an experiment by collaborating with the theorists.
(5) Research Highlight
The discovery of a new element is one of the exciting topics both for nuclear physicists and nuclear chemists. The elements with
their atomic number Z > 103 are called as trans-actinides or superheavy elements. The chemical properties of those elements have notyet been studied in detail. Since those elements do not exist in nature, they must be produced by artificially, by using nuclear reactions
for the study of those elements. Because the production rate of atoms of those elements is extremely small, an eﬃcient production andcollection are key issues of the superheavy research. In our laboratory, we have been trying to produce new elements, studying thephysical and chemical properties of the superheavy elements utilizing the accelerators in RIKEN.
Although the Research Group for Superheavy element has started at April 2013, the Group is a renewal of the Superheay Element
Laboratory started at April 2006, based on a research group which belonged to the RIKEN accelerator research facility (RARF), andhad studied the productions of the heaviest elements. The main experimental apparatus is a gas-filled recoil ion separator GARIS. The
heaviest elements with their atomic numbers, 107 (Bohrium), 108 (Hassium), 109 (Meitnerium), 110 (Darmstadtium), 111 (Roentogenium), and 112 (Copernicium) were discovered as new elements at Helmholtzzentrum für Schwerionenforschung GmbH (GSI),
Germany by using 208 Pb or 209 Bi based complete fusion reactions, so called “cold fusion” reactions. We have made independentconfirmations of the productions of isotopes of 108th, 110th, 111th, and 112th elements by using the same reactions performed at GSI.
After these work, we observed an isotope of the 113th element, 278 113, in July 2004, in April, 2005, and in August 2012. The isotope,
278
113, has both the largest atomic number, (Z = 113) and atomic mass number (A = 278) which have determined experimentally
among the isotopes which have been produced by cold fusion reactions. We could show the world highest sensitivity for production
and detection of the superheavy elements by these observations. Our results that related to 278 113 has been recognized as a discovery- 274 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

of new element by a Joint Working Party of the International Union of Pure and Applied Chemistry (IUPAC) and International Union
of Pure and Applied Physics (IUPAP). Finally, we named the 113th element as “Nihonium.”
We decided to make one more recoil separator GARIS-II, which has an acceptance twice as large as existing GARIS, in order torealize higher sensitivity. The design of GARIS-II has finished in 2008. All fabrication of the separator will be finished at the end of
fiscal year 2008. It has been ready for operation after some commissioning works.
Preparatory work for the study of the chemical properties of the superheavy elements has started by using the gas-jet transportsystem coupled to GARIS. The experiment was quite successful. The background radioactivity of unwanted reaction products has beenhighly suppressed. Without using the recoil separator upstream the gas-jet transport system, large amount of unwanted radioactivity
strongly prevents the unique identification of the event of our interest. This new technique makes clean and clear studies of chemistryof the heaviest elements promising.
The spectroscopic study of the heaviest elements has started by using alpha spectrometry. New isotope, 263 Hs (Z = 108), which
has the smallest atomic mass number ever observed among the Hassium isotopes, had discovered in the study. New spectroscopic
information for 264 Hs and its daughters have obtained also. The spectroscopic study of Rutherfordium isotope 261 Rf (Z = 104) has
done and 1.9-s isomeric state has directly produced for the first time.
Preparatory works for the study of the new superheavy elements with atomic number 119 and 120 have started in 2013. We
measured the reaction products of the 248 Cm (48 Ca, xn)296- x Lv (Z = 116) previously studied by Frelov Laboratory of Nuclear Reaction,
Russia, and GSI. We observed 5 isotopes in total which tentatively assigned to 293 Lv, and 292 Lv.

MemberDirector
Kosuke MORITA

List of Publications & Presentations
Publications[Original papers]
T. Tanaka, K. Morita, K. Morimoto, D. Kaji, H. Haba, R. A. Boll, N. T. Brewer, S. Van Cleve, D. J. Dean, S. Ishizawa, Y. Ito, Y. Komori,K. Nishio, T. Niwase, B. C. Rasco, J. B. Roberto, K. P. Rykaczewski, H. Sakai, D. W. Stracener, and K. Hagino, “Study of quasielastic
barrier distributions as a step towards the synthesis of superheavy elements with hot fusion reactions,” Phys. Rev. Lett. 124, 052502-1–
052502-6 (2020).

Presentations[International conferences/workshops]
K. Morita (invited), “Superheavy element search at RIKEN,” The 4th International Symposium on Superheavy Elements (SHE2019),
Hakone, Japan, December 1–5, 2019.
S. Sakaguchi (oral), “Perspective in the super heavy element research,” Joint Kickoﬀ Meeting of JSPS/NRF/NSFC A3 Foresight Program“Nuclear physics in the 21st century,” Kobe, Japan, December 6–7, 2019.

Awards৿ాߒհ, ʮ113 ൪‫ݩ‬ૉͷൃ‫ʹݟ‬ΑΔ์ࣹԽֶ΁ͷߩ‫ݙ‬ʯ, ୈ 63 ճ೔ຊ์ࣹԽֶ, ໦ଜ৆.

Others৿ాߒհ, ཧԽֶ‫ ॴڀݚ‬Ұൠެ։, ཧԽֶ‫ ॴڀݚ‬കଠ࿠ϗʔϧ, ࿨ޫ, 2019 ೥ 04 ݄ 20 ೔.
৿ాߒհ, ֩ԽֶՆͷֶߍ, ༝෍Ӄ ༝෍τϐΞ, ༝෍, 2019 ೥ 09 ݄ 13 ೔.
৿ాߒհ,ʮ৽‫ݩ‬ૉͷ୳ࡧʯ, ࡨମԽֶ౼࿦ձࢢຽߨ࠲, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2019 ೥ 09 ݄ 21 ೔.
৿ాߒհ,ʮ113 ൪‫ݩ‬ૉͷൃ‫ʹݟ‬ΑΔ์ࣹԽֶ΁ͷߩ‫ݙ‬ʯ, ೔ຊ์ࣹԽֶֶձ, ͍Θ͖, 2019 ೥ 09 ݄ 25 ೔.
৿ాߒհ,ʮαΠΤϯεΧϑΣ in SAGAʯ, ࢈‫ۀ‬࿑ಇ෦ ΋ͷͮ͘Γ࢈‫ۀ‬՝, Պֶ‫ؗ‬, ௗ੘, 2019 ೥ 09 ݄ 28 ೔.
৿ాߒհ,ʮ৽‫ݩ‬ૉͷ୳ࡧʯ, ࡛‫ۄ‬େֶʢཧֶ෦ʣΉͭΊࡇ, ࡛‫ۄ࡛ ۄ‬େֶཧֶ෦, ͍ͨ͞·, 2019 ೥ 11 ݄ 02 ೔.
৿ాߒհ, IYPT ดձࣜ, ౦‫ ژ‬౦‫ژ‬ϓϦϯεϗςϧ, ౦‫ژ‬, 2019 ೥ 12 ݄ 05 ೔.
৿ాߒհ,ʮ৽‫ݩ‬ૉͷ୳ࡧʯ, େ෼‫ؔػڀݚݧࢼݝ‬, େ෼‫ཱݝݝ‬ਤॻ‫ؗ‬, େ෼, 2019 ೥ 11 ݄ 16 ೔.
৿ాߒհ,ʮ෱ҪαΠΤϯεϑΣελʯ, ෱Ҫ‫ڭݝ‬ҭி, ෱Ҫࢢ AOSSA, ෱Ҫ, 2019 ೥ 02 ݄ 11 ೔.
৿ాߒհ,ʮ೔ຊͷ͍͢͝Պֶऀʯ, ே೔খֶੜ৽ฉ, 2019 ೥ 10 ݄ 07 ೔.
৿ాߒհ,ʮ113 ൪ɾ119 ൪‫ݩ‬ૉ΁ͷࢥ͍ʯ, ຖ೔৽ฉ, 2019 ೥ 08 ݄ 22 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Superheavy Element Research Group
Superheavy Element Production Team
1. Abstract

The elements with atomic number Z ≥ 104 are called as trans-actinide or superheavy elements (SHEs). Superheavy Element
Production Team investigates synthesis mechanisms of SHEs, nuclear properties of SHE nuclei, and chemical properties of SHEs
mainly in collaboration with Superheavy Element Devise Development Team and Nuclear Chemistry Research Team of RIKEN
Nishina Center.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Search for new superheavy elements
Decay spectroscopy of the heaviest nuclei
Study of reaction mechanisms for production of the heaviest nuclei
Study of chemical properties of the heaviest elements

Summary of Research Activity(1) Search for new superheavy elements
In November, 2016, the 7th period of the periodic table was completed with the oﬃcial approval of four new elements, nihonium(Nh, atomic number Z = 113), moscovium (Mc, Z = 115), tennessine (Ts, Z = 117), and oganesson (Og, Z = 118) by International
Union of Pure and Applied Chemistry (IUPAC). We have started to search for new elements to expand the chart of the nuclides toward
to the island of stability and the periodic table of the elements toward the 8th period of the periodic table. Since June, 2017, RIKEN
heavy-ion Linear ACcelerator (RILAC) has been shut down for its upgrade until the end of 2019. During this long-term break, tocontinue SHE studies at RIBF, we moved GAs-filled Recoil Ion Separator II (GARIS II) from the irradiation room of RILAC to theE6 room of RIKEN Ring Cyclotron (RRC). In December 2017, the RRC + GARIS II setup became ready for SHE studies. We first
conducted the commissioning of the RRC + GARIS II setup in the nat La + 51 V, 159 Tb + 51 V, and 208 Pb + 51 V reactions. Then, we
started to search for new element, element 119 in the 248 Cm + 51 V reaction in January, 2018. In 2019, we continued to search forelement 119 in the 248 Cm + 51 V reaction. We also developed the new separator GARIS III on the beam line of the upgraded RILAC,
i.e. Superconducting RIKEN heavy-ion Linear ACcelerator (SRILAC). The SRILAC + GARIS III setup will be ready for the SHE
experiments in 2020.
(2) Decay spectroscopy of the heaviest nuclei
We developed a novel detector, referred to as an “α-TOF detector,” for correlated measurements of atomic masses and decay
properties of low-yield, short-lived radioactive isotopes using a multi-reflection time-of-flight mass spectrograph. By correlating
measured time-of-flight signals with decay events, it can suppress background events and obtain accurate, high-precision mass andhalf-life values even in cases of very low event rates. An oﬄine test of the α-TOF detector showed that the time-of-flight detection
eﬃciency for 5.48 MeV α-particles is more than 90% and yields a time resolution of 250.6(68) ps and an α-energy resolution of
141.1(9) keV.
(3) Study of reaction mechanisms for production of the heaviest nuclei
SHE nuclei have been produced by complete fusion reactions of two heavy nuclei. However, the reaction mechanism of thefusion process is still not well understood both theoretically and experimentally. We measured excitation functions for the quasielastic
scattering of the 248 Cm+22 Ne, 248 Cm+26 Mg, and 238 U+48 Ca reactions using GARIS at RILAC. The quasielastic barrier distributions
were successfully extracted for these systems, and compared with coupled-channels calculations. It was found that the results can beutilized to locate the optimal energy for the future searches for undiscovered superheavy nuclei.
(4) Study of chemical properties of the heaviest elements
Chemical characterization of newly-discovered SHEs is an extremely interesting and challenging subject in modern nuclear andradiochemistry. In collaboration with Nuclear Chemistry Research Team of RIKEN Nishina Center, we are developing SHE production systems as well as rapid single-atom chemistry apparatuses for chemistry studies of SHEs. We installed a gas-jet transportsystem to the focal plane of GARIS at RILAC. This system is a promising approach for exploring new frontiers in SHE chemistry: thebackground radiations from unwanted products are strongly suppressed, the intense primary heavy-ion beam is absent in the gas-jet
chamber, and hence the high gas-jet extraction yield is attained. Furthermore, the beam-free conditions make it possible to investigate
new chemical systems. In 2019, we continued to develop an ultra-rapid gas-chromatograph apparatus at the focal plane of GARIS forthe gas chemistry of SHEs. This apparatus consists of an RF carpet gas cell and a cryo-gas-chromatograph column with a Si detector
array. For the aqueous chemistry, we also developed a flow solvent extraction apparatus which consisted of a continuous dissolution
apparatus, a flow extraction apparatus, and a liquid scintillation counter.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Members
Team Leader
Hiromitsu HABA
Research & Development Scientist
Daiya KAJI
Special Postdoctoral Researcher
Tomohiro HAYAMIZU
Visiting Scientists
Satoshi ADACHI (Kyushu Univ.)
Marc ASFARI (Inst. Pluridisciplinaire Hubert Curien)
Mahananda DASGUPTA (Australian Nat’l Univ.)
Olivier DORVAUX (Strasbourg Univ.)
Benoit Jean-Paul GALL (Strasbourg Univ./Inst. Pluridisciplinaire Hubert Curien)
Zaiguo GAN (Inst. of Modern Phys.)
Shintaro GO (Kyushu Univ.)
David HINDE (The Australian Nat’l Univ.)
Student Trainees
Masato HIGASHI (Kyushu Univ.)
Tamito KAI (Kyushu Univ.)
Kieran KESSACI (IPHC Strasbourg/Strasbourg Univ.)
Ikuto MURAKAMI (Kyushu Univ.)
Yuto NAGATA (Kyushu Univ.)

Minghui HUANG (Inst. of Modern Phys.)
Hiroyuki KOURA (JAEA)
Daisuke NAGAE (Kyushu Univ.)
Satoshi SAKAGUCHI (Kyushu Univ.)
Mirei TAKEYAMA (Yamagata Univ.)
Masaomi TANAKA (Kyushu Univ.)
Taiki TANAKA (The Australian Nat’l Univ.)
Huabin YANG (Inst. of Modern Phys.)Zhiyuan ZHANG (Inst. of Modern Phys.)
Natsuki NAITO (Kyushu Univ.)
Mako OSADA (Kyushu Univ.)
Kazuya SHIRASAKA (Kyushu Univ.)
Yoshihide SUEKAWA (Kyushu Univ.)

List of Publications & Presentations
Publications[Original papers]
S. Ahmed, E. Altiere, T. Andalib, M. J. Barnes, B. Bell, C. P. Bidinosti, Y. Bylinsky, J. Chak, M. Das, C. A. Davis, F. Fischer, B. Franke,
M. T. W. Gericke, P. Giampa, M. Hahn, S. Hansen-Romu, K. Hatanaka, T. Hayamizu, B. Jamieson, D. Jones, K. Katsika, S. Kawasaki,
T. Kikawa, W. Klassen, A. Konaka, E. Korkmaz, F. Kuchler, L. Kurchaninov, M. Lang, L. Lee, T. Lindner, K. W. Madison, J. Mammei,
R. Mammei, J. W. Martin, R. Matsumiya, E. Miller, T. Momose, R. Picker, E. Pierre, W. D. Ramsay, Y. -N. Rao, W. R. Rawnsley,
L. Rebenitsch, W. Schreyer, S. Sidhu, S. Vanbergen, W. T. H. van Oers, Y. X. Watanabe, and D. Yosifov, “Fast-switching magnet
serving a spallation-driven ultracold neutron source,” Phys. Rev. Accel. Beams 22, 102401-1–16 (2019).
T. Tanaka, K. Morita, K. Morimoto, D. Kaji, H. Haba, R. A. Boll, N. T. Brewer, S. Van Cleve, D. J. Dean, S. Ishizawa, Y. Ito, Y. Komori,K. Nishio, T. Niwase, B. C. Rasco, J. B. Roberto, K. P. Rykaczewski, H. Sakai, D. W. Stracener, and K. Hagino, “Fusion dynamics for
hot fusion reactions to synthesize superheavy nuclei revealed in quasielastic barrier distributions,” Phys. Rev. Lett. 124, 052502-1–96(2020).
Y. Wang, Y. Wittwer, J. Zhang, J. Yang, H. Haba, Y. Komori, T. Yokokita, S. Cao, F. Fan, R. Eichler, A. Türler, and Z. Qin, “Massspectrometric speciation of metal-carbonyls in the gas phase,” PSI Annual Report 2018, Laboratory of Radiochemistry, 13–14 (2019).
Y. Kasamatsu, N. Kondo, K. Nakamura, Y. Kuboki, H. Ninomiya, Y. Shigekawa, E. Watanabe, Y. Yasuda, K. Toyomura, M. Nagase,
T. Yokokita, Y. Komori, H. Haba, T. Yoshimura, H. Itabashi, and A. Shinohara, “Solvent extraction of Zr and Hf from HCl by Aliquat
336 using a flow-type extraction apparatus toward online chemical studies of element 104, rutherfordium,” Solv. Extr. Ion Exch 38,
318–327 (2020).
T. Niwase, M. Wada, P. Schury, H. Haba, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, K. Morimoto, K. Morita, M. Rosenbusch,
H. Wollnik, T. Shanley, and Y. Benari, “Development of an “α-TOF” detector for correlated measurement of atomic masses and decay
properties,” Nucl. Instrum. Methods Phys. Res. A 953, 163198-1–8 (2020).
Y. Sakemi, H. Nagahama, T. Hayamizu, N. Ozawa, K. S. Tanaka, K. Harada, A. Uchiyama, and J. Tsutsumi, “Present status of fundamental
symmetry experimental project with laser cooled heavy elements,” CNS Annual Report 2018, 23–24 (2020).
N. Ozawa, H. Nagahama, T. Hayamizu, J. Tsutsumi, K. S. Tanaka, K. Harada, A. Uchiyama, and Y. Sakemi, “Development of a novelsurface ionizer for the electron EDM measurement using francium,” CNS Annual Report 2018, 25–26 (2020).

[Review articles]
H. Haba, “The rewards and challenges of expanding the periodic table,” Chem. Eng. News, August 5, 36–37 (2019).
Ӌ৔޺ޫ, ʮୈ 8 प‫ظ‬ͷ৽‫ݩ‬ૉΛ‫ٻ‬Ίͯʯ, ์ࣹԽֶ 40, 14–20 (2019).
Ӌ৔޺ޫ, ʮ೔ຊͷ‫ʹऀڀݚ‬ΑΔ৽‫ݩ‬ૉͷ୳ࡧͱप‫ظ‬දͷ։୓—χοϙχ΢Ϝ, 93 ൪‫ݩ‬ૉ, χϗχ΢Ϝɻ͞ΒͳΔ৽‫ݩ‬ૉΛ‫ٻ‬Ίͯ—ʯ, Խֶͱ޻‫ ۀ‬72, 944–945 (2019).

[Books]- 277 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

๛ౢް࢙, Ӌ৔޺ޫ, ʮ௒ॏ‫ݩ‬ૉԽֶ–༹ӷԽֶʯ, in ʮϑϩϯςΟΞγϦʔζ 2 ௒ॏ‫ݩ‬ૉԽֶͷ࠷લઢʯ, Ӭ໨་Ұ࿠ʢฤஶʣ, pp. 41–48,
೔ຊ์ࣹԽֶձ, 2019 ೥ 9 ݄ 1 ೔.

[Proceedings]
H. Haba for RIKEN SHE Collaboration, “Present status and perspectives of SHE researches at RIKEN,” in Proceedings of the International
Symposium on Exotic Nuclei, Petrozavodsk, Russia, 10–15 September 2018, Yu. E. Penionzhkevich, Yu. G. Sobolev (Eds.), (World
Scientific Publishing Co. Pte. Ltd., 2020), pp. 192–199.

Presentations[International conferences/workshops]
H. Haba (invited), “Production and applications of radioisotopes at RIKEN RI Beam Factory,” SHE Science Symposium, Oak Ridge,
USA, May 30, 2019.
H. Haba (invited), “Synthesis and chemistry of new elements at RIKEN,” 9th European Chemistry Congress, Berlin, Germany, June
17–18, 2019.
A. Yakushev, L. Lens, Ch. E. Düllmann, M. Asai, M. Block, H. Brand, H. M. David, J. Despotopulos, A. Di Nitto, K. Eberhardt, U. Forsberg, P. Golubev, M. Götz, S. Götz, H. Haba, L. Harkness-Brennan, W. Hartmann, R. -D. Herzberg, D. Hinde, J. Hoﬀmann, A. Hübner,
E. Jäger, M. Jourdan, D. Judson, J. Khuyagbaatar, B. Kindler, Y. Komori, J. Konki, J. V. Kratz, J. Krier, N. Kurz, M. Laatiaoui,
S. Lahiri, B. Lommel, M. Maiti, A. Mistry, Ch. Mokry, K. Moody, Y. Nagame, J. P. Omtvedt, P. Papadakis, V. Pershina, T. Reich,
D. Rudolph, J. Runke, L. Samiento, T. K. Sato, M. Schädel, P. Scharrer, B. Schausten, D. Shaughnessy, J. Steiner, P. Thörle-Pospiech,
A. Toyoshima, N. Trautmann, K. Tsukada, J. Uusitalo, K. -O. Voss, A. Ward, M. Wegrzecki, N. Wiehl, E. Williams, and V. Yakusheva(invited), “Chemical studies of superheavy elements at a recoil separator, with a focus on Fl,” 6th International Conference on theChemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
M. Götz, Ch. E. Düllmann, A. Yakushev, M. Asai, J. Ballof, A. Di Nitto, K. Eberhardt, S. Götz, H. Haba, E. Jäger, Y. Kaneya, Y. Komori,
J. V. Kratz, J. Krier, B. Lommel, A. Mitsukai, Y. Nagame, T. K. Sato, A. Toyoshima, K. Tsukada, V. Wolter, and V. Yakusheva (poster),“In-situ synthesis of volatile transition metal carbonyl complexes with short-lived radioisotopes,” 6th International Conference on theChemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
Z. Qin, Y. Wang, S. Cao, J. Zhang, J. Yang, H. Haba, F. Fan, Y. Komori, T. Yokokita, K. Morimoto, D. Kaji, Y. Wittwer, R. Eichler,
and A. Türler (poster), “The study of rhenium pentacarbonyl complexes using single-atom chemistry in gas phase,” 6th International
Conference on the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
Y. Wang, Y. Wittwer, J. Zhang, J. Yang, H. Haba, Y. Komori, T. Yokokita, S. Cao, F. Fan, R. Eichler, A. Türler, and Z. Qin (oral), “Thespecies identification of Mo, W, and Re carbonyl complexes with laserablation time-of-flight mass-spectrometry,” 6th International
Conference on the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
L. Lens, A. Yakushev, Ch. E. Düllmann, M. Asai, M. Block, H. Brand, M. Dasgupta, H. M. David, J. Despotopulos, A. Di Nitto,
K. Eberhardt, M. Götz, P. Golubev, S. Götz, H. Haba, L. Harkness-Brennan, F. P. Heßberger, R. -D. Herzberg, D. Hinde, J. Hoﬀmann,
A. Hübner, E. Jäger, D. Judson, J. Khuyagbaatar, B. Kindler, Y. Komori, J. Konki, J. V. Kratz, J. Krier, N. Kurz, M. Laatiaoui, S. Lahiri,
B. Lommel, M. Maiti, A. K. Mistry, C. Mokry, K. Moody, Y. Nagame, J. P. Omtvedt, P. Papadakis, V. Pershina, A. Roth, D. Rudolph,
J. Runke, L. Sarmiento, M. Schädel, P. Scharrer, T. Sato, D. Shaughnessy, B. Schausten, J. Steiner, P. Thörle-Pospiech, N. Trautmann,
K. Tsukada, J. Uusitalo, A. Ward, M. Wegrzecki, E. Williams, N. Wiehl, and V. Yakusheva (poster), “Optimizations of the TASCACOMPACT setup towards chemical studies of nihonium (element 113),” 6th International Conference on the Chemistry and Physics of
the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
T. Niwase, M. Wada, P. Schury, Y. Ito, S. Kimura, D. Kaji, M. Rosenbusch, Y. Watanabe, Y. Hirayama, H. Miyatake, J. Y. Moon,
H. Ishiyama, K. Morimoto, H. Haba, T. Tanaka, S. Ishizawa, A. Takamine, K. Morita, and H. Wollnik (poster), “Development and first
results from a novel “α-ToF” detector used with a multi-reflection time-of-flight mass spectrograph,” 6th International Conference on
the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
T. Tanaka, K. Morita, K. Morimoto, D. Kaji, H. Haba, R. A. Boll, N. T. Brewer, S. V. Cleve, D. J. Dean, S. Ishizawa, Y. Ito, Y. Komori,K. Nishio, T. Niwase, B. C. Rasco, J. B. Roberto, K. Rykaczewski, H. Sakai, D. W. Stracener, and K. Hagino (oral), “Fusion dynamics
for hot fusion reactions revealed in quasielastic barrier distributions,” 6th International Conference on the Chemistry and Physics of theTransactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
M. Wada, P. Schury, H. Miyatake, Y. X. Watanabe, Y. Hirayama, H. Wollnik, S. Kimura, S. Ishizawa, T. Niwase, M. Rosenbusch, D. Kaji,
K. Morimoto, H. Haba, I. Takamine, T. Tanaka, H. Ishiyama, Y. Ito, J. Y. Moon, and K. Morita (invited), “SHE-Mass-II setup for direct
mass measurement of hot-fusion superheavy nuclides,” 6th International Conference on the Chemistry and Physics of the Transactinide
Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
Y. Ito, P. Schury, M. Wada, F. Arai, H. Haba, Y. Hirayama, S. Ishizawa, D. Kaji, S. Kimura, H. Koura, M. Maccormick, H. Miyatake,J. -Y. Moon, K. Morimoto, K. Morita, M. Mukai, I. Murray, T. Niwase, K. Okada, A. Ozawa, M. Rosenbusch, A. Takamine, T. Tanaka,
Y. Watanabe, H. Wollnik, and S. Yamaki (oral), “Direct mass measurements of mendelevium isotopes in the vicinity of the N =152 deformed shell-closure,” 6th International Conference on the Chemistry and Physics of the Transactinide Elements (TAN19),
Wilhelmshaven, Germany, August 25–30, 2019.
H. Haba (invited), “Present status and perspectives of superheavy element researches at RIKEN,” XXXVI’th Mazurian Lakes Conference
on Physics, Piaski, Poland, September 1–7, 2019.
H. Haba (invited), “RI production—Chemistry of new elements to diagnosis and treatment of cancer—,” Tsukuba Conference 2019,
Tsukuba, Japan, October 2–4, 2019.
Y. Kasamatsu, H. Ninomiya, S. Hayami, M. Nagase, E. Watanabe, Y. Shigekawa, N. Kondo, H. Haba, T. Yokokita, Y. Komori, D. Mori,Y. Wang, K. Ghosh, M. Kaneko, and A. Shinohara (poster), “Coprecipitation of nobelium with samarium hydroxide,” The 4th Interna-- 278 -

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tional Symposium on Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
Z. Qin, Y. Wang, S. W. Cao, J. C. Zhang, F. L. Fang, J. Yang, H. Haba, Y. Komori, T. Yokokita, K. Morimoto, D. Kaji, Y. Wittwer,
R. Eichler, and A. Türler (invited), “Towards the bohrium carbonyl complexes in gas phase,” The 4th International Symposium on
Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
Y. Wang, Y. Wittwer, J. Zhang, S. Cao, Y. Komori, T. Yokokita, Y. Shigekawa, F. Fan, J. Yang, H. Haba, R. Eichler, A. Türler, and Z. Qin(oral), “Species identification of Re carbonyls using laser-ablation time-of-flight mass-spectrometer,” The 4th International Symposiumon Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
T. Yokokita, Y. Kasamatsu, E. Watanabe, Y. Komori, H. Ninomiya, Y. Wang, D. Mori, K. Ghosh, A. Shinohara, and H. Haba (oral),“Anion exchange of Rf, Zr, Hf, and Th in H2 SO4 ,” The 4th International Symposium on Superheavy Elements (SHE2019), Hakone,
Japan, December 1–5, 2019.
T. Niwase, M. Wada, P. Schury, Y. Ito, S. Kimura, D. Kaji, M. Rosenbusch, Y. X. Watanabe, Y. Hirayama, H. Miyatake, J. Y. Moon,
H. Ishiyama, K. Morimoto, H. Haba, T. Tanaka, S. Ishizawa, A. Takamine, K. Morita, and H. Wollnik (oral), “Correlation measurement of precision mass and decay properties of nuclei via MRTOF-MS with α-ToF detector,” The 4th International Symposium on
Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
M. Rosenbusch, M. Wada, P. Schury, S. Iimura, H. Haba, Y. Hirayama, H. Ishiyama, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, J. Y. Moon, K. Morimoto, T. Tanaka, T. Niwase, A. Takamine, K. Morita, Y. X. Watanabe, and H. Wollnik (oral), “Dynamic
ejection-field correction for MR ToF mass spectrometry of SHE using arbitrary mass references,” The 4th International Symposium on
Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
H. Haba (plenary), “Production and applications of radioisotopes at RIKEN RI Beam Factory—Search for new elements through diagnosis
and therapy of cancer—,” The 10th International Conference on Isotopes (10ICI), Kuala Lumpur, Malaysia, February 3–7, 2020.
H. Haba (invited), “Present status and perspectives of superheavy element chemistry at RIKEN,” The 10th International Conference on
Isotopes (10ICI), Kuala Lumpur, Malaysia, February 3–7, 2020.

[Seminars]
H. Haba, “Production of radioisotopes for application Studies at RIKEN RI Beam Factory,” Seminar at Institute of Modern Physics (IMP),
Lanzhou, China, August 12, 2019.
H. Haba, “Production of radioisotopes for application Studies at RIKEN RI Beam Factory,” IFIN-HH Seminar at Horia Hulubei National
Institute for R&D in Physics and Nuclear Engineering, Bucharest, Rumania, October 21, 2019.
H. Haba, “Production of radioisotopes for application studies at RIKEN RI Beam Factory,” Seminar at Sunway University, Selangor,
Malaysia, February 10, 2020.

[Domestic conferences/workshops]Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ৽‫ݩ‬ૉԽֶͷల๬ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑ଠ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnikʢ‫ޱ‬಄ൃදʣ, ʮMRTOF-MS Λ༻͍ͨ 207 Ra ͷਫ਼ີ࣭ྔ–่յಛੑଌఆʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
ૣ઒༏ଠ, ࡔ‫ޱ‬ҁ, ଜాਅ༏, দଜՆ‫ل‬, ౻পमฏ, தౡ࿕‫ٱ‬, ּদྑਸ, ࣰ‫ްݪ‬, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େً, ໼ೲ৻໵, Ӌ৔޺ޫ,ԣࢁ໌඙ʢ‫ޱ‬಄ൃදʣ, ʮU+p ‫ ͼٴ‬Th+Li ൓ԠʹΑΔ Np ಉҐମྭ‫਺ؔى‬ͷ࡞੒ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ
͖, 2019 ೥ 9 ݄ 24–26 ೔.
ԣ๺୎໵, ּদྑਸ, ౉ᬒӯհ, খ৿༗‫ࢠر‬, ೋ‫ٶ‬लඒ, Ԧ༸, ৿େً, ΰʔγϡίʔελϒ, ࣰ‫ްݪ‬, Ӌ৔޺ޫʢ‫ޱ‬಄ൃදʣ, ʮེࢎ‫ܥ‬ʹ͓͚Δ Rf ͷӄΠΦϯަ‫׵‬ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
଎ਫᠳ, ೋ‫ٶ‬लඒ, ౉ᬒӯհ, ॏՏ༏େ, Ӭ੉কߒ, ּদྑਸ, ۙ౻੒ඒ, Ӌ৔޺ޫ, ԣ๺୎໵, খ৿༗‫ࢠر‬, ৿େً, Ԧ༸, ΰʔγϡίʔελϒ, ࠤ౻๬, ࣰ‫ްݪ‬ʢ‫ޱ‬಄ൃදʣ, ʮਫࢎԽαϚϦ΢Ϝ‫ڞ‬௜๏Λ༻͍ͨ 102 ൪‫ݩ‬ૉϊʔϕϦ΢Ϝͷ௜఼࣮‫ݧ‬ʯ, ೔ຊ์ࣹԽֶձ
ୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnikʢ‫ޱ‬಄ൃදʣ, ʮMRTOF + α-TOF Λ༻͍ͨ 207 Ra ͷ࣭ྔ–่յಛੑଌఆʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
҆ୡασΟΞ, ຤໦‫ܒ‬հ, ๛ౢް࢙, ௩ా࿨໌, Ӌ৔޺ޫ, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େًʢϙελʔൃදʣ, ʮHF/HNO3 ਫ༹ӷதʹ
͓͚Δ Nb, Ta, Pa ͷӄΠΦϯަ‫ݧ࣮׵‬ʙDb ϑοԽ෺ࡨମͷਪఆʹ޲͚ͯʙʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖,2019 ೥ 9 ݄ 24–26 ೔.
৿ాྋխ, ૣ઒༏ଠ, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େً, Ӌ৔޺ޫ, ּদྑਸ, ࣰ‫ްݪ‬, ԣࢁ໌඙ʢϙελʕൃදʣ, ʮ239 Np ෳ߹֩‫͓ʹܥ‬͚Δ֩෼྾அ໘ੵଌఆʹΑΔ‫ي‬ಓ֯ӡಈྔͷਪఆʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ৽‫ݩ‬ૉΛ୳ͦ͏!ʯ, ೔ຊԽֶձ ‫ͪͨ܅‬ͷকདྷͱԽֶͷະདྷ ౦େͰա͢͝Խֶͳि຤, จ‫ژ‬, 2019 ೥ 10 ݄
20 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ113 ൪χϗχ΢Ϝͷൃ‫ݟ‬ʯ, ࠃࡍप‫ظ‬ද೥ 2019 ಛผలΦʔϓχϯάΠϕϯτ, ࢁ‫ܗ‬, 2019 ೥ 11 ݄ 3 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ‫ݩ‬ૉΛͭ͘Ζ͏ʂʯ, αΠΤϯεΞΰϥࠃࡍप‫ظ‬ද೥ಛผ‫ا‬ը ‫ݩ‬ૉ‫ݕ‬ఆ 2019@౦‫ژ‬, ߐ౦, 2019 ೥ 11 ݄
16 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮϥδΦΞΠιτʔϓͷ੡଄ͱԠ༻—৽‫ݩ‬ૉͷ୳ࡧ͔Β͕Μͷ਍அɾ࣏ྍ·Ͱ—ʯ, 2019 ೥౓೔ຊΞΠιτʔϓ‫ڠ‬ձγϯϙδ΢ϜʮPETɾΠϝʔδϯά‫ڀݚ‬ͷ࠷લઢʙϥΠϑαΠΤϯεͱཧ޻ֶͷ༥߹ʙʯ, ઒࡚, 2019 ೥ 11 ݄ 22 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮཧ‫͚͓ʹݚ‬ΔϥδΦΞΠιτʔϓͷ੡଄ͱԠ༻ʙ৽‫ݩ‬ૉͷ୳ࡧ͔Β͕Μͷ਍அɾ࣏ྍ·Ͱʙʯ, ୈ 75 ճ์ࣹઢ‫ܭ‬ଌ‫ڀݚ‬ձ, ࿨ޫࢢ, 2020 ೥ 1 ݄ 18 ೔.
খᖒ௚໵, ௕ᖛ߂‫ق‬, ૣਫ༑༸, தଜ‫ܓ‬༎, খߴ߁র, ాத߳௡ੜ, େ௩ະདྷ, খ৿༗‫ࢠر‬, ࢢ઒༤Ұ, Ӌ৔޺ޫ, ্໺लथ, ञ‫ݟ‬ହ‫׮‬ʢ‫ޱ‬- 279 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

಄ൃදʣ,ʮϑϥϯγ΢Ϝ‫ࢠݪ‬ͷి‫ؾ‬૒‫ࢠۃ‬ೳ཰୳ࡧͷͨΊͷද໘ి཭ΠΦϯ‫ݯ‬ͷ։ൃʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020೥ʣ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ൧ଜढ़, ߴๆѪࢠ, ৿ాߒհ, H. Wollnikʢ‫ޱ‬಄ൃදʣ, ʮMRTOF+α-TOF Λ༻͍ͨ୹ण໋
α ่յ֩छͷ࣭ྔ–่յಛੑଌఆʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.

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Nuclear Science and Transmutation Research Division
Superheavy Element Research Group
Superheavy Element Device Development Team
1. Abstract
A gas-filled recoil ion separator has been used as a main experimental device for the study of superheavy elements. This team isin charge of maintaining, improving, developing, and operating the separators and related devices. In the RIBF facility, three gas-filled
recoil ion separators are installed at RILAC and RRC facility. One is GARIS that is designed for a symmetric reaction such as coldfusion reaction, and the other two are developed for an asymmetric reaction such as hot-fusion reaction, GARIS-II and GARIS-III.
New elements 278 113 were produced by 70 Zn + 209 Bi reaction using GARIS. Further the new element search Z > 118 is currently inprogress by using GARIS-II and GARIS-III.

2. Major Research Subjects(1) Maintenance of GARIS, GARIS-II and development of new separator GARIS-III(2) Maintenance and development of detector and DAQ system for superheavy element research(3) Maintenance and development of target system for GARIS, GARIS-II and GARIS-III

3. Summary of Research Activity
The GARIS-II and III are newly developed which has an acceptance twice as large as existing GARIS, in order to realize higher
transmission. A new element search program aiming to element 119 was started using GARIS-II. And new separator GARIS-III
was developed and installed into the RILAC experimental hall. It will be ready for operation in the physical year 2020 after somecommissioning works. We will also oﬀer user-support if a researcher wishes to use the devices for his/her own research program.

Members
Team Leader
Kouji MORIMOTO
Research/Technical Scientists
Masaki FUJIMAKI (concurrent: Senior Technical Scientist)

Daiya KAJI (Technical Scientist)

Postdoctoral Researchers
Pierre BRIONNET

Sota KIMURA

Junior Research Associates
Satoshi ISHIZAWA

Toshitaka NIWASE

Visiting Scientists
Shin-ichi GOTO (Niigata Univ.)
Eiji IDEGUCHI (Osaka Univ.)
Yuta ITO (JAEA)

Katsuhisa NISHIO (JAEA)
Fuyuki TOKANAI (Yamagata Univ.)

Student Trainees
Hayato NUMAKURA (Yamagata Univ.)
Yoshiki TAKAHASHI (Niigata Univ.)

Hiroki TSUNODA (Niigata Univ.)

List of Publications & Presentations
Publications[Original papers]
S. Ishizawa, K. Morimoto, D. Kaji, T. Tanaka, and F. Tokanai, “Improvement of the detection eﬃciency of a time-of-flight detector for
superheavy element search,” Nucl. Instrum. Methods Phys. Res. A 960, 163614 (2020).
T. Niwase, M. Wada, P. Schury, H. Haba, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, K. Morimoto, K. Morita, M. Rosenbusch,
H. Wollnik, T. Shanley, and Y. Benari, “Development of an “α-TOF” detector for correlated measurement of atomic masses and decay
properties,” Nucl. Instrum. Methods Phys. Res. A, 953, 163198 (2020).
H. Numakura, K. Morimoto, D. Kaji, K. Kosugi, C. Horikawa, S. Ishizawa, M. Takeyama, and F. Tokanai, “Evaluation of a backilluminated solid state detector with thin dead layer for super heavy element research,” Jpn. J. Appl., Phys. 59, 066004 (2020).

[Review articles]ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. MOON, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnik, ʮMRTOF+α-TOF Λ༻͍ͨ 207 Ra ͷ࣭ྔ-่յಛੑଌఆʯ,์ࣹԽֶ ୈ 41 ߸ 2020 ೥ 3 ݄.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Presentations[International conferences/workshops]
K. Morimoto (invited), “The discovery of element 113,” TAN 19, Wilhelmshaven, Germany, August 2019.
S. Ishizawa (oral), K. Morimoto, D. Kaji, T. Tanaka, and F. Tokanai, “Improvement of the detection eﬃciency of a time-of-flight detector for superheavy element search,” The 2019 IEEE Nuclear Science Symposium (NSS) and Medical Imaging Conference (MIC),
Manchester, UK, October 26–November 5, 2019.
P. Brionnet (oral), “First measurement of the reaction 51 V+159 Tb → 210 Ra∗ on GARIS-II,” The 4th International Symposium on Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
T. Niwase (oral), M. Wada, P. Schury, Y. Ito, D. Kaji, M. Rosenbusch, Y. X. Watanabe, Y. Hirayama, J. Y. MOON, H. Ishiyama, T. Tanaka,
A. Takamine, S. Kimura, K. Morimoto, H. Haba, S. Ishizawa, K. Morita, H. Miyatake, and H. Wollnik, “Correlation measurement ofprecision mass and decay properties of nuclei via MRTOF-MS with α-ToF detector,” The 4th International Symposium on Superheavy
Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
S. Ishizawa (poster), K. Morimoto, D. Kaji, T. Tanaka, and F. Tokanai, “Improvement of the detection eﬃciency of a time-of-flight detector
with a large eﬀective area for superheavy element search,” The 4th International Symposium on Superheavy Elements (SHE2019),
Hakone, Japan, December 1–5, 2019.
T. Niwase (poster), M. Wada, P. Schury, Y. Ito, S. Kimura, D. Kaji, M. Rosenbusch, Y. X. Watanabe, Y. Hirayama, H. Miyatake,J. Y. Moon, H. Ishiyama, K. Morimoto, H. Haba, T. Tanaka, S. Ishizawa, A. Takamine, K. Morita, and H. Wollnik, “Development andfirst results from a novel “α-TOF” detector used with a multi-reflection time-of-flight mass spectrograph,” TAN 19, Wilhelmshaven,
Germany, August 2019.
H. Numakura (poster), C. Horikawa, K. Morimoto, S. Ishizawa, M. Takeyama, and F. Tokanai, “Evaluation of dead-layer thickness of
SSD for SHE research,” The 19th International Conference on Solid State Dosimetry (SSD19), Hiroshima, September 15–20, 2019.
I. Murakami (poster), S. Sakaguchi, D. Kaji, K. Morimoto, T. Niwase, K. Morita et al., “Development of MCP ToF Detectors at Kyushu
University,” The 4th International Symposium on Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
K. Morimoto (oral), “Discovery of Nh and search for element 119,” nSHE RG Collaboration Meeting. Oak Ridge National Laboratory
and the University of Tennessee Knoxville, US, May 30–June 1, 2019.
D. Kaji (oral), “GARIS-2/-3 performance,” nSHE RG Collaboration Meeting. Oak Ridge National Laboratory and the University ofTennessee Knoxville, US, May 30–June 1, 2019.
P. Brionnett (oral), “Data analysis I,” nSHE RG Collaboration Meeting. Oak Ridge National Laboratory and the University of Tennessee
Knoxville, US, May 30–June 1, 2019.
S. Ishizawa (oral), “Optimization of ToF system,” nSHE RG Collaboration Meeting. Oak Ridge National Laboratory and the Universityof Tennessee Knoxville, US, May 30–June 1, 2019.
S. Kimura (oral), “Determination of anchor via direct mass measurement with MR-TOF,” nSHE RG Collaboration Meeting. Oak Ridge
National Laboratory and the University of Tennessee Knoxville, US, May 30–June 1, 2019.
K. Morimoto (oral), “Present status and plans of GARIS, GARIS-II and GARIS-III,” SSRI-PNS Collaboration Meeting 2019, Nishina
hall, Nishina Bldg. 2F, September 4, 2019.

[Domestic conferences/workshops]ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. MOON, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnik, ʮMRTOF-MS Λ༻͍ͨ 207 Ra ͷਫ਼ີ࣭ྔ-่յಛੑଌ
ఆʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. MOON, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnik, ʮMRTOF+α-TOF Λ༻͍ͨ 207Ra ͷ࣭ྔ-่յಛੑଌ
ఆʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձ (2019), ͍Θ͖, 2019 ೥ 9 ݄.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. MOON, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ൧ଜढ़, ߴๆѪࢠ, ৿ాߒհ, H. Wollnik, ʮMRTOF+α-TOF Λ༻͍ͨ୹ण໋ α ่յ֩छͷ࣭ྔ-่յಛੑଌఆʯ, ೔ຊ෺ཧֶձ ୈ 75 ճ೥࣍େձ (2020 ೥), ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄.

Awardsఉ੉‫ོڿ‬, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձ (2019), एख༏लൃද৆ 2019 ೥ 9 ݄

Others৿ຊ޾࢘, ཧԽֶ‫ॴڀݚ‬ઋ୆஍۠ Ұൠެ։, ʮ৽‫ݩ‬ૉʮχϗχ΢Ϝʯͷൃ‫ͳͨ৽ͱݟ‬ల։ʯ, ཧԽֶ‫ ॴڀݚ‬ઋ୆஍۠, 2019 ೥ 07 ݄
27 ೔.

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Nuclear Science and Transmutation Research Division
Astro-Glaciology Research Group
Summary of Research Activities

Our Astro-Glaciology Research Group promotes both experimental and theoretical studies to open up the new interdisciplinary
research field of astro-glaciology, which combines astrophysics, astrochemistry, glaciology, and climate science.
On the experimental side, we measure isotopic and ionic concentrations in ice cores drilled at Dome Fuji station, Antarctica,
in collaboration with the National Institute of Polar Research (NIPR, Tokyo). Here, the ice cores are time capsules which preserve
atmospheric information of the past. In particular, the ice cores obtained around the Dome Fuji site are very unique, because they
contain much more information on the stratosphere than any other ice cores obtained from elsewhere on Earth. This means that wehave significant advantages in using Dome Fuji ice cores if we wish to study the Universe, since UV photons, gamma-rays, and highenergy protons emitted by astronomical phenomena aﬀect the atmosphere of the stratosphere. Our principal aim is thus to acquire andinterpret information preserved in ice cores regarding:• Signatures of past volcanic eruptions and solar cycles;• Relationships between climate change and volcanic activity, and climate change and solar activity as well;• Traces of past supernovae in our galaxy, in order to understand better the rate of galactic supernova explosions.

Moreover, we are promoting experimental projects on:• Development of an automated laser melting sampler for analyzing ice cores with high depth resolution and high through-put;• Development of precise analytical techniques of high sensitivity for analyzing ice cores;• The application of analytical methods to measure isotopes developed for ice cores to archaeological artifacts;• The evolution of molecules in space.

On the theoretical side, we are simulating numerically:• Chemical eﬀects of giant solar flares and supernovae on the Earth’s atmosphere;• The explosive and the r-process nucleosynthesis in core-collapse supernovae.

Combining our experimental evidence and theoretical simulations, we are promoting the researches mentioned above. In particular,
climate change is the most critical issue facing the world in the 21st century. It is also emphasized that the frequency of supernova
explosions in our galaxy has not yet been fully understood, and this is a crucial key to understand of the r-process nucleosynthesis, oneof the goals of the Nishina Center. We note that our subjects all will contribute to an understanding relationships between the Universe
and Earth.

Members
Director
Yuko MOTIZUKI
Research/Technical Scientists
Kazuya TAKAHASHI (Senior Research Scientist)

Yoichi NAKAI (Senior Research Scientist)

Technical Staﬀ I
Yu Vin SAHOO
Senior Visiting Scientists
Yasushige YANO (RIKEN/Nishina Memorial Foundation)

Kunihiko KODERA (Meteorological Res. Inst.)

Visiting Scientists
Hideharu AKIYOSHI (Nat’l Inst. for Environmental Studies)
Akira HORI (Kitami Inst. of Tech.)
Kazuho HORIUCHI (Hirosaki Univ.)
Yoshinori IIZUKA (Hokkaido Univ.)

Naoyuki KURITA (Nagoya Univ.)
Hideki MADOKORO (Mitsubushi Heavy Industries, Ltd.)
Hideaki MOTOYAMA (Nat’l Inst. of Polar Res.)
Kenji TANABE (Okayama Univ. of Sci.)

Visiting Technician
Junya HIROSE (Fusion Tech. Co., Ltd.)
Student Trainee
Hisashi HAYAKAWA (Osaka Univ.)
Part-time Worker
Satomi NEGISHI (Part-time Worker I)- 283 -

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List of Publications & Presentations
Publications[Original papers]
T. Minami, K. Hatanaka, Y. Motizuki, Y. Nakai, and K. Takahashi, “A method of collecting trace amounts of vermilion from artifacts
for source estimation by sulfur isotope (δ34S) analysis: use of sulfur-free adhesive,” Journal of Archaeological Science: Reports 28,
102027, (2019).

[Books]๬݄༏ࢠ,ʮNewton ϥΠτ 2.0 प‫ظ‬දʯ (‫)ྗڠ‬, χϡʔτϯϓϨε, 2019 ೥ 12 ݄.
๬݄༏ࢠ,ʮχϡʔτϯࣜ௒ਤղ ࠷‫ʹڧ‬໘ന͍!! प‫ظ‬දʯ (‫)ྗڠ‬, χϡʔτϯϓϨε, 2019 ೥ 7 ݄.

Presentations[International conferences/workshops]
Y. Motizuki (invited), “The oxygen isotopic variations in a Dome Fuji (Antarctica) ice core—Relationships of the temperature proxy withsolar activity and oceanic variations,” WCRP/SPARC SATIO-TCS joint workshop on Stratosphere-Troposphere Dynamical Couplingin the Tropics, Kyoto, February 21–25, 2020.
H. Akiyoshi, Y. Nakai, Y. Motizuki, T. Imamura, and Y. Yamashita, “Ozone change simulations of Halloween event and Carrington
event using MIROC3.2 chemistry-climate model,” WCRP/SPARC SATIO-TCS joint workshop on Stratosphere-Troposphere Dynamical Coupling in the Tropics, Kyoto, February 21–25, 2020.
Y. V. Sahoo, K. Takahashi, Y. Nakai, Y. Motizuki, and H. Motoyama, “Annually-resolved water isotope measurements in a shallow ice
core (DFS10) for 60 meters depth,” (A poster paper), The Tenth Symposium on Polar Science, Tachikawa, December 3–5, 2019.
S. Fujita, K. Goto-Azuma, M. Hirabayashi, A. Hori, Y. Iizuka, Y. Motizuki, H. Motoyama, K. Takahashi, H. Enomoto, K. Fukui,
Y. Hoshina, F. Nakazawa, S. Sugiyama, and S. Surdylk, “Metamorphism of layered firn at Dome Fuji, Antarctica: Evolution of relations
between Near-infrared reflectivity and the other textural/chemical properties,” The Tenth Symposium on Polar Science, Tachikawa, December 3–5, 2019.
K. Kanzawa, F. Miyake, Y. Tada, K. Horiuchi, S. Otani, K. Sasa, Y. Motizuki, K. Takahashi, Y. Nakai, H. Motoyama, and H. Matsuzaki,“Variation of cosmogenic 10Be for cosmic ray event in 5480 BC from Antarctic Dome Fuji ice core,” The 8th East Asia Accelerator
Mass Spectrometry Symposium, Nagoya, Japan, December 3–6, 2019.
Y. Motizuki (invited), “Women in Astronomy: A view from a gender-imbalanced country,” IAU Symposium 358: “Astronomy for Equity,
Diversity and Inclusion—a roadmap to action within the framework of IAU centennial anniversary,” Tokyo, November 12–15, 2019.
Y. Motizuki (invited), “Historical supernova signatures in polar ice cores,” International workshop on “Historical supernovae, novae andother transient events,” Leiden, the Netherlands, October 14–18, 2019.

[Domestic conferences/workshops]
๬݄༏ࢠ, ߴ‫ڮ‬࿨໵, தҪཅҰ, Y. V. Sahoo, ຊࢁल໌, খࣉ๜඙, ʮೆ‫ۃ‬υʔϜ;͡ΞΠείΞ͔Β͙͞Δ‫ؾ‬Թมಈͱଠཅ‫׆‬ಈͱͷ૬ؔʯ, ೔ຊఱจֶձ 2020 ೥य़‫ق‬೥ձ, ͭ͘͹, 2020 ೥ 3 ݄ 16–19 ೔.
தҪཅҰ, ೔ߴ޺, ౉ล௚थ, ʮ௿ΤωϧΪʔΠΦϯͱ௿Թණද໘ͱͷ൓Ԡ࣮‫૷ݧ‬ஔ։ൃͷ‫ݱ‬ঢ়ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ,໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–19 ೔.
ੁᖒՂੈ, ࡾ୐ෙࠫ, ଟా༔അ, ງ಺Ұึ, େ୩Ꮺ, ࡫ެ࿨, ߴ‫౒ڮ‬, দଜਅणඒ, མ߹༔ଠ, ๬݄༏ࢠ, ߴ‫ڮ‬࿨໵, தҪཅҰ, ຊࢁल໌,দ࡚ߒ೭, ʮBC5480 ೥Ӊ஦ઢΠϕϯτʹ͓͚ΔυʔϜ;͡ΞΠείΞதͷ 10Be ͱ 36Cl ೱ౓ͷมಈʯ, ୈ 67 ճԠ༻෺ཧֶձय़
‫ֶق‬ज़ߨԋձ, ౦‫ژ‬, 2020 ೥ 3 ݄ 12–15 ೔.
ࡾ୐ෙࠫ, ງ಺Ұึ, ᓎҪ‫ٱܟ‬, ๬݄༏ࢠ, தҪཅҰ, ߴ‫ڮ‬࿨໵, ຊࢁल໌, দ࡚ߒ೭, ʮӉ஦ઢੜ੒֩छΛ༻͍ͨ‫ݩل‬લ 660 ೥ࠒͷӉ஦ઢΠϕϯτௐࠪʯ, ୈ 67 ճԠ༻෺ཧֶձय़‫ֶق‬ज़ߨԋձ, ౦‫ژ‬, 2020 ೥ 3 ݄ 12–15 ೔.
๬݄༏ࢠ (ট଴ߨԋ), ʮೆ‫ۃ‬ණதͷ֩छଘࡏൺ͔Βա‫ڈ‬ͷ‫ީؾ‬มಈΛ͙͞Δ—Ӊ஦ͱͷؔ࿈Λࢹ໺ʹʯ, ࡛‫ۄ‬େֶཧֶ෦෺ཧྔࢠ
ྗֶಛผߨٛ, ͍ͨ͞·, 2020 ೥ 1 ݄ 20 ೔.
ߴ‫ڮ‬࿨໵ (ট଴ߨԋ), ʮ‫ۃ‬ඍྔͷེԫಉҐମൺ෼ੳʹΑΔ, Ҩ੻͔Βग़౔ͨ͠ਫۜगͷ࢈஍ಉఆʯ, ୈ 370 ճΨεΫϩϚτάϥϑΟʔ‫ڀݚ‬ձಛผߨԋձ, ʮՊֶͱจԽʹߩ‫͢ݙ‬ΔΨεΫϩϚτάϥϑΟʔ—ਓΛ஌Δ, ஍‫ٿ‬Λ஌Δ, Ӊ஦Λ஌Δʯ, ౦‫ژ‬, 2019 ೥ 11 ݄
22 ೔.
๬݄༏ࢠ (ট଴ߨԋ), ʮυʔϜ;͡ΞΠείΞ͔Β୳Δ‫ީؾ‬มಈͱଠཅ‫׆‬ಈͱͷؔ܎ʯ, ౦‫ژ‬େֶେֶӃཧֶ‫ڀݚܥ‬Պ ஍‫ٿ‬࿭੕Պֶઐ߈ ࠤ౻‫ࣨڀݚ‬ηϛφʔ, ౦‫ژ‬, 2019 ೥ 10 ݄ 8 ೔.
ੁᖒՂੈ, ࡾ୐ෙࠫ, ଟా༔അ, ງ಺Ұึ, େ୩Ꮺ, ࡫ެ࿨, ๬݄༏ࢠ, ߴ‫ڮ‬࿨໵, தҪཅҰ, ຊࢁल໌, দ࡚ߒ೭, ʮυʔϜ;͡ΞΠείΞத 10Be ͱ 36Cl ೱ౓ͷଌఆʹΑΔ BC5480 ೥Ӊ஦ઢΠϕϯτͷௐࠪʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄
17–20 ೔.
தҪ ཅҰ, ೔ߴ޺, ౉෦௚थ, ʮ੕ؒਖද໘Λ໛ٖͨ͠௿Թණද໘ͱ௿ΤωϧΪʔΠΦϯͱͷ൓Ԡ࣮‫૷ݧ‬ஔͷ։ൃʯ(ϙελʔൃද),‫ࢠݪ‬িಥֶձୈ 44 ճ೥ձ, ௐ෍, 2019 ೥ 9 ݄ 5 ೔.
๬݄༏ࢠ (ট଴ߨԋ), ʮೆ‫ۃ‬ͷණ͔Βͻ΋ͱ͘Ӊ஦ͱ஍‫ٿ‬ͷྺ࢙ʯ, ެӹࡒஂ๏ਓࢁా௕ຬ঑ֶձ 30 प೥‫ه‬೦ߨԋձ, ઒࡚, 2019 ೥
7 ݄ 20 ೔.

Press releasesߴ‫ڮ‬࿨໵, ๬݄༏ࢠ, ೆ෢ࢤ, ʮ௒ඍྔེԫಉҐମൺ෼ੳΛߟ‫ʹֶݹ‬Ԡ༻͢Δ—‫ాژ‬Ҩ੻ͷग़౔඼͔Β੺৭‫إ‬ྉΛਫ਼ີ෼ੳ—ʯ, 2019೥ 11 ݄ 26 ೔. https://www.riken.jp/press/2019/20191126_2/- 284 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

K. Takahashi and Y. Motizuki, “Sticky tape: A key ingredient for mapping artifact origins,” March 9, 2020. https://www.riken.jp/
en/news_pubs/research_news/pr/2019/20191126_2/
RIKEN Science News blog; It Ain’t Magic, “Tape and vermilion: ingredients for mapping artifact origins,” by Adam Phillips, March 9,2020. https://itaintmagic.riken.jp/hot-off-the-press/tape-and-vermilion-ingredients-for-mappingartifact-origins/๬݄༏ࢠ (‫ݸ‬ผऔࡐड), ʮαΠΤϯε View: ஍‫ݹ࠷ٿ‬ͷණ ۷࡟ͤΑʯಡച৽ฉ‫ࣄه‬, 2019 ೥ 5 ݄ 26 ೔.

Outreach activities๬݄༏ࢠ (ট଴ߨԋ), ʮೆ‫ۃ‬ͷණ͔Βͻ΋ͱ͘Ӊ஦ͱ஍‫ٿ‬ͷྺ࢙ͱ‫ڥ؀ڀݚ‬ΛօͰ੔͍͑ͯ͘͜ͱͷେ੾͞ʯ, ߴদୈҰߴ౳ֶߍ(߳઒‫ )ݝ‬ཧ‫ஂݚ‬ମ‫ֶݟ‬, ࿨ޫ, 2019 ೥ 7 ݄ 29 ೔.
Y. V. Sahoo (Invited talk), “Studying and pursuing research positions in Japan,” Sakura Science High School Program promoted by
Department of Japan-Asia Youth Exchange Program in Science, Japan Society and Technology Agency, Wako, June 11, 2019.
๬݄༏ࢠ (ট଴ߨԋ), ʮೆ‫ۃ‬ͷණ͔Βͻ΋ͱ͘Ӊ஦ͱ஍‫ٿ‬ͷྺ࢙ʯ, KEK-TYL εΫʔϧཧ‫ࢠঁܥ‬Ωϟϯϓ 2019, ͭ͘͹, 2019 ೥ 4
݄ 3–4 ೔.

OthersK. Takahashi, “Detecting traces of sulfur in ice cores—An advanced isotope-measuring system can reveal insights about past environments
in shorter time,” RIKEN RESEARCH, SUMMER 2019, November 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Nuclear Transmutation Data Research Group
1. Abstract

The nuclear waste problem is an inevitable subject in nuclear physics and nuclear engineering communities. Since the Chicago
Pile was established in 1942, nuclear energy has become one of major sources of energy. However, nowadays the nuclear waste
produced at nuclear power plants has caused social problems. Minor actinide components of the waste have been studied well as a fuelin fast breeder reactors or ADS. Long-lived fission products (LLFP) in waste, on the other hand, have not been studied extensively. A
deep geological disposal has been a policy of several governments, but it is diﬃcult to find out location of the disposal station in termsof security, sociology and politics. To solve the social problem, a scientific eﬀort is necessary for nuclear physics community to findout eﬃcient methods for reduction of nuclear waste radioactivity. In the world-wide situation above, our Group aims to obtain reaction
data of LLFP at RIBF and other muon facilities for muon capture data. These data are necessary to design an accelerator-based system
for transmutation, and also may lead to a new discovery and invention for peaceful use of nuclear power and the welfare of humanity.

2. Major Research Subjects

The Group is formed by three research teams. The first two Teams, “Fast RI Data Team” and “Slow RI Data Team,” are in
charge of proton- and deuteron-induced reaction data of LLFP in inverse kinematics at RIBF. The third Team “Muon Data Team” isto obtain muon capture data of LLFP at muon facilities. All of the teams are focusing to obtain high-quality data which are essentiallynecessary to establish reliable reaction models. Each team has its own subjects and promotes LLFP reaction programs based on theirlarge experiences, techniques and skills.

3. Summary of Research Activity

In 2014, all the teams polished up experimental strategies, formed collaboration and prepared experiments. Physics runs forspallation reaction were successfully organized at RIBF in 2015–2017. The muon program started at RCNP, Osaka University inspring 2016 and the data for Pd isotopes were successfully obtained in 2017–2019 via in-beam method with DC beams at RCNP, andvia activation method with pulsed beams at J-PARC and ISIS-RAL/RIKEN facilities.
The reaction data obtained with both fast and energy-degraded beams at RIBF encouraged the nuclear data group of JAEA, anda new database called “JENDLE/ImPACT-2018” has been released. The new database has been generated by a newly developed
reaction model “DEURACS” which treats deuteron-induced reactions. DEURACS reproduces very well cross section data, and muchbetter than other reaction models. A simulation code “PHITS” has been re-coordianted to use the database information.
In December 2018, the Team leader, Hideaki Otsu, was invited to join Technical Meeting of IAEA, entitled “Novel Multidisciplinary Applications with Unstable Ion Beams and Complementary Techniques.” Our activity has been demonstrated and recognizedinternationally.

MemberGroup Director
Hiroyoshi SAKURAI (concurrent: Director, RI Physics Lab.)

List of Publications & Presentations
Publications[Original papers]
H. Okuno, H. Sakurai, Y. Mori, R. Fujita, and M. Kawashima, Proceedings of the Japan Academy, Series B 95, 430–439 (2019).

Presentations[International conferences/workshops]
H. Sakurai (invited), “A program for accelerator-based transmutation system for LLFP,” Fourth International Workshop on Technology
and Components of Accelerator-Driven Systems (TCADS-4), Antwerp, Belgium, October 14–17, 2019.

Press releasesʮʮ֩ͷΰϛʯ໰୊ղܾʹඞཁͳՃ଎‫ث‬ͷ֓೦ΛఏҊ—‫ط‬ଘͷ 300 ഒͷߴग़ྗॏཅࢠϏʔϜͷՃ଎͕Մೳʹ—ʯ, 2019 ೥ 8 ݄ 9 ೔.

Patents
Outreach activitiesᓎҪതّ, ʮʮ֩ͷΰϛʯΛΊ͙Δ‫ݩ‬ૉม‫΁׵‬ͷ௅ઓʯ, ࡾୋωοτϫʔΫେֶ, 2019 ೥ 9 ݄ 19 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Nuclear Transmutation Data Research Group
Fast RI Data Team
1. Abstract

Fast RI team aims at obtaining and accumulating the cross section data for long lived fission products (LLFPs) in order to explore
the possibility of using accelerator for nuclear transmutation.
LLFPs as nuclear waste have been generated continuously in nuclear power plants for wealth for human lives, while people
noticed the way of disposal has not necessarily been established, especially after the Fukushima Daiichi power plant disaster. One of
the ways to reduce the amount of LLFP or to recover them as recycled resources is nuclear transmutation technique.
RIBF facility has a property to generate such LLFP as a secondary beam and the beam species are identified by event by event.
Utilizing the property, absolute values of the cross section of various reactions on LLFPs are measured and accumulated as a database.

2. Major Research Subjects(1) Measurement of reaction products by the interaction of LLFPs with proton, deuteron, and photon to explore candidate reactions for the transmutation of LLFPs.
(2) Evaluation of the cross section data for the neutron induced reactions from the obtained data.

3. Summary of Research Activity
(1)
(2)
(3)
(4)

Acting as a collaboration hub on many groups which plan to take data using fast RI beams in RIBF facility.
Concentrating on taking data for proton and deuteron induced spallation reactions with inverse kinematics.
Accumulating the cross section data and evaluating them as evaluated nuclear data.
Evaluating cross section of neutron induced reaction on LLFP by collaborating with the nuclear model calculation and evaluation group.

Members
Team Leader
Hideaki OTSU (Concurrent: Team Leader, SAMURAI Team)
Visiting Scientists
Takashi TERANISHI (Kyushu Univ.)
Student Trainees
Keita NAKANO (Kyushu Univ.)

List of Publications & Presentations
Publications[Original papers]
H. Wang, H. Otsu, N. Chiga et al., “Enhancement of element production by incomplete fusion reaction with weakly bound deuteron,”Commun. Phys. 2, 78 (2019).
K. Nakano, Y. Watanabe, S. Kawase, H. Otsu et al., “Isotope production in proton-, deuteron-, and carbon-induced reactions on 93 Nb at
113 MeV/nucleon,” Phys. Rev. C 100, 044605 (2019).
S. Michimasa, J. Hwang, K. Yamada, H. Otsu et al., “OEDO, the energy-degrading beamline at RI Beam Factory,” Prog. Theor. Exp.
Phys. 4, 043D01 (2019).
J. Hwang, S. Michimasa, S. Ota, H. Otsu et al., “Angle-tunable wedge degrader for an energy-degrading RI beamline,” Prog. Theor. Exp.
Phys. 4, 043D02 (2019).
S. Takeuchi, T. Nakamura, M. Shikata, H. Otsu et al., “Coulomb breakup reactions of 93, 94 Zr in inverse kinematics,” Prog. Theor. Exp.
Phys. 1, 013D02 (2019).

[Proceedings]
X. Sun, H. Wang, H. Otsu, H. Sakurai et al., “Cross section measurements in the reactions of 136 Xe on proton, deuteron and carbon
at 168 MeV/u,” Proc. of the 15th Internat. Conf. on Nuclear Reaction Mechanisms, CERN-Proceedings-2019-001 (CERN, Geneva,2019), pp. 153–157.
Yu. Watanabe, J. Suwa, K. Nakano, H. Otsu et al., “Isotopic production cross sections of residual nuclei in proton- and deuteron-induced
reactions on 91, 92 Y, 92, 93 Zr, and 93, 94 Nb around 100 MeV/nucleon,” Proc. of the 15th Internat. Conf. on Nuclear Reaction Mechanisms,
CERN-Proceedings-2019-001 (CERN, Geneva, 2019), pp. 139–144.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Presentations[International conferences/workshops]
H. Otsu, “Cross section measurements for LLFP nuclei at RIBF,” Fourth International Workshop on Technology and Components ofAccelerator-Driven Systems (TCADS-4), Antwerp, Belgium, October 14–16, 2019.
H. Wang, “Spallation reaction study for long-lived fission products in nuclear waste,” International Nuclear Physics Conference 2019
(INPC2019), Glasgow, UK, July 29–August 2, 2019.
H. Wang, “Spallation reaction study for long-lived fission products in nuclear waste,” International conference on nuclear data andtechnology (ND2019), Beijing, China, May 19–24, 2019.
K. Nakano, “Isotope-production Cross Sections of Residual Nuclei in Proton- and Deuteron-induced Reactions on 93 Zr at 50 MeV/u,”International conference on nuclear data and technology (ND2019), Beijing, China, May 19–24, 2019.
X. Sun, “Cross-section Measurement in the Reactions of 136 Xe on Proton, Deuteron and Carbon,” International conference on nuclear
data and technology (ND2019), Beijing, China, May 19–24, 2019
Y. Togano et al., “Status report of dipole strength measurement performed in S09 and ImPACT,” SAMURAI International Collaboration
Workshop, Rikkyo University, Japan, August 30–31, 2019.

[Domestic conferences/workshops]େ௡ल‫ ڿ‬ଞ 4 ໊, ImPACT-RIBF Collaboration, ʮ֩ม‫ʹ׵‬ΑΔߴϨϕϧ์ࣹੑഇ‫غ‬෺ͷେ෯ͳ௿‫ݮ‬ɾࢿ‫ݯ‬Խ (4-1), “LLFP ͷஅ໘ੵଌఆͱͦͷΤωϧΪʔґଘੑ”ʯ, ೔ຊ‫ֶྗࢠݪ‬ձ, ਫ‫ށ‬, 2019 ೥ 3 ݄.

Press releasesϫϯɾϔ (Wang He), େ௡ल‫ڿ‬, ᓎҪതّ, ʮॏཅࢠʹΑΔ‫ݩ‬ૉม‫཰֬׵‬ͷ૿େ—ͦͷ··༥߹͢Δ͔, ෼྾͔ͯ͠ΒҰ෦͚ͩ༥߹
͢Δ͔—ʯ, ཧԽֶ‫ॴڀݚ‬, 2019 ೥ 7 ݄ 5 ೔.

Doctor thesesத໺‫ܟ‬ଠ, “Study of Isotope Production in Proton- and Deuteron-Induced Spallation Reactions on 93 Nb and 93 Zr,” ‫۝‬भେֶ େֶӃ૯߹ཧ޻ֶ෎.

Bachelor thesesদଜཧ‫ٱ‬, ʮ֩෼྾ੜ੒֩छ 90 Sr ͷཅࢠ͓Αͼॏཅࢠ༠‫ى‬൓Ԡʹؔ͢Δ‫ڀݚ‬ʯ, ౦๜େֶ ཧֶ෦.
੢௡ඒ࡙, ʮSe-79 ͷ֩ഁࡅ൓Ԡσʔλऔಘʹ޲͚ͨೋ࣍ϏʔϜͷཻࢠࣝผʯ, ‫۝‬भେֶ ૯߹ཧ޻ֶ෦.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Nuclear Transmutation Data Research Group
Slow RI Data Team
1. Abstract

This team is in charge of the development of low-energy RI beams of long-lived fission fragments (LLFP) from the 238 U by meansof degrading the energy of beams produced by the BigRIPS fragment separator.

2. Major Research Subjects
Studies of the slowing down and purification of RI beams are the main subjects of the team. Developments of devices used forthe slowing down of RI beams are also an important subject.
(1) Study and development of the slowed-down methods for LLFP.
(2) Development of the devices used for the slowing down.
(3) Operation of the BigRIPS separator and supply the low energy LLFP beam to the experiment in which the cross sections of
LLFP are measured at the low energy.
(4) Development of the framework to seamlessly handle device, detector, DAQ, and analysis for the easy control of the complicate
slowed-down RI beam production and its development.

3. Summary of Research Activity
A new OEDO beam line, designed for the slowed-down RI beams, was constructed under the collaboration with CNS, the University of Tokyo. Our group was responsible for the construction of the infrastructure such as the cooling water and the electricalequipment, and the movement and alignment of existing vacuum chambers, quadrupole magnets. The power supply for the Superconducting Triplet Quadrupoles (STQ) was made, which had a stability also under the low current condition.
Slowed-down 93 Zr beams with 20 or 50 MeV/nucleon were successfully developed at June 2016 for the first time. The methods
to obtain the narrow energy, position, and angle distribution were developed. The methods of the energy adjustment and the particle
identification at 50 MeV/nucleon were developed. The 93 Zr and 107 Pd beams with 50 MeV/nucleon were produced for the nucleartransmutation experiments using proton or deuteron targets at October 2016. The commissioning experiment of the OEDO beam line
was successfully performed at June 2017. The first transmutation experiments using OEDO beam line were performed with 93 Zr,
107
Pd, and 79 Se around 20 MeV/nucleon.
With our developments, the slowed-down RI beams became ready for the transmutation experiments. On the other hand, theprocedure to make the slowed-down RI beams became highly specialized. In order to easily produce the slowed-down RI beam, theframework is under the development to seamlessly handle the device, detector, DAQ, and analysis.

Members
Team Leader
Toshiyuki SUMIKAMA
Student Trainee
SungHan BAE (Seoul Nat’l Univ.)

List of Publications & Presentations
Publications[Original papers]
S. Takeuchi et al., “Coulomb breakup reactions of 93, 94 Zr in inverse kinematics,” Prog. Theor. Exp. Phys. 2019, 013D02 (2019).
S. Michimasa et al., “OEDO, the energy degrading beamline at RI Beam Factory,” Prog. Theor. Exp. Phys. 2019, 043D01 (2019).
H. Jongwon et al., “Angle-tunable wedge degrader for an energy-degrading RI beamline,” Prog. Theor. Exp. Phys. 2019, 043D02 (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
Nuclear Transmutation Data Research Group
Muon Data Team
1. Abstract

Dr. Yoshio Nishina observed muons in cosmic rays in 1937. The muon is an elementary particle similar to electron and classified
to lepton group. The muon has positive or negative electric charge, and the lifetime is 2.2 µsec. The negative muon (µ− ) is 207 times
heavier than the electron and behaves as a “heavy electron” in materials. The negative muon is captured by atomic orbits of nuclei toform a muonic atom and cascades down to the 1 s orbit to make muon nuclear capture. The muon is combined with a proton in the
nucleus to convert to a neutron and a neutrino. The muon nuclear capture reaction on a nucleus (ZA N) with the atomic number Z andmass number A generates the isotopes of ZA––1x N (x = 0, 1, 2, 3, 4) by emitting some neutrons in the reaction. The phenomenon is called“muon nuclear transmutation.” The reaction branching ratio of ZA N(µ− , xnν)ZA––1x N reactions (x = 0, 1, 2, 3, 4) is one of importantfactors toward various applications with nuclear transmutation technique. From a viewpoint of the nuclear physic, the muon nuclear
capture reaction is very unique and interesting. A high-energy compound nuclear state is suddenly generated in the nuclei associatedwith a weak conversion process of proton to neutron and neutrino. Many experimental results have been so far reported, however, thereaction mechanism itself is not well clarified. The research team aims at obtaining the experimental data to investigate the reaction
mechanism of muon nuclear capture, and also at theoretical understanding on the nuclear capture reaction.

2. Major Research Subjects(1) Experimental clarification on the mechanism of nuclear muon capture reaction(2) Theoretical understanding on the nuclear muon capture reaction(3) Interdisciplinary applications with the nuclear transmutation technique

3. Summary of Research Activity

There are two experimental methods to study the muon nuclear capture reaction. The first one is “muon in-beam spectroscopy
method.” The neutron and γ-ray emissions from the excited states of ZA––1x N nuclei are prompt events and are observed by the “muonin-beam spectroscopy method” with a DC muon beam. The reaction branching ratio is directly determined by measuring the neutron
multiplicity in the reaction. The DC muon beam is available at the MuSIC (Muon Science Innovative Channel) muon facility in the
Research Center for Nuclear Physics (RCNP) at Osaka University. The second one is “muon activation method” with the pulsed
muon beam. The produced unstable nuclei ZA––1x N make β+/− decays. The γ-rays associated with β+/− decays to the daughter nuclei areobserved in the experiment. The build-up curve of γ-ray yield at muon beam-on and the decay curve at beam-oﬀ are measured. Since
the half-lives and decay branching ratios of β+/− -γ decays are known, the reaction branching ratios to the ZA––1x N nuclei are determinedby the γ-ray yield curves. The pulsed muon beam is available at the RIKEN-RAL Muon Facility in the UK and J-PARC muon facility.
Muon nuclear capture reactions are studied on five isotope-enriched palladium targets (104, 105, 106, 108, 110 Pd) and five isotopeenriched zirconium targets (90, 91, 92, 94, 96 Zr) employing two experimental methods. By obtaining the experimental data on the Pd and Zr
targets, the reaction mechanism is investigated experimentally, and the results are compared with appropriate theoretical calculations.
The 107 Pd is classified to a long-lived fission product (LLFP) and is contained in a spent nuclear fuel. The study of muon nuclear
capture on the Pd and Zr targets is aiming at exploring a possible reaction path to make the nuclear transmutation of the Pd and Zr
metal extracted from the spent nuclear fuel without an isotope separation process. This research was funded by the ImPACT Programof Council for Science, Technology and Innovation (Cabinet Oﬃce, Government of Japan).
(1) Experiments with “muon in-beam spectroscopy method”
Muon nuclear capture reactions were investigated on five palladium targets (104, 105, 106, 108, 110 Pd) by employing the DC muon
beam at MuSIC. The γ-ray and neutron in the muon nuclear capture reaction were measured with the time information relative toA
A– xPd(µ− , xnν)45
Rh reactions, wheremuon beam arrival. The measured neutron multiplicity gives the reaction branching ratio of 46
A = 104, 105, 106, 108, 110 and x = 0, 1, 2, 3, 4.
Employing a newly built neutron spectrometer, the neutron was measured to obtain the reaction branching ratios of muon capture
reactions on the Pd targets. We have constructed a neutron spectrometer named “Seamine”: Scintillator Enclosure Array for Muon
Induced Neutron Emission. The spectrometer consists of 21 liquid scintillation counters, 2 Ge γ-ray detectors, 7 BaF2 counters. The
Pd target, muon beam counters and muon degraders are placed at the center of spectrometer. The neutron counter is a BC-501A
liquid scintillation counter with 20 cm diameter and 5 cm depth and is connected to a 5” photo multiplication tube (H4144-01). The
total neuron detection eﬃciency is estimated 5%, where the distance is 4 cm from the target to neutron counters. The Ge γ-ray
detectors are placed at 10 cm form the target, and the typical detection eﬃciency is 0.5% for 200 keV γ-ray. The BaF2 counters arelocated beneath the target to detect fast γ-rays emitted from the compound nucleus formed in the reactions. Signals from the liquid
scintillation counters are processed in a CAEN V1730B waveform digitizer (16 channel, 14 bit, 500 M samplings/sec.). The neuron-γ
discrimination is performed on-line during the experiment, and the detailed data analysis is conducted oﬀ-line after the experiment.
The neutron energy spectrum is constructed in the digitizer. Signals from Ge detectors are also processed in the digitizer to obtain theenergy and time spectrum of γ-rays associated with the reaction. Signals from the BaF2 counters and muon beam counters are sent to
the digitizer to make the fast timing signals.
We have established the muon in-beam spectroscopy method employing the “Seamine” spectrometer. The neutron data analysis- 290 -

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is in progress to obtain the multiplicity, the energy and the TOF spectrum using start signals given by γ-rays detected in the BaF2
counters. The γ-ray data gives the energy spectrum of prompt γ-rays and muonic X-rays originated from the 104, 105, 106, 108, 110 Pdtargets.
(2) Experiments with “muon activation method” at the RIKEN-RAL Muon Facility
We conducted the experiments on the muon nuclear capture employing the muon activation method at the RIKEN-RAL Muon
Facility in the UK. The pulsed muon beam was irradiated on the 104, 105, 106, 108, 110 Pd targets. The γ-rays were detected by a Ge detector
located at the downstream of the Pd targets to maximize the detection eﬃciency. The build-up and decay curves of γ-ray intensities
were measured associated with β+/− decays of produced unstable nuclei to daughter nuclei. The γ-ray-yield curves give the absoluteAA– xPd(µ− , xnν)45
Rh reactions. The
radiation activity produced by the reaction, and the reaction branching ratios are determined for 46
decay curves of γ-rays from the produced nuclei with long half-lives were measured under low γ-ray background at an experimental
apparatus built in a separated room. The detailed oﬀ-line data analysis is in progress.
(3) Experiments with “muon activation method” at J-PARC muon facility
The experiments employing the muon activation method were performed at J-PARC muon facility. The five isotope-enriched Pdtargets (104, 105, 106, 108, 110 Pd) were irradiated by the pulsed muon beam, and the build-up and decay curves of γ-ray intensities were
measured.
In addition to the Pd targets, the experiments on five isotope-enriched Zr target (90, 91, 92, 94, 96 Zr) were conducted to obtain theA
A– xZr(µ− , xnν)39
Y reactions, where A = 90, 91, 92, 94, 96. The obtained reaction branching ratios on thereaction branching ratios of 40
Pd and Zr targets are important to understand the reaction mechanism of muon nuclear capture. The 93 Zr is one of the LLFP and iscontained in a spent nuclear fuel. The experiment on the Zr targets is to explore a possibility to realize the nuclear transmutation of
the Zr metal extracted from the spent nuclear fuel.
−107– xIn order to obtain the reaction branching ratio of 107
46 Pd(µ , xnν)45 Rh reactions, the muon activation experiment was performed
employing a Pd target containing 107 Pd of 15.3%. The γ-ray intensities associated with β+/− decays of produced unstable nuclei were
measured to obtain the build-up and decay curves. Once the branching ratios of the reactions on the 104, 105, 106, 108, 110 Pd targets are
obtained, these contributions are extracted from the branching-ratio data obtained for the Pd target with 107 Pd. The reaction branching−
107– xratio of 107
46 Pd(µ , xnν)45 Rh reactions is finally determined. The detailed oﬀ-line data analysis is in progress.
(4) Comparison with theory
The muon activation method gives the reaction branching ratios. The muon in-beam spectroscopy method gives the neutron
multiplicity and the neutron energy spectrum. These experimental results are important to understand the compound nuclear state andneutron emission mechanism. The reaction branching ratios obtained by the muon activation method are compared with the results ofneutron multiplicity measurements. The neutron energy spectrum is considered to be reflected by the energy distribution of compound
nuclear state and neutron emission mechanism. The experimental results are compared with the appropriate calculations employing theneutron emission mechanisms due to an evaporation, a cascade and a direct emission processes with assuming the energy distribution
at compound nuclear state.

Members
Team Leader
Hiroyoshi SAKURAI
Contract Researcher
Teiichiro MATSUZAKI

List of Publications & Presentations
Publications[Original papers]
S. Wenner, C. D. Marioara, K. Nishimura, K. Matsuda, S. Lee, T. Namiki, I. Watanabe, T. Matsuzaki, and R. Holmestad, “Muon spin
relaxation study of solute?vacancy interactions during natural aging of Al-Mg-Si-Cu alloys,” Metall. Mater. Trans. A 50, 3446–3451(2019).

[Proceedings]
R. Fujita, M. Kawashima, M. Ozawa, and T. Matsuzaki, “Reduction and resource recycling of high-level radioactive wastes throughnuclear transmutation—overview and current progress—,” Proceeding for the 13th International Conference on Nucleus-Nucleus Collisions (NN2018).

Presentations[International conferences/workshops]
T. Saito, M. Niikura, T. Matsuzaki, and H. Sakurai for ImPACT muon collaboration, “Neutron emission property after nuclear muon
capture of palladium,” International Nuclear Physics Conference 2019, Scottish Event Campus, Glasgow, UK, July 29–August 2, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
High-Intensity Accelerator R&D Group
1. Abstract
The High-Intensity Accelerator R&D group, consisting of two teams, develops elemental technology of high-power acceleratorsand high-power targets, aiming at future applications to nuclear transmutations of long-lived fission product into short-lived nuclides.
The research subjects are superconducting rf cavities for low-velocity ions, design of high-power accelerators, high-power target
systems and related technologies.
Nuclear transmutation with high-intensity accelerators is expected to reduce the high-level radioactive wastes and to recycle
the precious resources such as rare-earth materials in future. This method is one of the important applications of the ion-accelerator
technologies that have been developed at RIKEN for a long time. Under the framework of ImPACT Fujita Program, we have conducted
R&D of elemental technology related to the high-power accelerators and high-power targets, from FY2014 to FY2018. We gained alot of experiences in these R&Ds. Among them, the development of a superconducting rf cavity has become the basis of the upgrade
program of the RILAC facility which started in 2016.

2. Major Research Subjects(1) R&D of elemental technology of high-power accelerators and high-power targets.

3. Summary of Research Activity(1) A high-gradient rf cavity has been constructed and tested based on the superconducting rf technology.
(2) Several candidates for the high-power target have been proposed and their prototypes have been tested.
(3) A high-current deuteron RFQ has been designed.

MemberGroup Director
Osamu KAMIGAITO (concurrent: Group Director, Accelerator Group)- 292 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
High-Intensity Accelerator R&D Group
High-Gradient Cavity R&D Team
1. Abstract

We develop new components for accelerators dedicated for low-beta-ions with very high intensity. Specifically, we are designingand constructing a cryomodule for superconducting linac eﬃcient for acceleration of low-beta-ions. In parallel, we try to optimize an
rf acceleration system by making computer simulations for acceleration of very high intensity beams.

2. Major Research Subjects(1) Development of high-gradient cavites for low beta ions
(2) Development of power saving cryomodules

3. Summary of Research Activity• Development of highly eﬃcient superconducting accelerator modules

Members
Team Leader
Naruhiko SAKAMOTO
Research/Technical Scientists
Kazunari YAMADA
Yutaka WATANABE

Kazutaka OZEKI

Research & Development Scientist
Kenji SUDA

List of Publications & Presentations
Publications[Proceedings]
N. Sakamoto, T. Dantsuka, M. Fujimaki, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, K. Suda, A. Uchiyama, T. Watanabe,
Y. Watanabe, K. Yamada, E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara, A. Miyamoto, K. Sennyu, and T. Yanagisawa, “Development of superconducting quarter-wave resonator and cryomodule for low-beta ion accelerators at RIKEN Radioactive Isotope Beam
Factory,” Proceedings of the 19th International Conference on RF Superconductivity (SRF2019), (2019), pp. 750–757.

Presentations[International conferences/workshops]
N. Sakamoto, T. Dantsuka, M. Fujimaki, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, K. Suda, A. Uchiyama, T. Watanabe,
Y. Watanabe, K. Yamada, E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara, A. Miyamoto, K. Sennyu, and T. Yanagisawa (invited),“Development of superconducting quarter-wave resonator and cryomodule for low-beta ion accelerators at RIKEN Radioactive Isotope
Beam Factory,” 19th International Conference on RF Superconductivity (SRF2019), Dresden, Germany, June 30–July 5, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Nuclear Science and Transmutation Research Division
High-Intensity Accelerator R&D Group
High-Power Target R&D Team
1. Abstract

The subjects of this team cover R&D studies with respect to target technology for the transmutation of the LLFPs.

2. Major Research Subjects(1) Liquid lithium target for production of neutron or muon
(2) Beam window without solid structure

3. Summary of Research Activity(1) Liquid lithium target for production of neutron or muon
(H. Okuno)(2) Beam window with solid structure(H. Okuno)

MemberTeam Leader
Hiroki OKUNO

List of Publications & Presentations
Publications[Original papers]
H. Okuno, H. Sakurai, Y. Mori, R. Fujita, and M. Kawashima, “Proposal of a 1-ampere-class deuteron single-cell linac for nuclear
transmutation,” Proceedings of the Japan Academy, Series B 95, 430–439 (2019).

Presentations[International conferences/workshops]
H. Okuno (oral), “Accelerator and target for transmutation of long-lived fission products in nuclear waste,” Fourth International Workshop
on Technology and Components of Accelerator-Driven Systems (TCADS-4), Antwerp, Belgium, October 14–17, 2019.
H. Okuno (oral), “Seeking for a novel fabrication technology to make a large-bore SRF-QWR cavity for 1-ampere class linac,” TTC 2020,
Genève, Switzerland, February 4–7, 2020.

Press releasesʮʮ֩ͷΰϛʯ໰୊ղܾʹඞཁͳՃ଎‫ث‬ͷ֓೦ΛఏҊ—‫ط‬ଘͷ 300 ഒͷߴग़ྗॏཅࢠϏʔϜͷՃ଎͕Մೳʹ—ʯ, ཧ‫ݚ‬ϓϨεϦϦʔε, 2019 ೥ 8 ݄ 9 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Accelerator Group
1. Abstract

The Accelerator Group, consisting of seven teams, pursues various upgrade programs on the world-leading heavy-ion accelerator
facility, RI Beam Factory (RIBF), to enhance the accelerator performance and operation eﬃciency. The programs include the R&D
of superconducting ECR ion source, charge stripping systems, beam diagnostic devices, radiofrequency systems, control systems, andbeam simulation studies. We are also maintaining the large infrastructure to realize eﬀective operation of the RIBF. Moreover, we are
actively promoting the applications of the facility to various research fields.
Our primary mission is to supply intense, stable heavy-ion beams for the users through eﬀective operation, maintenance, andupgrade of the RIBF accelerators and related infrastructure. The director members govern the development programs that are not dealt
with by a single team, such as intensity upgrade and eﬀective operation. We also discuss the future plans of RIBF along with otherlaboratories belonging to the RIBF research division.
Various improvements and developments have been carried out for the RIBF accelerators in order to upgrade the beam intensities
and stability. Owing to the eﬀorts, for example, the intensity of the uranium beam has increased by 70% in the last three years, resulting
in the intensity of 94 pnA (7.7 kW) at the exit of the superconducting ring cyclotron. The beam intensity of 124 Xe has increased to
173 pnA, corresponding to the beam power of 7.4 kW.
In 2016, a supplemental budget was approved for the upgrade of RIBF aiming at synthesizing heavier new elements. A superconducting linac booster has been constructed at the RILAC facility with this budget under the collaboration with KEK researchers.
We also constructed a new superconducting ECR ion source at RILAC. The beam commissioning with the upgraded RILAC, which
has been named “SRILAC,” was started in January 2020. Finally, the SRILAC facility passed the facility inspection by the Nuclear
Regulatory Authority on the last day of FY2019. The accelerating cavities of the ring cyclotron, which had been suﬀered from thelow accelerating voltage, were also modified with this supplemantal budget. This modification played a key role in the increase of thebeam intensities of uranium and xenon mentioned above. We also started providing intense vanadium beams for the synthesis of a
new element [119] at GARIS II in 2017.
On the other hand, we have started a new project with RCNP, Osaka university, for the promotion of application research using
short-lived radioisotopes since 2017. A high-power target for production of 211 At is under development with RI Application ResearchGroup of RNC in the framework of this project. It will be installed and tested in the SRILAC facility in near future.
An upgrade plan of RIBF for further increasing heavy-ion beams, especially the uranium beam, has been continuously discussed.
The plan proposed recently is based on a new idea of “charge-stripper ring (CSR),” which is used to improve the overall stripping
eﬃciency of the uranium beam. This device recirculates and re-injects the uranium ions into the charge stripper until the ions become
the charge state required for the succeeding acceleration, while the bunch structure is kept with its isometric orbit lengths for all the
charge states. Design study of the whole CSR is under progress after intensive optical calculations for the circulating beam. The final
goal of this plan is to increase the uranium beam intensity by 20 times of the present value, namely up to 2000 pnA, at the exit of SRC.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Intensity upgrade of RIBF accelerators (Okuno)
Eﬀective and stable operation of RIBF accelerators (Fukunishi)
Commissioning of the upgraded RILAC (SRILAC) facility
Promotion of the future plan

3. Summary of Research Activity(1) The maximum intensities of the uranium and xenon beams reached 94 and 173 pnA, respectively, at 345 MeV/nucleon.
(2) The maximum intensity of the calcium beam reached 740 pnA at 345 MeV/nucleon, which corresponds to 12.3 kW. That of
the krypton beam reached 486 pnA, corresponding to 13.4 kW.
(3) The overall beam availability for the RIBF experiments averaged for 5 years from 2013 to 2017 was 92%. Although theavailability fell down to 79% in 2018 because of several hardware troubles, it exceeded 92% in 2019.
(4) A major upgrade of the accelerator facility has been conducted aiming at synthesizing heavier new elements. It includes
construction of a superconducting linac booster of RILAC, construction of a new superconducting ECR ion source, andmodification of the accelerating cavities of the ring cyclotron (RRC). The upgraded RILAC (SRILAC) facility passed thefacility inspection by the Nuclear Regulatory Authority, as scheduled.
(5) The large infrastructure was properly maintained based on a well-organized cooperation among the related sections.
(6) An intensity-upgrade plan of the RIBF has been further investigated. Design study of the charge-stripper ring (CSR) is underprogress.

Members
Group Director- 295 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Osamu KAMIGAITO
Deputy Group Directors
Hiroki OKUNO (for intensity upgrade)

Nobuhisa FUKUNISHI (for stable and eﬃcient operation)

Junior Research Associate
Takahiro KARINO (Utsunomiya Univ.)

Kaori NAKAMURA (The University of Tokyo)

Research Part-time Worker I
Akira GOTO

Masayuki KASE

Research Consultants
Tadashi FUJINAWA

Toshiyuki HATTORI

Visiting Scientists
Eiji KAKO (KEK)
Hirotaka NAKAI (KEK)
Kensei UMEMORI (KEK)
Hiroshi SAKAI (KEK)

Taro KONOMI (KEK)
Noboru SASAO (Okayama Univ.)
Yasutaka IMAI (Okayama Univ.)

Student Trainees
Akira FUJIEDA (Okayama Univ.)

Hiroyuki KAINO (Okayama Univ.)

Assistant
Karen SAKUMA
Administrative Part-time Worker II
Ryoko UMEZAKI

List of Publications & Presentations
Publications[Original papers]
T. Karino, “Evaluation method of beam instability in laser ion source using solenoid,” Rev. Sci. Instrum. 91, 033316 (2020).
K. Nakamura, N. Nishiura, M. Okamura, T. Kanesue, S. Ikeda, and A. Cannavo, “Feasibility study of a compact heavy ion source forinvestigation of laboratory magnetospheric plasma,” Rev. Sci. Instrum. 91, 033503 (2020).

[Proceedings]
O. Kamigaito, K. Ozeki, N. Sakamoto, K. Suda, and K. Yamada, “Measurement of mechanical vibration of SRILAC cavities,” Proceedingsof the 19th International Conference on RF Superconductivity (SRF2019), (Dresden, Germany, TUP042, 2019), pp. 515.
O. Kamigaito, T. Dantsuka, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, M. Kidera, M. Komiyama, K.
Kumagai, T. Maie, Y. Miyake, T. Nagatomo, T. Nakagawa, M. Nakamura, T. Nishi, J. Ohnishi, H. Okuno, K. Ozeki, N. Sakamoto, K.
Suda, A. Uchiyama, T. Watanabe, Y. Watanabe, and K. Yamada, “Recent progress in RIKEN RI Beam Factory,” Proceedings of 22ndInternational Conference on Cyclotrons and their Applications (CYC2019), (Cape Town, South Africa, MOB01, 2019).

Presentations[International conferences/workshops]
O. Kamigaito (invited), “Recent progress in RIKEN RI Beam Factory,” 22nd International Conference on Cyclotrons and their Applications (CYC2019), Cape Town, South Africa, September 22–27, 2019.
T. Karino (oral), “Evaluation method of beam instability in laser ion source using solenoid,” The 18th International Conference on Ion
Sources (ICIS2019), Lanzhou, China, September 1–6, 2019.
K. Nakamura (oral), “Feasibility study of a compact heavy ion source for investigation of laboratory magnetospheric plasma,” The 18th
International Conference on Ion Sources (ICIS2019), Lanzhou, China, September 1–6, 2019.
A. Fujieda (oral), “Ba-ion spectroscopy experiment for high-intensity gamma-ray source using heavy ions,” The 12th International Workshop on Fundamental Physics Using Atoms (FPUA2020), Wako, Japan, January 9–10, 2020.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Accelerator Group
Accelerator R&D Team
1. Abstract
We are developing the key hardware in upgrading the RIBF accelerator complex. Our primary focus and research is charge
stripper which plays an essential role in the RIBF accelerator complex. Charge strippers remove many electrons in ions and realizeeﬃcient acceleration of heavy ions by greatly enhancing charge state. The intensity of uranium beams is limited by the lifetime of the
carbon foil stripper conventionally installed in the acceleration chain. The improvement of stripper lifetimes is essential to increase
beam power towards the final goal of RIBF in the future. We are developing the low-Z gas stripper. In general gas stripper is free fromthe lifetime related problems but gives low equilibrium charge state because of the lack of density eﬀect. Low-Z gas stripper, however,can give as high equilibrium charge state as that in carbon foil because of the suppression of the electron capture process. Another our
focus is the upgrade of the world’s first superconducting ring cyclotron.

2. Major Research Subjects(1) Development of charge strippers for high power beams (foil, low-Z gas)
(2) Upgrade of the superconducting ring cyclotron(3) Maintenance and R&D of the electrostatic deflection/inflection channels for the beam extraction/injection

3. Summary of Research Activity(1) Development of charge strippers for high power beams (foil, low-Z gas)
(H. Hasebe, H. Imao, H. Okuno)
We are developing the charge strippers for high intensity heavy ion beams. We are focusing on the developments on carbon or
berrilium foils and gas strippers including He gas stripper.
(2) Upgrade of the superconducting ring cyclotron(J. Ohnishi, H. Okuno)
We are focusing on the upgrade of the superconducting ring cyclotron.
(3) Maintenance and R&D of the electrostatic deflection/inflection channels for the beam extraction/injection(J. Ohnishi, H. Okuno)
We are developing high-performance electrostatic channels for high power beam injection and extraction.

Members
Team Leader
Hiroki OKUNO
Research/Technical Scientists
Hiroshi IMAO (Senior Research Scientist)
Jun-ichi OHNISHI (Senior Technical Scientist)

Hiroo HASEBE (Technical Scientist)

Special Postdoctoral Researcher
Yasuto MIYAKE
Junior Research Associate
Naoya IKOMA
Visiting Scientists
Andreas ADELMANN (Paul Sherrer Inst.)
Noriyosu HAYASHIZAKI (Tokyo Tech)

Hironori KUBOKI (KEK)

Student Trainees
Taishi SASAKI (Nagaoka Univ. of Tech.)

Yoshiki SHIKUMA (Nagaoka Univ. of Tech.)Part-time Workers
Taishi SASAKI (Research Part-time Worker II)

Yoshiki SHIKUMA (Research Part-time Worker II)- 297 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Original papers]
N. Ikoma, Y. Miyake, M. Takahashi, H. Okuno, S. Namba, K. Takahashi, T. Sasaki, and T. Kikuchi, “Demonstration of plasma window
with diameter of 20 mm and pressure separation for accelerator application,” Plasma Fusion Res. 14, 1206148 (2019).
N. Ikoma, Y. Miyake, M. Takahashi, H. Okuno, S. Namba, K. Takahashi, T. Sasaki, and T. Kikuchi, “Characteristics of plasma window
with various channel diameters for accelerator applications,” Review of Scientific Instruments 91, 053503 (2020).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Accelerator GroupIon Source Team
1. Abstract
Our aim is to operate and develop the ECR ion sources for the accelerator-complex system of the RI Beam Factory. We focus on
further upgrading the performance of the RI Beam Factory through the design and fabrication of a superconducting ECR ion sourcefor production of high-intensity heavy ions.

2. Major Research Subjects(1) Operation and development of the ECR ion sources(2) Development of a superconducting ECR heavy-ion source for production of high-intensity heavy ion beams

3. Summary of Research Activity(1) Operation and development of ECR ion sources(T. Nakagawa, M. Kidera, Y. Higurashi, T. Nagatomo, Y. Kanai, and H. Haba)
We routinely produce and supply various kinds of heavy ions such as zinc and calcium ions for the super-heavy element searchexperiment as well as uranium ions for RIBF experiments. We also perform R&D’s to meet the requirements for stable supply ofhigh-intensity heavy ion beams.
(2) Development of a superconducting ECR ion source for use in production of a high-intensity heavy ion beam
(T. Nakagawa, J. Ohnishi, M. Kidera, Y. Higurashi, and T. Nagatomo)
The RIBF is required to supply heavy ion beams with very high intensity so as to produce RI’s and for super-heavy element searchexperiment. We have designed and are fabricating an ECR ion source with high magnetic field and high microwave- frequency, since
the existing ECR ion sources have their limits in beam intensity. The coils of this ion source are designed to be superconducting for the
production of high magnetic field. We are also designing the low-energy beam transport line of the superconducting ECR ion source.

Members
Team Leader
Takahide NAKAGAWA
Research/Technical Scientists
Takashi NAGATOMO (Senior Technical Scientist)
Yoshihide HIGURASHI (Technical Scientist)

Masanori KIDERA (Technical Scientist)

Special Temporary Research Scientist
Yasuyuki KANAI

List of Publications & Presentations
Publications[Original papers]
T. Nagatomo et al., “High intensity vanadium beam for synthesis of new superheavy elements with well-controlled emittance by using“slit triplet”,” Rev. Sci. Instrum. ICIS18, 023318 (2020).
A. Uchiyama et al., “Control system for the new RIKEN 28-GHz superconducting electron cyclotron resonance ion source for SRILAC,”
Rev. Sci. Instrum. ICIS18, 025101 (2020).

[Proceedings]
T. Nagatomo et al., “Development of RIKEN 28 GHz SC-ECRISs for synthesizing super-heavy elements,” Proc. HIAT2018,
doi:10.18429/JACoW-HIAT2018-TUZAA01.

Presentations[International conferences/workshops]
Y. Higurashi (invited), “Status and perspective for high intensity uranium beams from the RIKEN 28 GHz ECRIS,” ICIS2019, Lanzhou,
China, September 1–6, 2019.
T. Nakagawa (oral), “Production of intense metal ion beam with RIKEN 28 GHz SC-ECRIS,” ICIS2019, Lanzhou, China, September
1–6, 2019.
T. Nagatomo (oral), “Well-controlled emittance of the metallic ion beam extracted from the 28 GHz SC-ECRIS adopting the super
conducting acceleration cavity for new super heavy elements research,” ICIS2019, Lanzhou, China, September 1–6, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Accelerator GroupRILAC Team
1. Abstract

The operation and maintenance of the RIKEN Heavy-ion Linac (RILAC) have been carried out. There are two operation modes:
one is the stand-alone mode operation and the other is the injection mode operation. The RILAC has been used especially as an
injector for the RIKEN RI- Beam Factory accelerator complex. The RILAC is composed of the 28 GHz SC ECR ion source, thefrequency-variable RFQ linac, the frequency-variable main linac, and the SC booster linac (SRILAC).

2. Major Research Subjects(1) The long term high stability of the RILAC operation.
(2) Improvement of high eﬃciency of the RILAC operation.

3. Summary of Research Activity

The RILAC was started to supply ion beams for experiments in 1981. Thousands hours are spent in a year for delivering manykinds of heavy-ion beams to various experiments.
The RILAC has two operation modes: one is the stand-alone mode operation delivering low-energy beams directly to experiments
and the other is the injection mode operation injecting beams into the RRC. In the first mode, the RILAC supplies a very important
beam to the nuclear physics experiment of “the research of super heavy elements.” In the second mode, the RILAC plays a very
important role as upstream end of the RIBF accelerator complex.
The maintenance of these devices is extremely important in order to keep the log-term high stability and high eﬃciency of the
RILAC beams. Therefore, improvements are always carried out for the purpose of more stable and more eﬃcient operation.

Members
Team Leader
Eiji IKEZAWA
Research/Technical Scientist
Yutaka WATANABE (Senior Technical Scientist)

List of Publications & Presentations
Publications[Proceedings]
M. Tamura, E. Ikezawa, T. Ohki, H. Yamauchi, K. Oyamada, A. Yusa, K. Kaneko, Y. Watanabe, and O. Kamigaito, “Present status of
RILAC,” Proceedings of the 16th Annual Meeting of Particle Accelerator Society of Japan, (2019), pp. 1263.

Presentations[Domestic conferences]ాଜ‫࢙ڡ‬, ஑୔ӳೋ, େ໦ஐଇ, ࢁ಺‫ࢿܒ‬, খࢁా࿨޾, ༡ࠤཅ, ۚࢠ݈ଠ, ౉ᬒ༟, ্֞֎मҰ, ʢFSPI010ʣ, ʮཧ‫ݚ‬ॏΠΦϯϦχΞο
Ϋͷ‫ݱ‬ঢ়ใࠂʯ, ୈ 16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫౎ژ‬, 2019 ೥ 7 ݄ 31 ೔–8 ݄ 3 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Accelerator Group
Cyclotron Team
1. Abstract

Together with other teams of Nishina Center accelerator division, maintaining and improving the RIBF cyclotron complex. The
accelerator provides high intensity heavy ions. Our mission is to have stable operation of cyclotrons for high power beam operation.
Recently stabilization of the rf system is a key issue to provide 10 kW heavy ion beam.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

RF technology for Cyclotrons
Operation of RIBF cyclotron complex
Maintenance and improvement of RIBF cyclotrons
Single turn operation for polarized deuteron beams
Development of superconducting cavity

3. Summary of Research Activity• Development of the rf system for a reliable operation• Development of highly stabilized low level rf system• Development of superconducting cavity• Development of the intermediate-energy polarized deuteron beams.

Members
Team Leader
Naruhiko SAKAMOTO
Research/Technical Scientists
Kazutaka OZEKI (Senior Technical Scientist)

Kenji SUDA (Technical Scientist)

List of Publications & Presentations
Publications[Proceedings]
K. Suda, O. Kamigaito, K. Ozeki, N. Sakamoto, Y. Watanabe, K. Yamada, E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara,
A. Miyamoto, K. Sennyu, and T. Yanagisawa, “Fabrication and performance of superconducting quarter-wavelength resonators for
SRILAC,” Proceedings of the 19th International Conference on RF Superconductivity, (2019), pp. 182–187.
H. Imao, O. Kamigaito, N. Sakamoto, T. Watanabe, Y. Watanabe, K. Yamada, and K. Oyamada, “Non-evaporative getter-based diﬀerential
pumping system for SRILAC at RIBF,” Proceedings of the 19th International Conference on RF Superconductivity (2019), pp. 419–423.
K. Yamada, T. Dantsuka, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, T. Watanabe, Y. Watanabe,
E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara, A. Miyamoto, K. Sennyu, and T. Yanagisawa, “Construction of superconducting
linac booster for heavy-ion linac at RIKEN Nishina Center,” Proceedings of the 19th International Conference on RF Superconductivity,(2019), pp. 502–507.
O. Kamigaito, K. Ozeki, N. Sakamoto, K. Suda, and K. Yamada, “Measurement of mechanical vibration of SRILAC cavities,” Proceedingsof the 19th International Conference on RF Superconductivity (2019), pp. 513–517.
݄‫ݑډ‬ढ़, ෱ᖒ੟ࣇ, ᖛ஥੣, ੴ઒੝, খྛਗ਼ࢤ, খࢁ྄, ஥ଜ෢ࢤ, ੢ాູ, ੢ଜ੣, ࣲాॱᠳ, ໼෌Ұ৻, େؔ࿨‫و‬, ஈ௩஌ࢤ, ౻‫ר‬ਖ਼थ, ౻ೄխ, ෱੢ெঘ, ௕୩෦༟༤, ೔฻঵ӳ, ஑୔ӳೋ, ࠓඌߒ࢜, ্֞֎मҰ, ۚҪอ೭, Ճ੉ণ೭, ໦ࣉਖ਼‫ݑ‬, ࠐࢁඒ࡙, ‫۽‬୩‫ࢠܡ‬, ਅՈ෢࢜, ௕੉੣, ௕༑ܼ, த઒޹ल, தଜਔԻ, େ੢७Ұ, Ԟ໺޿थ, ࡔຊ੒඙, ਢా݈࢚, ಺ࢁ‫ڿ‬ਔ, ౉෦ल, ౉ᬒ‫؀‬, ౉ᬒ༟,ࢁాҰ੒, ࢁᖒलߦ, ʮཧ‫ ݚ‬RIBF ʹ͓͚ΔϦϯάαΠΫϩτϩϯͷӡసใࠂʯ, ୈ 16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫౎ژ‬େֶ٢ాΩϟϯύε, (‫౎ژ‬, 2019), pp.1193–1197.
ᖛ஥੣, ෱ᖒ੟ࣇ, ੴ઒੝, খྛਗ਼ࢤ, খࢁ྄, ஥ଜ෢ࢤ, ੢ాູ, ੢ଜ੣, ࣲాॱᠳ, ݄‫ݑډ‬ढ़, ໼෌Ұ৻, ۚࢠ݈ଠ, খࢁా࿨޾, ాଜ‫࢙ڡ‬, ༡ࠤཅ, ਢా݈࢚, ౻‫ר‬ਖ਼थ, ෱੢ெঘ, ‫ޙ‬౻জ, ௕୩෦༟༤, ೔฻঵ӳ, ࠓඌߒ࢜, Ճ੉ণ೭, ্֞֎मҰ, ໦ࣉਖ਼‫ݑ‬, ࠐࢁඒ࡙,‫۽‬୩‫ࢠܡ‬, ਅՈ෢࢜, ௕੉੣, ௕༑ܼ, த઒޹ल, େ੢७Ұ, Ԟ໺޿थ, େؔ࿨‫و‬, ࡔຊ੒඙, ಺ࢁ‫ڿ‬ਔ, ౉෦ल, ౉ᬒ‫؀‬, ౉ᬒ༟, ࢁాҰ੒, খߴ߁র, େ৓޾ޫ, ʮཧ‫ ݚ‬AVF αΠΫϩτϩϯӡసͷ‫ݱ‬ঢ়ใࠂʯ, ୈ 16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫౎ژ‬େֶ٢ాΩϟϯύε,(‫౎ژ‬, 2019), pp. 1224–1228.

Presentations[International conferences/workshops]
K. Ozeki (oral), “Power couplers for RIKEN superconducting QWR,” World Wide Fundamental Power Coupler meeting #5, Geneva,
Switzerland, June 25–26, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

K. Suda, O. Kamigaito, K. Ozeki, N. Sakamoto, Y. Watanabe, K. Yamada, E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara,
A. Miyamoto, K. Sennyu, and T. Yanagisawa (poster), “Fabrication and performance of superconducting quarter-wavelength resonators
for SRILAC,” 19th International Conference on RF Superconductivity (2019), Dresden, Gernany, June 30–July 5, 2019.
H. Imao, O. Kamigaito, N. Sakamoto, T. Watanabe, Y. Watanabe, K. Yamada, and K. Oyamada (poster), “Non-evaporative getter-based
diﬀerential pumping system for SRILAC at RIBF,” 19th International Conference on RF Superconductivity (2019), Dresden, Gernany,
June 30–July 5, 2019.
K. Yamada, T. Dantsuka, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, T. Watanabe, Y. Watanabe,
E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara, A. Miyamoto, K. Sennyu, and T. Yanagisawa (poster), “Construction of superconducting linac booster for heavy-ion linac at RIKEN Nishina Center,” 19th International Conference on RF Superconductivity (2019),
Dresden, Gernany, June 30–July 5, 2019.
O. Kamigaito, K. Ozeki, N. Sakamoto, K. Suda, and K. Yamada (poster), “Measurement of mechanical vibration of SRILAC cavities,”
19th International Conference on RF Superconductivity (2019), Dresden, Gernany, June 30–July 5, 2019.

[Domestic conferences/workshops]݄‫ݑډ‬ढ़, ෱ᖒ੟ࣇ, ᖛ஥੣, ੴ઒੝, খྛਗ਼ࢤ, খࢁ྄, ஥ଜ෢ࢤ, ੢ాູ, ੢ଜ੣, ࣲాॱᠳ, ໼෌Ұ৻, େؔ࿨‫و‬, ஈ௩஌ࢤ, ౻‫ר‬ਖ਼थ, ౻ೄխ, ෱੢ெঘ, ௕୩෦༟༤, ೔฻঵ӳ, ஑୔ӳೋ, ࠓඌߒ࢜, ্֞֎मҰ, ۚҪอ೭, Ճ੉ণ೭, ໦ࣉਖ਼‫ݑ‬, ࠐࢁඒ࡙, ‫۽‬୩‫ࢠܡ‬, ਅՈ෢࢜, ௕੉੣, ௕༑ܼ, த઒޹ल, தଜਔԻ, େ੢७Ұ, Ԟ໺޿थ, ࡔຊ੒඙, ਢా݈࢚, ಺ࢁ‫ڿ‬ਔ, ౉෦ल, ౉ᬒ‫؀‬, ౉ᬒ༟,ࢁాҰ੒, ࢁᖒलߦ (ϙελʔൃද), ʮཧ‫ ݚ‬RIBF ʹ͓͚ΔϦϯάαΠΫϩτϩϯͷӡసใࠂʯ, ୈ 16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫ژ‬౎େֶ٢ాΩϟϯύε, ‫౎ژ‬, 2019 ೥ 7 ݄ 31 ೔–8 ݄ 3 ೔.
ᖛ஥੣, ෱ᖒ੟ࣇ, ੴ઒੝, খྛਗ਼ࢤ, খࢁ྄, ஥ଜ෢ࢤ, ੢ాູ, ੢ଜ੣, ࣲాॱᠳ, ݄‫ݑډ‬ढ़, ໼෌Ұ৻, ۚࢠ݈ଠ, খࢁా࿨޾, ాଜ‫࢙ڡ‬, ༡ࠤཅ, ਢా݈࢚, ౻‫ר‬ਖ਼थ, ෱੢ெঘ, ‫ޙ‬౻জ, ௕୩෦༟༤, ೔฻঵ӳ, ࠓඌߒ࢜, Ճ੉ণ೭, ্֞֎मҰ, ໦ࣉਖ਼‫ݑ‬, ࠐࢁඒ࡙,‫۽‬୩‫ࢠܡ‬, ਅՈ෢࢜, ௕੉੣, ௕༑ܼ, த઒޹ल, େ੢७Ұ, Ԟ໺޿थ, େؔ࿨‫و‬, ࡔຊ੒඙, ಺ࢁ‫ڿ‬ਔ, ౉෦ल, ౉ᬒ‫؀‬, ౉ᬒ༟, ࢁాҰ੒, খߴ߁র, େ৓޾ޫ (ϙελʔൃද), ʮཧ‫ ݚ‬AVF αΠΫϩτϩϯӡసͷ‫ݱ‬ঢ়ใࠂʯ, ୈ 16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫౎ژ‬େֶ٢ాΩϟϯύε, ‫౎ژ‬, 2019 ೥ 7 ݄ 31 ೔–8 ݄ 3 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Accelerator GroupBeam Dynamics & Diagnostics Team
1. Abstract

Aiming at stable and eﬃcient operation of the RIBF cascaded cyclotron system, Beam Dynamics and Diagnostics Team developes
power supplies, beam instrumentation, computer control and beam dynamic studies. We have successfully increased the beam availability for user experiments to more than 90%. We have also established small-beam-loss operations. The latter strongly contributes
to recent high-power operations at RIBF.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

More eﬃcient and stable operations of the RIBF cascaded cyclotron system
Maintenance and developments of the beam instrumentation
Developments of computer control system for more intelligent and eﬃcient operations
Maintenance and improvements of the magnet power supplies for more stable operations
Upgrade of the existing beam interlock system for high-power beams with few tens of kW

3. Summary of Research Activity(1) High-intensity heavy-ion beams such as 94-pnA uranium, 173-pnA xenon, 486-pnA krypton, and 740-pnA calcium beams
have been obtained.
(2) The world-first high-Tc SQUID beam current monitor has been developed.
(3) The bending power of the fixed-frequency Ring Cyclotron has been upgraded to 700 MeV.
(4) The world-most-intense V beams are stably supplied to super-heavy-element search experiments.
(5) The RIBF control system has been operated stably by replacing legacy hardware controllers carried over from our old facility
with new ones. Several useful operation tools are also developed.
(6) The dated power supplies exciting the main coils of RIKEN Ring Cyclotron has been upgrade to a new one having a betterlong-term stability than the old ones.

Members
Team Leader
Nobuhisa FUKUNISHI
Research/Technical Scientists
Masaki FUJIMAKI (Senior Technical Scientist)
Keiko KUMAGAI (Senior Technical Scientist)
Tamaki WATANABE (Senior Technical Scientist)

Kazunari YAMADA (Senior Technical Scientist)
Akito UCHIYAMA (Technical Scientist)

Expert Technician
Misaki KOMIYAMA
Postdoctoral Researcher
Takahiro NISHI
Visiting Scientists
Shin-ichiro HAYASHI (Hiroshima Int’l Univ.)
Atsushi KAMOSHIDA (Nat’l Instruments Japan Corporation)

Takuya MAEYAMA (Kitasato Univ.)

Student Trainee
Anri MOCHIZUKI (Kitasato Univ.)
Part-time Worker
Makoto NAGASE (Research Part-time Worker I)

List of Publications & Presentations
Publications[Original papers]
A. Uchiyama, T. Nagatomo, Y. Higurashi, J. Ohnishi, M. Komiyama, K. Kumagai, M. Fujimaki, H. Yamauchi, M. Tamura, K. Kaneko,
N. Fukunishi, and T. Nakagawa, “Control system for the new RIKEN 28-GHz superconducting electron cyclotron resonance ion source
for SRILAC,” Rev. Sci. Instrum. 91, 025101 (2020).
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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53[Proceedings]
T. Watanabe, H. Imao, O. Kamigaito, N. Sakamoto, N. Fukunishi, M. Fujimaki, K. Yamada, Y. Watanabe, T. Toyama, T. Miyao, A. Miura,
K. Hanamura, T. Kawachi, R. Koyama, and A. Kamoshida, “Calibration of the beam energy and position monitor system for the
RIKEN superconducting acceleration cavity,” Proceedings of the 2019 International Beam Instrumentation Conference (IBIC2019),
Pre-Release 1–3, Malmö, Sweden, September 8–12, 2019.
K. Yamada et al., “Construction of superconducting linac booster for heavy-ion linac at RIKEN Nishina Center,” Proc. SRF2019, TUP037,
Dresden, Germany, 2019-July, p. 504.
R. Koyama, A. Uchiyama, H. Imao, and T. Watanabe, “Upgrade of gas stripper control system for system integration at RIBF,” Proceedingsof the 16th Annual Meeting of Particle Accelerator Society of Japan, 865–868, Kyoto, Japan, July 31–August 3, 2019.
A. Uchiyama, M. Komiyama, K. Kumagai, E. Ikezawa, J. Ohnishi, H. Yamauchi, and M. Tamura, “Upgrade of electromagnet power
supply control at RILAC,” Proceedings of the 16th Annual Meeting of Particle Accelerator Society of Japan, 869–872, Kyoto, Japan,
July 31–August 3, 2019.
T. Watanabe, T. Toyama, K. Hanamura, H. ImaoA, O. Kamigaito, A. Kamoshida, T. Kawachi, R. Koyama, N. Sakamoto, N. Fukunishi,
M. Fujimaki, A. Miura, T. Miyao, K. Yamada, and Y. Watanabe, “Mapping measurement for beam energy position monitor system
for RIKEN superconducting acceleration cavity,” Proceedings of the 16th Annual Meeting of Particle Accelerator Society of Japan,
1105–1108, Kyoto, Japan, July 31–August 3, 2009.

Presentations[International conferences/workshops]
K. Yamada et al. (poster), “Construction of superconducting linac booster for heavy-ion linac at RIKEN Nishina Center,” 19th International Conference on RF Superconductivity (SRF2019), Dresden, Germany, June 30–July 5, 2019.
A. Uchiyama, T. Nagatomo, Y. Higurashi, J. Ohnishi, M. Komiyama, K. Kumagai, M. Fujimaki, H. Yamauchi, M. Tamura, K. Kaneko,
N. Fukunishi, and T. Nakagawa (poster), “Control system for the new RIKEN 28-GHz superconducting electron cyclotron resonanceion source for SRILAC,” The 18th International Conference on Ion Sources (ICIS2019), Lanzhou, China, September 1–6, 2019.
T. Watanabe, H. Imao, O. Kamigaito, N. Sakamoto, N. Fukunishi, M. Fujimaki, K. Yamada, Y. Watanabe, T. Toyama, T. Miyao, A. Miura,
K. Hanamura, T. Kawachi, R. Koyama, and A. Kamoshida, “Calibration of the beam energy and position monitor system for the
RIKEN superconducting acceleration cavity,” The 2019 International Beam Instrumentation Conference (IBIC2019), Malmö, Sweden,
September 8–12.
M. Komiyama et al. (poster), “Recent updates of the RIKEN RI Beam Factory control system,” The17th Biennial International Conferenceon Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2019), New York, USA, October 5–11, 2019.
K. Yamada (oral), “Cryomodule design, assembly and installation utilizing KOACH system,” TESLA Technology Collaboration (TTC)
Meeting 2020 at CERN, Geneva, Switzerland, February 4–7, 2020.

[Domestic symposium]
M. Komiyama, A. Uchiyama, and K. Kumagai (poster), “Beam Interlock System of RIKEN RI Beam Factory,” 7th Accelerator Facility
Safety Symposium, Tokai, Ibaragi, Japan, January 23–24, 2020.

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Research Facility Development Division
Accelerator Group
Cryogenic Technology Team
1. Abstract
We are operating the cryogenic system for the superconducting ring cyclotron in RIBF. We are operating the helium cryogenic
system in the south area of RIKEN Wako campus and delivering the liquid helium to users in RIKEN. We are trying to collecteﬃciently gas helium after usage of liquid helium.

2. Major Research Subjects(1) Operation of the cryogenic system for the superconducting ring cyclotron in RIBF.
(2) Operation of the helium cryogenic plant in the south area of Wako campus and delivering the liquid helium to users in Wako
campus.

3. Summary of Research Activity(1) Operation of the cryogenic system for the superconducting ring cyclotron in RIBF
(H. Okuno, T. Dantsuka, M. Nakamura, T. Maie).
(2) Operation of the helium cryogenic plant in the south area of Wako campus and delivering the liquid helium to users in Wako
campus.
(T. Dantsuka, S. Tsuruma, M. Kuroiwa, M. Takahashi, H. Okuno).

Members
Team Leader
Hiroki OKUNO
Research/Technical Scientists
Masato NAKAMURA (Senior Technical Scientist)
Expert Technicians
Tomoyuki DANTSUKA

Takeshi MAIE

Part-time Workers
Mamoru TAKAHASHI (Research Part-time Worker I)
Shizuho TSURUMA (Administrative Part-time Worker I)

Mayumi KUROIWA (Administrative Part-time Worker II)- 305 -

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Research Facility Development Division
Accelerator Group
Infrastructure Management Team
1. Abstract
Our team is in charge of operation, maintenance, and monitoring of research infrastructure of the whole RIBF, such as coolingwater system, air conditioner system, building equipment, and so on. It is very important to keep these infrastructures working properly
for the eﬀective and eﬃcient operation of RIBF.
We are also involved in the planning of the RIBF beam time, which is conducted by the RIBF User Liaison Team, through theestimation of the utility costs such as the electricity and the gas used for the power generator. Another important mission of our teamis to coordinate large-scale repair works carried out by the RIKEN Facility Section so that the beam time can proceed smoothly.
In the last three years, there were big construction works related to the upgrade project of the RILAC facility. We carried out thedesign of the SRF test facility, took part in the design work of the new building for radioisotope purification, jointly designed the ion
source room, and so on. The transfer work of GARIS II and the room-temperature cavities of the RILAC booster was conducted byour team.

2. Major Research Subjects(1) Operation, maintenance and monitoring of infrastructure of RI Beam Factory.
(2) Participation in the beam time planning through utility cost estimation.
(3) Coordination of large construction work and modification related to RI Beam Factory.

Members
Team Leader
Osamu KAMIGAITO (concurrent: Group Director, Accelerator Group)
Deputy Team Leader
Yutaka WATANABE (concurrent: Senior Technical Scientist,
RILAC Team.)Special Temporary Technical Scientist
Shu WATANABE
Special Temporary Employee
Hideyuki YAMASAWA

List of Publications & Presentations
Publications[Proceedings]
K. Suda, O. Kamigaito, K. Ozeki, N. Sakamoto, Y. Watanabe, K. Yamada, E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara,
A. Miyamoto, K. Sennyu, and T. Yanagisawa, “Fabrication and performance of superconducting quarter-wavelength resonators for
SRILAC,” Proceedings of the 19th International Conference on RF Superconductivity (SRF2019), Dresden, Germany, MOP055, 182(2019).
H. Imao, K. Yamada, N. Sakamoto, T. Watanabe, Y. Watanabe, O. Kamigaito, and K. Oyamada, “Non-evaporable getter-based diﬀerential pumping system for SRILAC at RIBF,” Proceedings of the 19th International Conference on RF Superconductivity (SRF2019),
Dresden, Germany, TUP013, 419 (2019).
K. Yamada, T. Dantsuka, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, T. Watanabe, Y. Watanabe,
E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara, A. Miyamoto, K. Sennyu, and T. Yanagisawa, “Construction of superconducting
linac booster for heavy-ion linac at RIKEN Nishina Center,” Proceedings of the 19th International Conference on RF Superconductivity(SRF2019), Dresden, Germany, TUP037, 504 (2019).
N. Sakamoto, T. Dantsuka, M. Fujimaki, H. Imao, O. Kamigaito, K. Kusaka, H. Okuno, K. Ozeki, K. Suda, A. Uchiyama, T. Watanabe,
Y. Watanabe, K. Yamada, E. Kako, H. Nakai, H. Sakai, K. Umemori, H. Hara, A. Miyamoto, K. Sennyu, and T. Yanagisawa, “Development of superconducting quarter-wave resonator and cryomodule for low-beta ion accelerators at RIKEN Radioactive Isotope Beam
Factory,” Proceedings of the 19th International Conference on RF Superconductivity (SRF2019), Dresden, Germany, WETEB1, 752(2019).
O. Kamigaito, T. Dantsuka, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, M. Kidera, M. Komiyama,
K. Kumagai, T. Maie, Y. Miyake, T. Nagatomo, T. Nakagawa, M. Nakamura, T. Nishi, J. Ohnishi, H. Okuno, K. Ozeki, N. Sakamoto,
K. Suda, A. Uchiyama, T. Watanabe, Y. Watanabe, and K. Yamada, “Recent progress in RIKEN RI Beam Factory,” Proceedings of
22nd International Conference on Cyclotrons and their Applications (CYC2019), Cape Town, South Africa, MOB01, (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

N. Tsukiori, K. Ozeki, S. Fukuzawa, M. Hamanaka, S. Ishikawa, K. Kobayashi, R. Koyama, T. Nakamura, M. Nishida, M. Nishimura,
J. Shibata, K. Yadomi, T. Dantsuka, M. Fujimaki, T. Fujinawa, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, O. Kamigaito, Y. Kanai, M. Kase, M. Kidera, M. Komiyama, K. Kumagai, T. Maie, M. Nagase, T. Nagatomo, T. Nakagawa, M. Nakamura,
J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, A. Uchiyama, S. Watanabe, T. Watanabe, Y. Watanabe, K. Yamada, and H. Yamasawa,“Status Report on the Operation of RIBF Ring Cyclotron,” Proceedings of the 16th Annual Meeting of Particle Accelerator Society ofJapan (PASJ2019), July 31–August 3, 2019, Kyoto, Japan, FSPH002, 1193 (2019).
M. Hamanaka, K. Suda , A. Goto, J. Ohnishi, Y. Oshiro, S. Fukuzawa, S. Ishikawa, R. Koyama, T. Nakamura, M. Nishida, M. Nishimura,
J. Shibata, N. Tsukiori, K. Yadomi, K. Kaneko, K. Oyamada, M. Tamura, Akira Yusa, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, H. Imao, M. Kase, O. Kamigaito, M. Kidera, M. Komiyama, K. Kumagai, T. Maie, M. Nagase, T. Nagatomo, T. Nakagawa,
H. Okuno, K. Ozeki, N. Sakamoto, A. Uchiyama, S. Watanabe, T. Watanabe, Y. Watanabe, K. Yamada, and Y. Kotaka, “Status report on the operation of RIKEN AVF Cyclotron,” Proceedings of the 16th Annual Meeting of Particle Accelerator Society of Japan(PASJ2019), July 31–August 3, 2019, Kyoto, Japan, FSPH010, 1224 (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Instrumentation Development Group
1. Abstract
This group develops core experimental installations at the RI Beam factory. Three projects are currently going on. SLOWRI is anexperimental installations under testing and a common element enabling multiple-use. This will stop high-energy RI beams in a gascatcher system and re-accelerates up to several-tenth keV, and the high-quality cold RI beam will be delivered to the users. SCRIT is
the world first facility for an electron scattering oﬀ unstable nuclei, and has been constructed independently of the RIBF main facility.
The first physic result was demonstrated in 2017, and the facility is now under upgrading of the electron beam power driving the RI
beam production. Rare-RI Ring is an event-by-event operated heavy-ion storage ring aiming at the precision mass measurement for
extremely rare exotic nuclei. This is now open for an experimental proposal application, and has already performed PAC-approved
experiments, and an improvement for higher precise mass measurement is now going on. All instrumentations were designed tomaximize the research potential of the world’s most intense RI beams, and the exclusive equipment available at the RI Beam Factorymakes experimental challenges possible. Technologies and experiences accumulated in this group will be able to provide opportunitiesof new experimental challenges and the foundation for future developments of RIBF.

2. Major Research Subjects
(1)
(2)
(3)
(4)

SCRIT Project
SLOWRI Project
Rear RI Ring Project
RUNBA project (Beam recycling development)

3. Summary of Research Activity
We are developing beam manipulation technology in carrying out above listed project. They are the high-quality slow RI beam
production (SCRIT and SLOWRI), the beam cooling and stopping (SCRIT and SLOWRI), and the beam accumulation technology(Rare RI Ring) in a storage ring. The technological knowhow accumulated in our projects will play a significant role in the next
generation RIBF. Status and future plan for each project is described in subsections. The electron scattering from 132 Xe isotopes has
been successfully measured and the nuclear charge density distribution has been obtained in SCRIT. We are ready for the electrons
scattering experiments for unstable nuclei. Rare RI Ring has been commissioned and the performances has been evaluated. We
have demonstrated a mass-measurement capability of R3 and successfully started mass-measurements for unknown-mass nuclei inthe experiments approved by PAC. Recently, we succeeded in measurement of masses of 74, 76 Ni, 122 Rh, and 124 Pd for the first time.
SLOWRI is now under test experiments to establish a slow RI beam production using two types of gas cells. PALIS has beencommissioned from 2015, and basic functions such as, for instance, the RI-beam stopping in Ar gas cell and the extraction from thegas cell have beam evaluated. RF ion-guide gas cell is now under testing and it will be online-commissioned in this year. Future plans
for these projects are described in subsections.
We have started a new project from last year. According to the future plan of Nishina center, we are going to develop a beam
re-cycling technique. A circulation of an RI beam in a storage ring equipped by a thin internal target is maintained until that somenuclear reaction happen at the target. The circulating beam losses the energy and the emittance grows up turn by turn because ofexisting internal target. In order to establish a beam re-cycling technique, the energy loss and growth of the energy-spread and theemittance have to be compensated by using a re-acceleration system and a beam-cooling or a fast feedback system. A beam re-cycling
technique is supposed to greatly enhance an RI use eﬃciency in a nuclear physics study. As a first step for the development of thesenovel technique, we will construct a testbench consisting of a relatively small size of heavy-ion storage ring that will be connect
to our ISOL (ERIS) in SCRIT facility. This ring named RUNBA (Recycled-Unstable-Nuclear Beam Accumulator) is equipped byacceleration devices and beam-cooling devices necessary in our R&D study. It was originally constructed as a beam cooler ring (sLSR) at the Institute for Chemical Research (ICR), Kyoto University more than ten years ago. This has been already moved to RIBF
in last year, and will be re-constructed by the SCRIT system in following year. Technical development for key devices required in
RUNBA such as a charge breeder, an energy-spread compensator, and an internal target system have been already started under the
research cooperation agreement with ICR Kyoto University.

Members
Director
Masanori WAKASUGIContract Researcher
Ryo OGAWARA- 308 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Visiting Scientists
Yasushi ABE (Nat’l Inst. of Radiological Sci.)
Akira OZAWA (Tsukuba Univ.)

Fumi SUZAKI (JAEA)

Student Trainees
So Sato (Rikkyo Univ.)

Shu TAKAGI (Kyoto Univ.)

Part-time Worker
Midori TAKEMON (Administrative Part-time Worker I)

List of Publications & Presentations
Publications and presentations are listed in subsections.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Instrumentation Development GroupSLOWRI Team
1. Abstract

SLOWRI is a universal low-energy RI-beam facility at RIBF that provides a wide variety of short-lived nuclei as high-purity andlow-emittance ion beams or stored ions in a trap, including a parasitic operation mode. The SLOWRI team develops and manages
the facility and performs high-precision spectroscopy experiments. The construction of the SLOWRI facility began in FY2013 andcommissioning work is ongoing. From April 1st in FY2019, SLOWRI has been started to be co-operated under RNC and WNSC/KEK
collaboration.
High-energy radioactive ion beams from the projectile fragment separator BigRIPS are thermalized in a large He gas catcher cell
(RFC cell) or in a small Ar gas catcher cell (PALIS cell). From these gas cells, the low-energy ion beams will be delivered via mass
separators and switchyards to various devices: such as an ion trap, a collinear fast beam apparatus, and a multi-reflection time of flightmass spectrograph. A multi-reflection time-of-flight mass spectrograph (MRTOF) has been also developed.
Two mass measurement projects using MRTOF mass spectrographs have been started: one is for trans uranium elements at the
GARIS facility and the other is for r-process nuclides at SLOWRI facility. At GARIS-II, we installed second prototype SLOWRI
combined with MRTOF, which is a medium-sized cryogenic RF-carpet He gas cell. Using second prototype SLOWRI, more than 80
nuclear masses have been measured including first mass measurements of Md and Es isotopes. In FY2019, the mass measurement for257
Db has been successfully performed at GARIS-II, and the mass has been directly determined for the first time. At SLOWRI facility,
third prototype SLOWRI is under construction, which is a 50-cm-long RF-carpet-type He gas cell combined with MRTOF. The third
prototype will be installed at F11 of BigRIPS, downstream of ZeroDegree spectrometer, which can provide symbiotic measurementswith other BigRIPS experiments.
Parallelly, the on-line commissioning for PALIS has been continuously performed at F2 of BigRIPS. For the optimization of
optical components on SLOWRI beam line, which connects between these gas cells installed at BigRIPS and an experimental room,
a compact cesium ion source was installed at the upstream of the beam line in FY2019.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Construction of the stopped and low-energy RI-beam facility, SLOWRI.
Development of a multi-reflection time-of-flight mass spectrograph for precision mass measurements of short-lived nuclei.
Development of collinear laser spectroscopy apparatus.
Development of a parasitic slow RI-beam production method using resonance laser ionization.
Commissioning for SLOWRI beam line.

3. Summary of Research Activity(1) Construction of stopped and low-energy RI-beam facility (SLOWRI)SLOWRI consists of two gas catchers (RF carpet gas cell and PALIS gas cell), mass separators a 50-m-long beam transport line,
a beam cooler-buncher, an isobar separator, and a laser system. The RF carpet gas cell will be installed at the exit of the D5 dipole
magnet of BigRIPS. The gas catcher contains a large cryogenic He gas cell with a large traveling wave rf-carpet. The PALIS gas cellis installed in the vicinity of the second focal plane slit of BigRIPS. It will provide parasitic RI-beams from those ions lost in the slits
during other experiments. In this gas catcher, thermalized RI ions quickly become neutral and will be re-ionized by resonant laser
radiations. Oﬀ- and on-line commissioning is underway.
Based on test experiments with the prototype setups, the RF-carpet gas cell contains a three stage rf-carpet structure: a gutter rf
carpet (1st carpet) for the collection thermal ions in the cell into a small slit, a narrow (about 10 mm) traveling-wave rf-carpet (2ndcarpet) for collection of ions from the gutter carpet and for transporting the ions towards the exit, and a small rf carpet for extraction
from the gas cell. In FY2019, we modified the 1st carpet to have a finer pitch which was reduced by 20% compared with the previous
version, in order to improve the transport eﬃciency. We tested the transport performance of the new 1st carpet using Cs+ ions provided
with a surface ionization ion source installed inside the gas cell. As the result, we have successfully achieved 80% transport eﬃciency
in a He gas of 133 mbar. As combined with a transport eﬃciency on the 2nd carpet, we confirmed more than 70% extraction eﬃciency
from the gas cell for the Cs+ ions which were collected onto the RF carpets.
We will install the RF-carpet gas cell combined with MRTOF at F11 of BigRIPS at first, where the on-line commissioning andsystematic mass measurements will be started from FY2020. At F11, symbiotic measurements with other BigRIPS experiments such
as HiCARI projects can be performed.
(2) Development of a multi-reflection TOF mass spectrograph for short-lived nuclei
The atomic mass is one of the most important quantities of a nucleus and has been studied in various methods since the earlydays of modern physics. From among many methods we have chosen a multi-reflection time-of-flight (MRTOF) mass spectrometer.
Slow RI beams extracted from the RF ion-guide are bunched and injected into the spectrometer with a repetition rate of ∼100 Hz. A
mass-resolving power of 170,000 has been obtained with a 2 ms flight time for 40 K and 40 Ca isobaric doublet. This mass-resolving
power should allow us to determine ion masses with an accuracy of ≤10−7 .
The MR-TOF mass spectrograph has been placed under the GARIS-II separator aiming at direct mass measurements of trans-- 310 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

uranium elements. A medium-sized cryogenic He gas cell was placed at the focal plane of GARIS-II and a bunched low-energy heavy
ion beam was transported to the trap of MRTOF. Mass measurements of more than 80 nuclides, including short-lived (T 1/2 = 10 ms)
isotopes of Ra and several isotopes of the trans-uranium elements Fm, Es, No and Md were performed in collaboration with Wako
Nuclear Science Center (WNSC) of KEK and Super Heavy Element Synthesis team of RIKEN. In FY2019, the mass measurement of
a super heavt element of 257 Db has been successfully performed, and the mass has been dilectly measured for the first time.
A new MRTOF has been assembled in FY2019 to be coupled with the third SLOWRI protype gass cell, which will be installed at
F11 of BigRIPS. Using an ion source of K+ , the oﬄine commissioning has been sucessflully performed. As the result, an impressive
mass- resolving power of 570,000 has been achived.
(3) Development of collinear fast beam apparatus for nuclear charge radii measurements
The root-mean-square charge radii of unstable nuclei have been determined exclusively by isotope shift measurements of the
optical transitions of singly charged ions or neutral atoms by laser spectroscopy. Many isotopes of alkali, alkali-earth, and noble-gas
elements in addition to several other elements have been measured by collinear laser spectroscopy since these ions all have good
optical transitions and are available at conventional ISOL facilities. However, isotopes of other elements, especially refractory andshort-lived ones, have not been investigated so far.
In SLOWRI, isotopes of all atomic elements will be provided as well collimated, mono-energetic ion beams. This should expand
the range of nuclides available for laser spectroscopy. In the first years of the RIBF project, elements in the vicinity of Ni, suchas Ni, Co, Fe, Cr, Cu, Ga, and Ge are planned to be investigated. They all have possible optical transitions in the ground states ofneutral atoms with presently available laser systems. Some of them have so called recycling transitions, which enhance the detection
probabilities noticeably. Furthermore, the multistep resonance ionization (RIS) method can be applied to the isotopes of Ni as well as
those of some other elements. The required minimum intensity for this method can be as low as 10 atoms per second.
An oﬀ-line mass separator and a collinear fast beam apparatus with a large solid-angle fluorescence detector was built previously.
A 617-nm transition of the metastable Ar+ ion at 20 keV was measured with both collinear and anti-collinear geometry, which allowed
determination of the absolute resonant frequency of the transition at rest with a relative accuracy better than 10−8 . A new setup isunder preparation at the SLOWRI experiment area in collaboration with the Ueno nuclear spectroscopy laboratory.
(4) Development of parasitic slow RI-beam production scheme using resonance laser ionization
More than 99.9% of RI ions produced in projectile fission or fragmentation are simply dumped in the first dipole magnet and theslits. A new scheme, named PALIS, meant to rescue such precious RI using a compact gas catcher cell and resonance laser ionization,
was proposed as a part of SLOWRI. The thermalized RI ions in a cell filled with Ar gas can be quickly neutralized and transported
to the exit of the cell by gas flow. Irradiation of resonance lasers at the exit ionizes neutral RI atoms eﬃciently and selectively. The
resonance ionization scheme itself can also be a useful method to perform hyperfine structure spectroscopy of RI of many elements.
In FY2019, we had two on-line experiments and a part of the experimental result was published in Prog. Theor. Exp. Phys. (Seeour publication list) Technical developments are under progress in on- and oﬀ-line commissioning.
(5) Commissioning for SLOWRI beam line
SLOWRI beam line composes of four dipole magnets, two focal plane chambers, 62 electrostatic quadrupole singlets, 11 electrostatic quadrupole quartets and 7 beam profile monitors. The hardware construction has been almost finished. In order to tune theoptical components, a compact ion source, which can be used as a side-inserted type device, has been installed at the upstream of thebeam line. We will start the tuning for the beam line using Cs+ ions provided from the ion source in FY2020.

Members
Team Leader
Hironobu ISHIYAMA
Research/Technical Scientists
Takao KOJIMA (Senior Research Scientist)
Aiko TAKAMINE (Research Scientist)

Tetsu SONODA (Technical Scientist)

Expert Technician
Takeshi MAIE
Junior Research Associate
Shun IIMURA
Visiting Scientists
Hideki IIMURA (JAEA)
Kunihiro OKADA (Sophia Univ.)
Mikael REPONEN (Univ. of Jyvaskyla)
Hans SCHUESSLER (Texas A&M Univ.)

Volker SONNENSCHEIN (Nagoya Univ.)
Minoru TANIGAKI (Kyoto Univ.)
Hideki TOMITA (Nagoya Univ.)
Hermann WOLLNIK (Univ. of Giessen)Student Trainees- 311 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Ryunosuke KODAMA (Univ. of Electro-Commun.)

Kento SUZUKI (Univ. of Electro-Commun.)Part-time Workers
Ichirou KATAYAMA (Research Part-time Worker I)

Marco ROSENBUSCH (Research Part-time Worker I)

List of Publications & Presentations
Publications[Original papers]
T. Sonoda, I. Katayama, M. Wada, H. Iimura, V. Sonnenschein, S. Iimura, A. Takamine, M. Rosenbusch, T. M. Kojima, D. S. Ahn,
N. Fukuca, T. Kubo, S. Nishimura, Y. Shimizu, H. Suzuki, H. Takaeda, M. Tanigaki, H. Tomita, K. Yoshida, and H. Ishiyama, “Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beam in the parasitic gas cell,” Progress of Theoretical and Experimental Physics, 2019-11, 113D02, (2019).
M. Rosenbusch, M. Wada, P. Schury, Y. Ito, H. Ishiyama, S. Ishizawa, Y. Hirayama, S. Kimura, T. M. Kojima, H. Miyatake, J. Y. Moon,
T. Niwase, T. Sonoda, A. Takamine, Y. X. Watanabe, and H. Wollnik, “A new multi-reflection time-of-flight mass spectrograph for the
SLOWRI facility,” Nucl. Instrum. Methods Phys. Res. B 463, 184–188 (2020).
P. Aschere, N. Althubiti, D. Atanasov, K. Blaum, R. B. Cakirli, S. Grevy, F. Herfurth, S. Kreim, D. Lunney, V. Manea, D. Neidherr,
M. Rosenbusch, L. Schweikhard, A. Welker, F. Wienholtz, R. N. Wolf, and K. Zuber, “Mass measurements of neutron-rich isotopes
near N = 20 by in trap decay with the ISOLTRAP spectrometer,” Phys. Rev. C 100, 014304 (2019).
H. Wollnik, M. Wada, P. Schury, M. Rosenbusch, Y. Ito, and H. Miyatake, “Time-of-flight mass spectrographs of high mass resolving
power,” International Journal of Modern Physics A, doi:10.1142/S0217751X19420016, (2019).
T. Niwase, M. Wada, P. Schury, H. Haba, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, K. Moromoto, K. Morita, M. Rosenbusch,
H. Wollnik, T. Shanley, and Y. Benari, “Development of an alpha-TOF detector for correlated measurement of atomic masses and decay
properties,” Nucl. Instrum. Methods Phys. Res. A 953, 163198 (2020).
P. Schury, M. Wada, H. Wollnik, J. -Y. Moon, T. Hashimoto, and M. Rosenbusch, “High-stability, high-voltage power supplies for use
with multi-reflection time-of-flight mass spectrographs,” Rev. Sci. Instrum. 91, 014702 (2020)
S. Sels, P. Fischer, H. Heylem, V. Lagaki, S. Lechner, F. M. Maier, P. Plattner, M. Rosenbusch, F. Wienholts, R. N. Wolf, W. Nortershauser,
L. Schweikhard, and S. Malbrunot-Ettenauer, “First steps in the development of the multi ion reflection apparatus for collinear laser
spectroscopy,” Nucl. Instrum. Methods Phys. Res. B 463, 310–314 (2020).
S. Lechner, P. Fischer, H. Heylen, V. Lagaki, F. Maier, P. Plattner, M. Rosenbush, S. Sels, F. Wienholtz, R. N. Wolf, W. Nortershauser,
L. Schweikhard, and S. Malbrunot-Ettenauer, “Fluorescence detection as a new diagnostics tool for electrostatic ion beam traps,”
Hyperfine Interactions 240, 95 (2019).
Y. Hirayama, Y. X. Watanabe, M. Mukai, P. Schury, M. Ahmed, H. Ishiyama, S. C. Jeong Y. Kakiguchi, S. Kimura, J. Y. Moon, M. Oyaizu,
J. H. Park, M. Wada, and H. Miyatake, “Nuclear spectroscopy of r-process nuclei using KEK Isotope Separation System,” Nucl. Instrum.
Methods Phys. Res. A 463, 425–430 (2020).
M. Mukai, Y. Hirayama, P. Schury, Y. X. Watanabe, M. Ahmed, H. Haba, H. Ishiyama, S. C. Jeong, Y. Kakiguchi, S. Kimura, J. Y. Moon,
M. Oyaizu, A. Ozawa, J. H. Park, H. Ueno, M. Wada, and H. Miyatake, “Development of a multi-segmented proportional gas counterfor beta-decay spectroscopy at KISS,” Nucl. Instrum. Methods Phys. Res. B 463, 421–424 (2020).
N. Kimura, R. Kodama, K. Suzuki, S. Oishi, M. Wada, K. Okada, N. Ohmae, H. Katori, and N. Nakamura, “Direct determination of theenergy of the first excited fine structure level in Ba6+ ,” Phys. Rev. A 100, 052508, (2019)[Proceedings]
Y. X. Watanabe, Y. Hirayama, P. Schury, Y. Kakiguchi, M. Oyaizu, M. Wada,M. Miyatake, M. Mukai, S. Kimura, H. Ishiyama, S. C. Jeong,
J. Y. Moon, and J. H. Park, “Production of neutron-rich nuclei by multinucleon transfer reactions at KISS project” Exotic Nuclei, 486–
491 (2019).
Y. X. Watanabe, Y. Hirayama, M. Mukai, M. Ahmed, Y. Kakiguchi, H. Miyatake, M. Oyaizu, P. Schury, M. Wada, S. Kimura, H. Ishiyama,
S. C. Jeong, J. Y. Moon, and J. H. Park, “Experimental studies of neutron-rich nuclei around N = 126 at KEK isotope separation system,”
EPJ Web Conf. 223, 01069 (2019).

Presentations[International conferences/workshops]
H. Tomita, V. Sonnenschein, R. Terabayashi, M. Ohashi, S. Kato, S. Suzuki, K. Saito, Y. Matsui, T. Sakazaki, T. Iguchi, N. Nishizawa,T. Sonoda, H. Ishiyama, and K. Yoshida (poster), “Development of frequency comb based laser absorption/ionization spectroscopy ofradioactive isotopes”, International Conference on Laser Probing (PLATAN 2019), Helmholz Institute, Mainz, May 19–24, 2019.
A. Takamine (invited), “Recent progress in the development of gas cells, and SHE results combining GARIS with GASCELL + MRTOF”,
Expert Meeting on Next-Generation in-Flight Separators, GSI FAIR, Darmstadt, Germany, October 1, 2019.
H. Ishiyama (invited), “Present status of SLOWRI”, RIBF Users Meeting 2019, RIKEN, Japan, September 4, 2019.
H. Ishiyama (invited), “Present status of SLOWRI”, SSRI-PNS collaboration meeting 2019, RIKEN, Japan, September 4, 2019.
S. Iimura, A. Takamine, J. Liu, S. Chen, M. Rosenbusch, M. Wada, and H. Ishiyama (poster), “Development of gas cell to stop and collecthigh energy RI beam, and extract radioactive ions with a high eﬃciency”, The ALL RIKEN Workshop 2019, RIKEN, Japan, December
5–6, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53[Domestic conferences/workshops]෋ాӳੜ, V. Sonnenschein, Ճ౻߂ଠ࿠, ࣉྛྏฏ, ੢ᖒయ඙, Ҫ‫ޱ‬఩෉, M. Reponen, Ԃా఩, ੴࢁത߃, ࿨ాಓ࣏, ยࢁҰ࿠, ஛ాߒ೭, ླ໦ߒ, ਗ਼ਫཅฏ, ٢ాޫҰ, ൧ଜल‫ل‬, ߴๆѪࢠ, M. Rosenbuch, খౡོ෉, ‫ٱ‬อහ޾, K. Wendt (‫ޱ‬಄ൃද), ʮཧԽֶ‫ڀݚ‬
ॴ RI ϏʔϜϑΝΫτϦʔ௿଎ RI ϏʔϜੜ੒૷ஔʹ͓͚Δ‫ڞ‬໐ΠΦϯԽϨʔβʔΠΦϯ‫ݯ‬ͷ։ൃʯ, ࣍ੈ୅์ࣹઢγϯϙδ΢Ϝ
2019, ट౎େֶ౦‫ژ‬, ౦‫ژ‬, 2019 ೥ 8 ݄ 8–9 ೔.
൧ଜढ़ (‫ޱ‬಄ൃද), ʮཧ‫ ݚ‬BigRIPS SLOWRI ʹ͓͚Δ RF ΧʔϖοτΨεηϧͷ։ൃʯ, ‫ژ‬େෳ߹‫ݚ‬ઐ໳‫ڀݚ‬ձʮ୹ण໋֩ RI Λ༻͍ͨ֩෼ޫͱ֩෺ੑ‫ ڀݚ‬VIʯ݉ʮୈ 11 ճఀࢭɾ௿଎ RI ϏʔϜΛ༻͍ͨ֩෼ޫ‫ڀݚ‬ձʯ, ‫ژ‬େෳ߹‫ݚ‬, ‫౎ژ‬, 2020 ೥ 1 ݄ 16–17 ೔.
ߴๆѪࢠ (‫ޱ‬಄ൃද), ʮ֩ɾ෺࣭Պֶ‫΁ڀݚ‬ͷԠ༻Λ໨ࢦͨ͠ߴภ‫ ۃ‬RI ϏʔϜੜ੒ʯ, ‫ژ‬େෳ߹‫ݚ‬ઐ໳‫ڀݚ‬ձʮ୹ण໋֩ RI Λ༻͍ͨ֩෼ޫͱ֩෺ੑ‫ ڀݚ‬VIʯ݉ʮୈ 11 ճఀࢭɾ௿଎ RI ϏʔϜΛ༻͍ͨ֩෼ޫ‫ڀݚ‬ձʯ, ‫ژ‬େෳ߹‫ݚ‬, ‫౎ژ‬, 2020 ೥ 1 ݄ 16–17 ೔.
ੴࢁത߃ (‫ޱ‬಄ൃද), ʮ์ࣹੑτϨʔαʔ 8 Li ๏Ͱ‫ݻ‬ମి஑ք໘ͷϦν΢Ϝ֦ࢄ͸௥੻Մೳ͔ʁʯ, ‫ژ‬େෳ߹‫ݚ‬ઐ໳‫ڀݚ‬ձʮ୹ण໋
֩ RI Λ༻͍ͨ֩෼ޫͱ֩෺ੑ‫ ڀݚ‬VIʯ݉ʮୈ 11 ճఀࢭɾ௿଎ RI ϏʔϜΛ༻͍ͨ֩෼ޫ‫ڀݚ‬ձʯ, ‫ژ‬େෳ߹‫ݚ‬, ‫౎ژ‬, 2020 ೥ 1
݄ 16–17 ೔.

Outreach activities
H. Ishiyama (school master), S. Iimura (school staﬀ), and T. Kojima (school staﬀ), Nishina School 2019, Riken, Wako, Japan, July
30–August 1, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Instrumentation Development Group
Rare RI-ring Team
1. Abstract

The aim of Rare-RI Ring (R3) is to measure the masses of short-lived unstable nuclei far from the beta-stability line. In particular,a high-precision mass measurement for nuclei located around the r-process pass (rare-RI) is required in nucleosynthesis point of view.
The R3 completed the construction at the end of 2014, and has been performed commissioning experiments several times by 2017.
Through the commissioning experiments, we confirmed the high ability of R3 as a storage ring capable of handling one event, anddemonstrated that it is possible to perform the time-of-flight Isochronous Mass Spectrometry (IMS) in shorter than 1 ms. We haveacquired an adequate eﬃciency to conduct the mass measurement experiments in the end of 2017. In 2018, we have successfully
conducted the first mass measurement experiment for 74, 76 Ni, 122 Rh, 123, 124 Pd, and 125 Ag. The analysis is in progress for giving
the new experimental mass values of 74, 76 Ni, 122 Rh, 124 Pd, and for improving the experimental mass values of 123 Pd, 125 Ag. The
remaining issues as the R3 facility are further improvement of experimental eﬃciency and that of mass measurement precision. In
2019, we started eﬀorts to resolve those issues.

2. Major Research Subjects(1) Further improvement of experimental eﬃciency and mass measurement precision(2) Precision mass measurement for rarely produced isotopes related to r-process

3. Summary of Research Activity

In the commissioning experiments up to 2017, we confirmed the unique performances of R3 and demonstrated the time-of-flightisochronous mass measurement method. The ring structure of R3 was designed with a similar concept of a separate-sector ring
cyclotron. It consists of six sectors and straight sections, and each sector consists of four rectangular bending magnets. Two magnets
at both ends of each sector are additionally equipped with ten trim coils to form a precise isochronous field. We have realized informing the precise isochronous field of 5 ppm with wide momentum range of ∆p/p = ±0.5%. Another performance required forR3 is to eﬃciently seize hold of an opportunity of the mass measurement for rare-RIs produced unpredictably. It was realized byconstructing the Isotope-Selectable Self-trigger Injection (ISSI) scheme which pre-identified rare-RI itself triggers the injection kicker
magnets. Key device was an ultra-fast response kicker system that has been successfully developed. Full activation of the kicker
magnetic field can be completed within the flight time of the rare-RI from an originating point (F3 focal point in BigRIPS) of thetrigger signal to the kicker position in R3.
Since R3 accumulates, in principle, only one event, we fabricated high-sensitive beam diagnostic devices in the ring. They should
be applicable even for one event circulation. One of them is a cavity type of Schottky pick-up installed in a straight section of R3.
The Schottky pick-up successfully monitored a single 78 Kr36+ ion circulation with the measurement time of less than 10 ms in the firstcommissioning experiment. We also confirmed that it is useful for fine tuning of the isochronous field. Another is a timing monitor,
which detects secondary electrons emitted from thin carbon foil placed on the circulation orbit. The thickness of the foil is 50 µg/cm2 .
This timing monitor is working well to observe first several tens turns for injected event.
We performed mass measurement in the third commissioning experiment by using unstable nuclei which masses are well-known.
The masses of 79 As, 77 Ga, 76 Zn, and 75 Cu relative to 78 Ge were derived with the accuracy of less than 10 ppm. In addition, we have
improved the extraction eﬃciency to 2% by considering the matching condition between the emittance of injection events and theacceptance of R3. This extraction eﬃciency was suﬃcient to conduct the accepted two proposals: mass measurements of Ni isotopes
and mass measurements of Sn region.
In the beginning of 2018, we examined the feasibility of these two proposals in detail. Consequently, we decided to proceedwith two proposals at the same period. In the beginning of November 2018, we have conducted the first experiment using the R3 to
measure the masses for 74, 76 Ni in 4 days. After that, we also measured the masses for 122 Rh, 123, 124 Pd, and 125 Ag in 4.5 days at theend of November 2018. These nuclei were successfully extracted from R3 with the eﬃciency of 1–2%. The masses of 74, 76 Ni, 122 Rh,
and 124 Pd can be determined experimentally for the first time. On the other hand, the masses of 123 Pd and 125 Ag will be improved theprecision compared with previous experimental values. These analyses are still in progress. Since each proposal has a machine timeof several days to measure the masses of exotic nuclei, we will plan to conduct the mass measurements of the other Ni isotopes andnuclei of Sn region in 2020 or later.
With further improvements in experimental eﬃciency and mass measurement precision, the R3 enables mass measurement of
extremely rare-RIs that are inaccessible for other techniques. In 2019, we started to add one more kicker magnet. More accurate
injection and reliable extraction will be possible, the experimental eﬃciency will be improved about 10 times from the previous
experiment. We plan to conduct a beam test in 2020.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Members
Team Leader
Masanori WAKASUGI
Research/Technical Scientist
Yoshitaka YAMAGUCHI (Technical Scientist)
Expert Technician
Takeshi MAIE
Visiting Scientists
Yasushi ABE (Nat’l Inst. of Radiological Sci.)

Fumi SUZAKI (JAEA)

List of Publications & Presentations
Publications[Original papers]
X. Xu, M. Wang, K. Blaum, J. D. Holt, Yu. A. Litvinov, A. Schwenk, J. Simonis, S. R. Stroberg, Y. H. Zhang, H. S. Xu, P. Shuai, X. L. Tu,
X. H. Zhou, F. R. Xu, G. Audi, R. J. Chen, X. C. Chen, C. Y. Fu, Z. Ge, W. J. Huang, S. Litvinov, D. W. Liu, Y. H. Lam, X. W. Ma,
R. S. Mao, A. Ozawa, B. H. Sun, Y. Sun, T. Uesaka, G. Q. Xiao, Y. M. Xing, T. Yamaguchi, Y. Yamaguchi, X. L. Yan, Q. Zeng,
H. W. Zhao, T. C. Zhao, W. Zhang, and W. L. Zhan, “Masses of neutron-rich 52–54 Sc and 54, 56 Ti nuclides: The N = 32 subshell closurein scandium,” Phys. Rev. C 99, 064303 (2019).
X. Xu, J. H. Liu, C. X. Yuan, Y. M. Xing, M. Wang, Y. H. Zhang, X. H. Zhou, Yu. A. Litvinov, K. Blaum, R. J. Chen, X. C. Chen,
C. Y. Fu, B. S. Gao, J. J. He, S. Kubono, Y. H. Lam, H. F. Li, M. L. Liu, X. W. Ma, P. Shuai, M. Si, M. Z. Sun, X. L. Tu, Q. Wang,
H. S. Xu, X. L. Yan, J. C. Yang, Y. J. Yuan, Q. Zeng, P. Zhang, X. Zhou, W. L. Zhan, S. Litvinov, G. Audi, S. Naimi, T. Uesaka,
Y. Yamaguchi, T. Yamaguchi, A. Ozawa, B. H. Sun, K. Kaneko, Y. Sun, and F. R. Xu, “Masses of ground and isomeric states of 101 In
and configuration-dependent shell evolution in odd-A indium isotopes,” Phys. Rev. C 100, 051303(R) (2019).
F. C. Ozturk, B. Akkus, D. Atanasov, H. Beyer, F. Bosch, D. Boutin, C. Brandau, P. Buehler, R. B. Cakirli, R. J. Chen, W. D. Chen,
X. C. Chen, I. Dillmann, C. Dimopoulou, W. Enders, H. G. Essel, T. Faestermann, O. Forstner, B. S. Gao, H. Geissel, R. Gernhaeuser,
R. E. Grisenti, A. Gumberidze, S. Hagmann, T. Heftrich, M. Heil, M. O. Herdrich, P. -M. Hillenbrand, T. Izumikawa, P. Kienle,
C. Klaushofer, C. Kleﬀner, C. Kozhuharov, R. K. Knoebel, O. Kovalenko, S. Kreim, T. Kuehl, C. Lederer-Woods, M. Lestinsky,
S. A. Litvinov, Yu. A. Litvinov, Z. Liu, X. W. Ma, L. Maier, B. Mei, H. Miura, I. Mukha, A. Najafi, D. Nagae, T. Nishimura,
C. Nociforo, F. Nolden, T. Ohtsubo, Y. Oktem, S. Omika, A. Ozawa, N. Petridis, J. Piotrowski, R. Reifarth, J. Rossbach, R. Sanchez,
M. S. Sanjari, C. Scheidenberger, R. S. Sidhu, H. Simon, U. Spillmann, M. Steck, Th. Stoehlker, B. H. Sun, L. A. Susam, F. Suzaki,
T. Suzuki, S. Yu. Torilov, C. Trageser, M. Trassinelli, S. Trotsenko, X. L. Tu, P. M. Walker, M. Wang, G. Weber, H. Weick, N. Winckler,
D. F. A. Winters, P. J. Woods, T. Yamaguchi, X. D. Xu, X. L. Yan, J. C. Yang, Y. J. Yuan, Y. H. Zhang, X. H. Zhou, and the FRS-ESR,
ILIMA, SPARC, and TBWD Collaborations, “New test of modulated electron capture decay of hydrogen-like 142 Pm ions: Precision
measurement of purely exponential decay,” Phys. Lett. B 797, 134800 (2019).
J. T. Zhang, K. Yue, H. X. Li, X. L. Tu, C. J. Shao, P. Ma, B. Mei, X. C. Chen, Y. Y. Yang, X. Q. Liu, Y. M. Xing, K. H. Fang, Z. Y. Sun,
M. Wang Yu. A. Litvinov, T. Yamaguchi, P. Egelhof, Y. H. Zhang, and X. H. Zhou, “The development of in-ring reaction measurements
at the HIRFL-CSR,” Nucl. Instrum. Methods Phys. Res. A 948, 162848-1–5 (2019)[Proceedings]
Z. Ge, T. Uesaka, S. Naimi, D. Nagae, Y. Abe, S. Omika, F. Suzaki, T. Yamaguchi, Y. Yamaguchi, M. Wakusugi, H. Li, K. Wakayama,
H. Arakawa, K. Inomata, K. Nishimuro, T. Kobayashi, A. Ozawa, S. Hosoi, Y. Inada, S. Suzuki, T. Moriguchi, M. Mukai, M. Amano,
D. Kamioka, and Y. Yano, “Scheme of high-resolution identification and selection of secondary Ions for mass measurements with theRare-RI Ring,” Hyper. Int. 240 92/1–11 (2019).

Presentations[International conferences/workshops]
A. Ozawa (invited), “Mass measurements for Ni-isotopes in Rare-RI Ring, RIBF,” China-Japan Collaboration Workshop on Nuclear Massand Life for Unraveling Mysteries of R-process, Beijing, China, October 10–12, 2019.
T. Yamaguchi (invited), “New experimental plan and detector R&D at the Rare-RI Ring facility,” China-Japan Collaboration Workshop
on Nuclear Mass and Life for Unraveling Mysteries of R-process, Beijing, China, October 10–12, 2019.

[Seminars]
T. Yamaguchi, “Charge changing cross section measurement—A possible method to extract point-proton radii of radioactive isotopes,”
Beihang Univ., Beijing, China, October 14, 2019.

[Domestic conferences/workshops]޲Ҫ΋΋ʢ‫ޱ‬಄ൃදʣ, ʮബບΛར༻ͨ͠ඈߦ࣌ؒ‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄
17–20 ೔.
Ҵా߁ਓʢ‫ޱ‬಄ൃදʣ, ʮ‫ك‬গ RI ϦϯάͷͨΊͷϑΝΠόʔγϯνϨʔγϣϯ‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

ࡉҪॣʢ‫ޱ‬಄ൃදʣ, ʮ‫ك‬গ RI ϦϯάͷͨΊബບΛར༻ͨ͠Ґஔ‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬,2019 ೥ 9 ݄ 17–20 ೔.
ࢁ‫ޱ‬༝ߴʢট଴ߨԋʣ, ʮRIBF ʹ͓͚ΔॏΠΦϯ஝ੵϦϯάʯ, Ӊ஦࢙‫ڀݚ‬ηϯλʔߏ੒һձٞ, ஜ೾େֶ, ͭ͘͹, 2019 ೥ 11 ݄
21 ೔.
௕ߐେีʢ‫ޱ‬಄ൃදʣ, ʮ‫ك‬গ RI ϦϯάͰͷཻࢠ஝ੵ֬ೝͷҝͷඈߦ࣌ؒ‫ݕ‬ग़‫ث‬ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ‫ݱ‬஍։࠵தࢭ,2020 ೥ 3 ݄ 16–19 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Instrumentation Development GroupSCRIT Team
1. Abstract

The SCRIT Electron Scattering Facility has been constructed at RIKEN RIBF. This aims at investigation of internal nuclear
structure for short-lived unstable nuclei by means of electron scattering. SCRIT (Self-Confining RI Ion Target) is a novel method
to form internal targets in an electron storage ring. This is a unique method for making electron scattering experiments for unstable
nuclei possible. Construction of the facility has been started in 2009. This facility consists of an electron accelerator (RTM), a SCRITequipped electron storage ring (SR2), an electron-beam-driven RI separator (ERIS), and a window-frame spectrometer for electron
scattering (WiSES) which consists of a large window-frame dipole magnet, drift chambers and trigger scintillators. Installationof all components in the facility was completed in 2015. After the comprehensive test and tuning, the luminosity was reached to
3 × 1027 /(cm2 s) with the number of injected ions of 3 × 108 . In 2016, we successfully completed a measurement of diﬀraction of
scattered electrons from 132 Xe nuclei and determined the charge density distribution for the first time. The facility is now under setting
up to move the first experiment for unstable nuclei.

2. Major Research Subjects

Development of SCRIT electron scattering technique and measurement of the nuclear charge density distributions of unstable
nuclei.

3. Summary of Research Activity

SCRIT is a novel technique to form internal target in an electron storage ring. Positive ions are three dimensionally confined in theelectron beam axis by transverse focusing force given by the circulating electron beam and applied electrostatic longitudinal mirror
potential. The created ion cloud composed of RI ions injected from outside works as a target for electron scattering. Constructionof the SCRIT electron scattering facility has been started in 2009. The electron accelerators RTM and the storage ring SR2 weresuccessfully commissioned in 2010. Typical accumulation current in SR2 is 250–300 mA at the energy range of 100–300 MeV that isrequired energy range in electron scattering experiment. The SCRIT device was inserted in the straight section of SR2 and connected
to an ISOL named ERIS (Electron-beam-driven RI separator for SCRIT) by 20-m long low energy ion transport line. A buncher
system based on RFQ linear trap named FRAC (Fringing-RF-field-Activated dc-to-pulse converter) was inserted in the transport line
to convert the continuous beam from ERIS to pulsed beam, which is acceptable for SCRIT. The detector system WiSES consisting ofa high-resolution magnetic spectrometer, drift chambers and trigger scintillators, was constructed, and it has a solid angle of 100 msr,
energy resolution of 10−3 , and the scattering angle coverage of 25–55 degrees. A wide range of momentum transfer, 80–300 MeV/c,
is covered by changing the electron beam energy from 150 to 300 MeV.
We successfully measured a diﬀraction pattern in the angular distribution of scattered electron from 132 Xe isotope at the electron
beam energy of 150 MeV, 200 MeV, and 300 MeV, and derived the nuclear charge distribution by assuming two-parameters Fermi
model for the first time. At this time, luminosity was reached to 3 × 1027 /(cm2 s) at maximum and the averaged value was 1.2 ×1027 /(cm2 s) with the number of injected target ions of 3 × 108 .
We are now under preparation for going to the experiments for unstable nuclei. There are some key issues for that. They are
increasing the intensity of the RI beams from ERIS, eﬃcient DC-to-pulse conversion at FRAC, improving the transmission eﬃciency
from FRAC to SCRIT, and eﬀective suppression of the background in measurement of scattered electrons. RI beam intensity will be
improved by upgrading the electron beam power from 10 W to 60 W, increasing the contained amount of U in the target ion source,and some modifications in mechanical structure in the ion source. For upgrading the electron beam power, the RF system of RTM
has been maintained intensively, and we will continue the development of RTM. For eﬃcient DC-to-pulse conversion, we establishedthe two-step bunching method, which is time compression at FRAC in combination with pre-bunching at the ion source using gridaction. Furthermore, we will improve the conversion eﬃciency and the transmission eﬃciency from FRAC to the SCRIT device bycooling the trapped ions using minuscule amounts of a buﬀer gas. These improvements on FRAC were already confirmed in oﬀ-line
test. Since one of significant contribution to the background for scattered electron is scattering from massive structural objects aroundthe trapping region originated from halo components of the electron beam, we remodeled the SCRIT electrodes. The vacuum pumpsystem at the SCRIT device has been upgraded to reduce the contribution of residual gases. Luminosity for radioactive Xe isotopes is
expected to be more than 1026 /(cm2 s) after these improvements. Then, we will be able to start experiments for unstable nuclei. Whenfurther upgrading in the RTM power planed to be 3 kW will be achieved, we can extend the measurements to more exotic nuclei.
In 2018, we developed several instruments. One is the introduction of the surface-ionization type ion source at ERIS in order
to increase kinds of radioactive beam and to produce high intensity beam. Another development is the upgrading of the drift chamber located in front of the magnetic spectrometer of WiSES to improve the momentum resolution and angular acceptance. Thesedevelopments help us to realize experiments for unstable nuclei.
In 2019, we installed a newly designed SCRIT electrodes. The main purpose of the replacement was to lower the background
during the measurement due to the electron scattering from the SCRIT electrodes itself but not from the ion targets for the experiment.
For that purpose, we employed thin metal wires to construct the electrodes rather than metal plates nor blocks. In addition, we
modified the inside structure of the SCRIT chamber to symmetrize the electric ground potential aﬀecting the potential curve inside theelectrodes. Currently, we are adjusting the SR2 accelerator and ion source ERIS to be ready for the measurement by means of the new- 317 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

SCRIT electrodes.

Members
Team Leader
Masanori WAKASUGI
Research/Technical Scientists
Masamitsu WATANABE (Senior Research Scientist)

Tetsuya OHNISHI (Senior Technical Scientist)

Expert Technician
Takeshi MAIE
Contract Researcher
Akitomo ENOKIZONO
Research Consultants
Takashi EMOTO
Masahiro HARA

Shinichi ICHIKAWA

Senior Visiting Scientist
Toshitada HORI (Hiroshima Univ.)
Visiting Scientists
Toshimi SUDA (Tohoku Univ.)
Tadaaki TAMAE (Tohoku Univ.)
Kyo TSUKADA (Tohoku Univ.)

Yuki HONDA (Tohoku Univ.)
Kazuyoshi KURITA (Rikkyo Univ.)
Shuo WANG (Shandong Univ.)

Student Trainees
Taihei AOYAGI (Tohoku Univ.)
Syota TAKAYAMA (Tohoku Univ.)

Daisuke TAKI (Tohoku Univ.)
Hikari WAUKE (Tohoku Univ.)

List of Publications & Presentations
Publications[Proceedings]
K. Tsukada, K. Adachi, A. Enokizono, T. Fujita, M. Hara, T. Hori, M. Hori, S. Ichikawa, K. Kasama, K. Kurita, K. Namba, T. Ohnishi,
T. Suda, T. Tamae, M. Togasaki, M. Wakasugi, M. Watanabe, and K. Yamada, “Electron scattering from 208 Pb and 132 Xe ions at the
SCRIT facility,” Hyperfine interact 240, 1–120 (2019).

Presentations[International conferences/workshops]
T. Suda (invited), “Proton charge radius by low-energy electron scattering,” International Workshop on the Structure of the Proton,
Yamagata, February 10–11, 2019.
T. Suda (oral), “Nuclear physics with low-energy and high-intensity electron beam,” Neutrino Nuclear Response 2019 (NNR19), RCNP,
Osaka, Japan, May 8–9, 2019.
T. Suda (invited), “Electron scattering for short-live nuclei,” Gordon Conference on “Exploring simple structural patterns and dynamics
of nuclei,” New London US, June 16–21, 2019.
T. Suda (invited), “Nuclear physics with electron beam,” Connecting Fundamental Physics, Chemistry and the Origins of Biomolecular
Homochirality, National Observatory of Japan, June 26–27, 2019.
S. Sato (oral), M. Wakasugi, T. Ohnishi, M. Watanabe, A. Enokizono, and K. Kurita, “Improvement of a dc-to-pulse conversion eﬃciency
of FRAC,” The 13th International Conference on Stopping and Manipulation of Ions and related topics (SMI2019), Montreal, Canada,
July 16–19, 2019.
T. Suda (plenary/invited), “Electron scattering for short-lived nuclei,” International Nuclear Physics Conference (INPC2019), Glasgow
UK, July 29–August 2, 2019.
M. Watanabe (poster), A. Enokizono, M. Hara, Y. Honda, T. Hori, S. Ichikawa, K. Kasama, K. Kurita, M. Nakano, K. Namba, T. Oonishi,
S. Sato, T. Suda, S. Takayama, T. Tamae, K. Tsukada, M. Wakasugi, and H. Wauke, “Fine optimization of SCRIT facility for short-lived
nuclei experiment,” International Nuclear Physics Conference (INPC2019), Glasgow, UK, July 29–August 2, 2019.
T. Suda (invited), “Proton radius,” The 11th Circum-Pan-Pacific Symposium on High Energy Spin Physics, Miyazaki Japan, August
27–30, 2019.
H. Wauke (poster), T. Aoyagi, A. Enokizono, Y. Honda, T. Suda, S. Takayama, T. Tamae, K. Tsukada, T. Ohnishi, M. Wakasugi, andM. Watanabe, “Precise magnetic field measurement of electron spectrometer for the electron scattering oﬀ unstable nuclei experiment,”
International school for Strangeness Nuclear Physics 2019, Tohoku Univ., Sendai, Japan, September 5–8, 2019.

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K. Tsukada (oral), T. Aoyagi, A. Enokizono, M. Hara, Y. Honda, T. Hori, S. Ichikawa, K. Kurita, T Ohnishi, S. Sato, T. Suda, S. Takayama,
T. Tamae, M. Wakasugi, and M. Watanabe, “Present status and future prospects of the SCRIT electron scattering facility,” 9th International Symposium on Nuclea1r Symmetry Energy (NuSYM2019), Danang City, Vietnam, September 30–October 4, 2019.
T. Suda (invited), “Proton radius,” 14th Asia-Pacific Physics Conference (APPC2019), Kuching Malaysia, November 17–22, 2019.
K. Tsukada (oral), T. Aoyagi, A. Enokizono, M. Hara, Y. Honda, T. Hori, S. Ichikawa, K. Kurita, T Ohnishi, S. Sato, T. Suda,
T. Tamae, M. Wakasugi, and M. Watanabe, “Present status of SCRIT electron scattering facility,” 14th Asia-Pacific Physics Conference(APPC2019), Sarawak, Malaysia, November 17–22, 2019.
T. Suda (invited), “Electron-scattering activities in Japan for nucleon and nuclei,” KVI Seminar, KVI Groningen, Netherlands, January 8,
2019.
T. Suda (invited), “ULQ2 project,” Collaborative Seminar by REIMEI, RCNP and Clusters, February 2020.
T. Ohnishi (oral), A. Enokizono, M. Hara, T. Hori, S. Ichikawa, K. Kurita, R. Ogawara, S. Sato, T. Suda, S. Takayama, D. Taki, S. Takagi,
T. Tamae, K. Tsukada, M. Wakasugi, M. Watanabe, and H. Wauke, “Electron scattering with unstable nuclei at the SCRIT electron
scattering facility,” Vth Topical Workshop on Modern Aspects in Nuclear Structure—The Many Facets of Nuclear Structure, Bormio,
Italy, February 4–9, (2020).

[Domestic conferences/workshops]ਢాརඒʢট଴ߨԋʣ, ʮΨϯϚઢϏʔϜΛ༻͍ͨ‫֩ࢠݪ‬ɾϋυϩϯ෺ཧͷ৽‫ہ‬໘ͱࠓ‫ޙ‬ͷల๬ʯ, ௿ΤωϧΪʔɾେిྲྀిࢠϏʔϜͱ‫֩ࢠݪ‬෺ཧ, RCNP ‫ڀݚ‬ձ, େࡕ, 2019 ೥ 3 ݄ 4–5 ೔.
ਢాརඒʢট଴ߨԋʣ, ʮཅࢠͷαΠζ͕͓͔͍͠ʁʯ, ౦‫ژ‬େֶ෺ཧֶ‫ࣨڭ‬ίϩΩ΢Ϝ, ౦‫ژ‬, 2019 ೥ 11 ݄ 8 ೔.
࿨Ӊ‫͔ͻܚ‬Γʢ‫ޱ‬಄ൃදʣ, ʮSCRIT ిࢠεϖΫτϩϝʔλʔͷ 3 ࣍‫࣓ݩ‬৔ଌఆʯ, ౦๺େֶཧֶ‫ڀݚ‬Պ 6 ઐ߈+ੜ໋Պֶ‫ڀݚ‬Պ߹ಉγϯϙδ΢Ϝ 2020, ౦๺େֶ, 2020 ೥ 2 ݄ 14 ೔.
࿨Ӊ‫͔ͻܚ‬Γʢϙελʔൃදʣ, ௩ా‫ڿ‬, ੨༄ହฏ, ਢాརඒ, ∁ࢁ঵ଠ, ୍େ༞, ‫ߐۄ‬஧໌, ຊଟ༎‫ه‬, ʮSCRIT ిࢠεϖΫτϩϝʔλʔͷ 3 ࣍‫࣓ݩ‬৔ଌఆʯ, ELPH γϯϙδ΢Ϝ, ౦๺େֶ ELPH, ઋ୆, 2019 ೥ 3 ݄ 6 ೔.
ࠤ౻૵ʢ‫ޱ‬಄ൃදʣ, ӿԂতஐ, େ੢఩໵, ‫ా܀‬࿨޷, ਢాརඒ, ௩ా‫ڿ‬, ࿨Ӊ‫͔ͻܚ‬Γ, एਿণಙ, ౉ᬑਖ਼ຬ, ʮSCRIT ࣮‫ݧ‬ͷͨΊͷߴޮ཰ RFQ Ϋʔϥʔόϯνϟʔͷ։ൃʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
࿨Ӊ‫͔ͻܚ‬Γʢ‫ޱ‬಄ൃදʣ, ੨༄ହฏ, ӿԂতஐ, େ੢఩࠸, ‫ా܀‬࿨޷, ࠤ౻૵, ਢాརඒ, ߴ໦प, ∁ࢁ঵ଡ, ୍େ༞, ‫ߐۄ‬஧໌, ௩ా‫ڿ‬, ຊଟ༎‫ه‬, एਿণಙ, ౉ᬑਖ਼ຬ, ʮSCRIT ిࢠεϖΫτϩϝʔλʔͷ 3 ࣍‫࣓ݩ‬৔ଌఆʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
௩ా‫ڿ‬ʢ‫ޱ‬಄ൃදʣ, ੨༄ଠฏ, ࢢ઒ਐҰ, ӿԂতஐ, େ੢఩࠸, ‫ా܀‬࿨޷, ࠤ౻૵, ਢాརඒ, ߴࢁ঵ଡ, ୍େ༞, ‫ߐۄ‬஧໌, ‫ݪ‬խ߂, ງར‫ڡ‬, ຊଟ༎‫ه‬, ࿨Ӊ‫͔ͻܚ‬Γ, एਿণಙ, ౉ᬑਖ਼ຬ, ʮ୸ૉඪతΛ༻͍ͨ SCRIT ࣮‫ࢠి༻ݧ‬εϖΫτϩϝʔλͷੑೳධՁʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.

[International seminars/lectures]
T. Suda, Lectures: “Electron scattering for nucleon and nuclei,” Johannesburg, South Africa, October 19–November 3, 2019.
T. Suda, Public lecture: “Nihonium: 113th element,” Johannesburg, South Africa, October 19–November 3, 2019.

[Domestic seminars/lectures]ਢాརඒ, ʮిࢠઢ֩෺ཧಛ࿦ʯ, େֶӃߨٛ, 2019 ೥ 10 ݄–2020 ೥ 3 ݄.
ਢాརඒ, ʮӉ஦૑ੜ෺ཧֶ֓࿦ʯ, GPPU ߨٛ, 2019 ೥ 6 ݄.
ਢాརඒ, ʮ‫ݩ‬ૉʹ͍ͭͯʯ, ‫۽‬୩ߴߍ๚໰ੜ΁ͷಛผߨٛ, 2019 ೥ 8 ݄ 26 ೔.
ਢాརඒ, “Physics Today,” ৽ׁେֶूதߨٛ, 2019 ೥ 12 ݄ 3–5 ೔.
ਢాརඒ, ʮ‫ݩ‬ૉͱ‫֩ࢠݪ‬ʯ, ‫۽‬୩ߴߍಛผत‫ۀ‬, 2019 ೥ 12 ݄ 6 ೔.
ਢాརඒ, ʮ೔ຊͰൃ‫͞ݟ‬Εͨ 113 ൪৽‫ݩ‬ૉχϗχ΢Ϝʯ, ઋ୆੨ྕத౳ֶߍग़લत‫ۀ‬, 2019 ೥ 12 ݄ 10 ೔.

AwardsH. Wauke, SNP School Incentive Prize, “Precise magnetic field measurement of electron spectrometer for the electron scattering oﬀ
unstable nuclei experiment,” International school for Strangeness Nuclear Physics 2019, Tohoku Univ., Sendai, Japan, September 5–8,
2019.

Others
T. Ohnishi, A. Enokizono, M. Hara, T. Hori, S. Ichikawa, K. Kurita, R. Ogawara, S. Sato, T. Suda, S. Takayama, D. Taki, S. Takagi,
T. Tamae, K. Tsukada, M. Wakasugi, M. Watanabe, and H. Wauke, “The SCRIT project at RIKEN,” NUSTAR Annual Meeting 2020,
GSI, Darmstadt, Germany, March 2–6, (2020).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Research Instruments Group
1. Abstract
The Research Instruments Group is the driving force at RI Beam Factory (RIBF) for continuous enhancement of activities andcompetitiveness of experimental research. Consisting of four teams, we are in charge of the operation, maintenance, and improvementof the core research instruments at RIBF, such as the BigRIPS in-flight RI separator, ZeroDegree spectrometer and SAMURAI spectrometer, and the related infrastructure and equipment. We are also in charge of the production and delivery of RI beams using the
BigRIPS separator. The group also conducts related experimental research as well as R&D studies on the research instruments.

2. Major Research Subjects
Design, construction, operation, maintenance, and improvement of the core research instruments at RIBF and related R&D studies.
Experimental studies on exotic nuclei.

3. Summary of Research Activity
The current research subjects are summarized as follows:(1) Production and delivery of RI beams and related research(2) Design, construction, operation, maintenance, and improvement of the core research instruments at RIBF and their related
infrastructure and equipment(3) R&D studies on the core research instruments and their related equipment at RIBF
(4) Experimental research on exotic nuclei using the core research instruments at RIBF

Members
Director
Tomohiro UESAKA
Contract Researcher
Toshiyuki KUBO
Junior Research Associate
Rieko TSUNODA
Senior Visiting Scientist
Toshio KOBAYASHI (Tohoku Univ.)
Student Trainee
Fumitaka ENDO (Tohoku Univ.)- 320 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Research Instruments GroupBigRIPS Team
1. Abstract
This team is in charge of design, construction, development and operation of BigRIPS in-flight separator and its related research
instruments at RI beam factory (RIBF). They are employed not only for the production of RI beams but also the experimental studies
using RI beams.

2. Major Research Subjects
Design, construction, development and operation of BigRIPS in-flight separator, RI-beam transport lines, and their related research
instruments

3. Summary of Research Activity
This team is in charge of design, construction, development and operation of BigRIPS in-flight separator, RI-beam transport lines,
and their related research instruments such as ZeroDegree spectrometer at RI beam factory (RIBF). They are employed not only forthe production of RI beams but also various kinds of experimental studies using RI beams. The research subjects may be summarized
as follows:(1) General studies on RI-beam production using in-flight scheme.
(2) Studies on ion-optics of in-flight separators, including particle identification of RI beams.
(3) Simulation and optimization of RI-beam production.
(4) Development of beam-line detectors and their data acquisition system.
(5) Experimental studies on production reactions and unstable nuclei.
(6) Experimental studies of the limits of nuclear binding.
(7) Development of superconducting magnets and their helium cryogenic systems.
(8) Development of a high-power production target system.
(9) Development of a high-power beam dump system.
(10) Development of a remote maintenance and remote handling systems.
(11) Operation, maintenance and improvement of BigRIPS separator system, RI-beam transport lines, and their related research
instruments such as ZeroDegree spectrometer and so on.
(12) Experimental research using RI beams.

Members
Team Leader
Koichi YOSHIDA
Research/Technical Scientists
Yoshiyuki YANAGISAWA (Senior Research Scientist)
Naohito INABE (Senior Technical Scientist)
Kensuke KUSAKA (Senior Technical Scientist)

Masao OHTAKE (Senior Technical Scientist)
Naoki FUKUDA (Technical Scientist)
Hiroyuki TAKEDA (Technical Scientist)

Contract Researchers
Deuk Soon AHN
Yohei SHIMIZU

Hiroshi SUZUKI

Visiting Scientists
Alan Matthew AMTHOR (Bucknell Univ.)
Daniel P. BAZIN (Michigan State Univ.)
Alfredo ESTRADE VAZ (Central Michigan Univ.)
Michael FAMIANO (Western Michigan State Univ.)
Hans GEISSEL (GSI/Justus-Liebig Univ. Giessen)
Tuomas Arne Santeri GRAHN (Univ. of Jyvaskyla)
Kazuo IEKI (Rikkyo Univ.)

Naohito IWASA (Tohoku Univ.)
Yutaka MIZOI (Univ. of Electro-Commun.)David MORRISSEY (Michigan State Univ.)
Mauricio PORTILLO (Michigan State Univ.)
Bradley M. SHERRILL (Michigan State Univ.)
Oleg TARASOV (Michigan State Univ.)

Student Trainee
Shunki ISHIKAWA (Tohoku Univ.)- 321 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Part-time Worker
Tetsuro KOMATSUBARA (Research Part-time Worker I)

List of Publications & Presentations
Publications[Original papers]
Y. Ichikawa, H. Nishibata, Y. Tsunoda, A. Takamine, K. Imamura, T. Fujita, T. Sato, S. Momiyama, Y. Shimizu, D. S. Ahn, K. Asahi,
H. Baba, D. L. Balabanski, F. Boulay, J. M. Daugas, T. Egami, N. Fukuda, C. Funayama, T. Furukawa, G. Georgiev, A. Gladkov,
N. Inabe, Y. Ishibashi, T. Kawaguchi, T. Kawamura, Y. Kobayashi, S. Kojima, A. Kusoglu, I. Mukul, M. Niikura, T. Nishizaka,
A. Odahara, Y. Ohtomo, T. Otsuka, D. Ralet, G. S. Simpson, T. Sumikama, H. Suzuki, H. Takeda, L. C. Tao, Y. Togano, D. Tominaga,
H. Ueno, H. Yamazaki, and X. F. Yang, “Interplay between nuclear shell evolution and shape deformation revealed by the magnetic
moment of 75 Cu,” Nat. Phys. 15, 321 (2019).
Z. Q. Chen, Z. H. Li, H. Hua, H. Watanabe, C. X. Yuan, S. Q. Zhang, G. Lorusso, S. Nishimura, H. Baba, F. Browne, G. Benzoni,
K. Y. Chae, F. C. L. Crespi, P. Doornenbal, N. Fukuda, G. Gey, R. Gernhäuser, N. Inabe, T. Isobe, D. X. Jiang, A. Jungclaus, H. S. Jung,
Y. Jin, D. Kameda, G. D. Kim, Y. K. Kim, I. Kojouharov, F. G. Kondev, T. Kubo, N. Kurz, Y. K. Kwon, X. Q. Li, J. L. Lou, G. J. Lane,
C. G. Li, D. W. Luo, A. Montaner-Pizá, K. Moschner, C. Y. Niu, F. Naqvi, M. Niikura, H. Nishibata, A. Odahara, R. Orlandi, Z. Patel,
Zs. Podolyák, T. Sumikama, P. -A. Söderström, H. Sakurai, H. Schaﬀner, G. S. Simpson, K. Steiger, H. Suzuki, J. Taprogge, H. Takeda,
Zs. Vajta, H. K. Wang, J. Wu, A. Wendt, C. G. Wang, H. Y. Wu, X. Wang, C. G. Wu, C. Xu, Z. Y. Xu, A. Yagi, Y. L. Ye, andK. Yoshinaga, “Proton shell evolution below 132 Sn: first measurement of low-lying β-emitting isomers in 123, 125 Ag,” Phys. Rev. Lett.
122, 212502 (2019).
D. Lubos, J. Park, T. Faestermann, R. Gernhäuser, R. Krücken, M. Lewitowicz, S. Nishimura, H. Sakurai, D. S. Ahn, H. Baba, B. Blank,
A. Blazhev, P. Boutachkov, F. Browne, I. Čeliković, G. de France, P. Doornenbal, Y. Fang, N. Fukuda, J. Giovinazzo, N. Goel,
M. Górska, S. Ilieva, N. Inabe, T. Isobe, A. Jungclaus, D. Kameda, Y. K. Kim, I. Kojouharov, T. Kubo, N. Kurz, Y. K. Kwon, G. Lorusso,
K. Moschner, D. Murai, I. Nishizuka, Z. Patel, M. M. Rajabali, S. Rice, H. Schaﬀner, Y. Shimizu, L. Sinclair, P. -A. Söderström,
K. Steiger, T. Sumikama, H. Suzuki, H. Takeda, Z. Wang, N. Warr, H. Watanabe, J. Wu, and Z. Xu, “Improved value for the gamowteller strength of the 100 Sn beta decay,” Phys. Rev. Lett. 122, 222502 (2019).
D. S. Ahn, N. Fukuda, H. Geissel, N. Inabe, N. Iwasa, T. Kubo, K. Kusaka, D. J. Morrissey, D. Murai, T. Nakamura, M. Ohtake, H. Otsu,
H. Sato, B. M. Sherrill, Y. Shimizu, H. Suzuki, H. Takeda, O. B. Tarasov, H. Ueno, Y. Yanagisawa, and K. Yoshida, “Location of theneutron dripline at fluorine and neon,” Phys. Rev. Lett. 123, 212501 (2019).
H. Watanabe, H. K. Wang, G. Lorusso, S. Nishimura, Z. Y. Xu, T. Sumikama, P. -A. Söderström, P. Doornenbal, F. Browne, G. Gey,
H. S. Jung, J. Taprogge, Zs. Vajta, J. Wu, A. Yagi, H. Baba, G. Benzoni, K. Y. Chae, F. C. L. Crespi, N. Fukuda, R. Gernhäuser,
N. Inabe, T. Isobe, A. Jungclaus, D. Kameda, G. D. Kim, Y. K. Kim, I. Kojouharov, F. G. Kondev, T. Kubo, N. Kurz, Y. K. Kwon,
G. J. Lane, Z. Li, C. -B. Moon, A. Montaner-Pizá, K. Moschner, F. Naqvi, M. Niikura, H. Nishibata, D. Nishimura, A. Odahara,
R. Orlandi, Z. Patel, Zs. Podolyák, H. Sakurai, H. Schaﬀner, G. S. Simpson, K. Steiger, Y. Sun, H. Suzuki, H. Takeda, A. Wendt,
and K. Yoshinaga, “New isomers in 125 Pd79 and 127 Pd81 : Competing proton and neutron excitations in neutron-rich palladium nuclides
towards the N = 82 shell closure,” Phys. Lett. B 792, 263 (2019).
A. Corsi, Y. Kubota, J. Casal, M. Gómez-Ramos, A. M. Moro, G. Authelet, H. Baba, C. Caesar, D. Calvet, A. Delbart, M. Dozono,
J. Feng, F. Flavigny, J. -M. Gheller, J. Gibelin, A. Giganon, A. Gillibert, K. Hasegawa, T. Isobe, Y. Kanaya, S. Kawakami, D. Kim,
Y. Kiyokawa, M. Kobayashi, N. Kobayashi, T. Kobayashi, Y. Kondo, Z. Korkulu, S. Koyama, V. Lapoux, Y. Maeda, F. M. Marqués,
T. Motobayashi, T. Miyazaki, T. Nakamura, N. Nakatsuka, Y. Nishio, A. Obertelli, A. Ohkura, N. A. Orr, S. Ota, H. Otsu, T. Ozaki,
V. Panin, S. Paschalis, E. C. Pollacco, S. Reichert, J. -Y. Rousse, A. T. Saito, S. Sakaguchi, M. Sako, C. Santamaria, M. Sasano,
H. Sato, M. Shikata, Y. Shimizu, Y. Shindo, L. Stuhl, T. Sumikama, Y. L. Sun, M. Tabata, Y. Togano, J. Tsubota, T. Uesaka, Z. H. Yang,
J. Yasuda, K. Yoneda, and J. Zenihiro, “Structure of 13 Be probed via quasi-free scattering,” Phys. Lett. B 797, 134843 (2019).
G. X. Zhang, H. Watanabe, G. D. Dracoulis, F G. Kondev, G. J. Lane, P. H. Regan, P. -A. Söderström, P. M. Walker, K. Yoshida,
H. Kanaoka, Z. Korkulu, P. S. Lee, J. J. Liu, S. Nishimura, J. Wu, A. Yagi, D. S. Ahn, T. Alharbi, H. Baba, F. Browne, A. M. Bruce,
M. P. Carpenter, R. J. Carroll, K. Y. Chae, C. J. Chiara, Zs. Dombradi, P. Doornenbal, A. Estrade, N. Fukuda, C. Griﬃn, E. Ideguchi,
N. Inabe, T. Isobe, S. Kanaya, I. Kojouharov, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, T Lauritsen, C. S. Lee, E. J. Lee,
C. J. Lister, G. Lorusso, G. Lotay, E. A. McCutchan, C. -B. Moon, I. Nishizuka, C. R. Nita, A. Odahara, Z. Patel, V. H. Phong,Zs. Podolyák, O. J. Roberts, H. Sakurai, H. Schaﬀner, D. Seweryniak, C. M. Shand, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda,
S. Terashima, Zs. Vajta, J. J. Valiente-Dóbon, Z. Y. Xu, and S. Zhu, “Interplay of quasiparticle and vibrational excitations: First
observation of isomeric states in 168 Dy and 169 Dy,” Phys. Lett. B 799, 135036 (2019).
P. J. Davies, J. Park, H. Grawe, R. Wadsworth, R. Gernhäuser, R. Krücken, F. Nowacki, D. S. Ahn, F. Ameil, H. Baba, T. Bäck, B. Blank,
A. Blazhev, P. Boutachkov, F. Browne, I. Cěliković, M. Dewald, P. Doornenbal, T. Faestermann, Y. Fang, G. de France, N. Fukuda,
A. Gengelbach, J. Gerl, J. Giovinazzo, S. Go, N. Goel, M. Górska, E. Gregor, H. Hotaka, S. Ilieva, N. Inabe, T. Isobe, D. G. Jenkins,
J. Jolie, H. S. Jung, A. Jungclaus, D. Kameda, G. D. Kim, Y. -K. Kim, I. Kojouharov, T. Kubo, N. Kurz, M. Lewitowicz, G. Lorusso,
D. Lubos, L. Maier, E. Merchan, K. Moschner, D. Murai, F. Naqvi, H. Nishibata, D. Nishimura, S. Nishimura, I. Nishizuka, Z. Patel,
N. Pietralla, M. M. Rajabali, S. Rice, H. Sakurai, H. Schaﬀner, Y. Shimizu, L. F. Sinclair, P. -A. Söderström, K. Steiger, T. Sumikama,
H. Suzuki, H. Takeda, J. Taprogge, P. Thöle, S. Valder, Z. Wang, N. Warr, H. Watanabe, V. Werner, J. Wu, Z. Y. Xu, A. Yagi,
K. Yoshinaga, and Y. Zhu, “Toward the limit of nuclear binding on the N = Z line: Spectroscopy of 96 Cd,” Phys. Rev. C 99, 021302(R)(2019).
J. Park, R. Krücken, D. Lubos, R. Gernhäuser, M. Lewitowicz, S. Nishimura, D. S. Ahn, H. Baba, B. Blank, A. Blazhev, P. Boutachkov,
F. Browne, I. Čeliković, G. de France, P. Doornenbal, T. Faestermann, Y. Fang, N. Fukuda, J. Giovinazzo, N. Goel, M. Górska,- 322 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

H. Grawe, S. Ilieva, N. Inabe, T. Isobe, A. Jungclaus, D. Kameda, G. D. Kim, Y. -K. Kim, I. Kojouharov, T. Kubo, N. Kurz, Y. K. Kwon,
G. Lorusso, K. Moschner, D. Murai, I. Nishizuka, Z. Pate, M. M. Rajabali, S. Rice, H. Sakurai, H. Schaﬀner, Y. Shimizu, L. Sinclair,
P. -A. Söderström, K. Steiger, T. Sumikama, H. Suzuki, H. Takeda, Z. Wang, H. Watanabe, and J. Wu, “New and comprehensive β- andβp-decay spectroscopy results in the vicinity of 100 Sn,” Phys. Rev. C 99, 034313 (2019).
V. H. Phong, G Lorusso, T. Davinson, A. Estrade, O. Hall, J. Liu, K. Matsui, F. Montes, S. Nishimura, A. Boso, P. H. Regan, R. Shearman,
Z. Y. Xu, J. Agramunt, J. M. Allmond, D. S. Ahn, A. Algora, H. Baba, N. T. Brewer, C. G. Bruno, R. Caballero-Folch, F. Calvino,
M. Wolińska-Cichocka, G. Cortes, I. Dillmann, C. Domingo-Pardo, A. Gargano, S. Go, C. J. Griﬃn, R. K. Grzywacz, L. HarknessBrennan, T. Isobe, A. Jungclaus, D. Kahl, L. H. Khiem, G. Kiss, A. Korgul, S. Kubono, K. Miernik, A. I. Morales, N. Nepal, M. Piersa,
Zs. Podolyák, B. C. Rasco, K. P. Rykaczewski, H. Sakurai, Y. Shimizu, D. W. Stacener, T. Sumikama, H. Suzuki, H. Takeda, J. L. Tain,
A. Tarifeño-Saldivia, A. Tolosa-Delgado, V. Vaquero, P. J. Woods, R. Yokoyama, and C. Yuan, “Observation of a µs isomer in 134
49 In85 :Proton-neutron coupling “southeast” of 132
50 Sn82 ,” Phys. Rev. C 100, 011302(R) (2019).
R. Yokoyama, R. Grzywacz, B. C. Rasco, N. Brewer, K. P. Rykaczewski, I. Dillmann, J. L. Tain, S. Nishimura, D. S. Ahn, A. Algora,
J. M. Allmond, J. Agramunt, H. Baba, S. Bae, C. G. Bruno, R. Caballero-Folch, F. Calvino, P. J. Coleman-Smith, G. Cortes, T. Davinson, C. Domingo-Pardo, A. Estrade, N. Fukuda, S. Go, C. J. Griﬃn, J. Ha, O. Hall, L. J. Harkness-Brennan, J. Heideman, T Isobe,
D. Kahl, M. Karny, T. Kawano, L. H. Khiem, T. T. King, G. G. Kiss, A. Korgul, S. Kubono, M. Labiche, I. Lazarus, J. Liang, J. Liu,
G. Lorusso, M. Madurga, K. Matsui, K. Miernik, F. Montes, A. I. Morales, P. Morrall, N. Nepal, R. D. Page, V. H. Phong, M. Piersa,
M. Prydderch, V. F. E. Pucknell, M. M. Rajabali, B. Rubio, Y. Saito, H. Sakurai, Y. Shimizu, J. Simpson, M. Singh, D. W. Stracener,
T. Sumikama, R. Surman, H. Suzuki, H. Takeda, A. Tarifeño-Saldivia, S L. Thomas, A. Tolosa-Delgado, M. Wolińska-Cichocka,
P. J. Woods, and X. X. Xu “Strong one-neutron emission from two-neutron unbound states in β decays of the r-process nuclei 86, 87 Ga,”
Phys. Rev. C 100, 031302(R) (2019).
L. Sinclair, R. Wadsworth, J. Dobaczewski, A. Pastore, G. Lorusso, H. Suzuki, D. S. Ahn, H. Baba, F. Browne, P. J. Davies, P. Doornenbal,
A. Estrade, Y. Fang, N. Fukuda, J. Henderson, T. Isobe, D. G. Jenkins, S. Kubono, Z. Li, D. Lubos, S. Nishimura, I. Nishizuka, Z. Patel,
S. Rice, H. Sakurai, Y. Shimizu, P. Schury, H. Takeda, P. -A. Söderström, T. Sumikama, H. Watanabe, V. Werner, J. Wu, and Z. Y. Xu,“Half-lives of 73 Sr and 76Y and the consequences for the proton dripline,” Phys. Rev. C 100, 044311 (2019).
K. Nakano, Y. Watanabe, S. Kawase, H. Wang, H. Otsu, H. Sakurai, S. Takeuchi, Y. Togano, T. Nakamura, Y. Maeda, D. S. Ahn,
M. Aikawa, S. Araki, S. Chen, N. Chiga, P. Doornenbal, N. Fukuda, T. Ichihara, T. Isobe, S. Kawakami, T. Kin, Y. Kondo, S. Koyama,
T. Kubo, S. Kubono, M. Uesaka, A. Makinaga, M. Matsushita, T. Matsuzaki, S. Michimasa, S. Momiyama, S. Nagamine, M. Niikura,T. Ozaki, A. Saito, T. Saito, Y. Shiga, M. Shikata, Y. Shimizu, S. Shimoura, T. Sumikama, P. A. Söderström, H. Suzuki, H. Takeda,
R. Taniuchi, J. Tsubota, Y. Watanabe, K. Wimmer, T. Yamamoto, and K. Yoshida, “Isotope production in proton-, deuteron-, andcarbon-induced reactions on 93 Nb at 113 MeV/nucleon” Phys. Rev. C 100, 044605 (2019).
H. Wang, H. Otsu, N. Chiga, S. Kawase, S. Takeuchi, T. Sumikama, S. Koyama, H. Sakurai, Y. Watanabe, S. Nakayama, D. S. Ahn,
H. Baba, S. D. Chen, K. Chikaato, M. L. Cortés, N. Fukuda, A. Hirayama, R. Hosoda, T. Isobe, S. Kawakami, Y. Kondo, S. Kubono,
Y. Maeda, S. Masuoka, S. Michimasa, I. Murray, R. Nakajima, T. Nakamura, K. Nakano, M. Nishimura, T. Ozaki, A. Saito, T. Saito,
H. Sato, Y. Shimizu, S. Shimoura, P. -A. Söderström, Y. Soudo, X. H. Sun, J. Suwa, D. Suzuki, H. Suzuki, H. Takeda, M. Takechi,
Y. Togano, T. Tomai, H. Yamada, M. Yasuda, and K. Yoshida, “Enhancement of element production by incomplete fusion reaction withweakly bound deuteron,” Commun. Phys. 2, 78 (2019).
A. Tolosa-Delgado, J. Agramunt, J. L. Tain, A. Algora, C. Domingo-Pardo, A. I. Morales, B. Rubio, A. Tarifeno-Saldivia, F. Calvino,
G. Cortes, N. T. Brewer, B. C. Rasco, K. P. Rykaczewski, D. W. Stracener, J. M. Allmond, R. Grzywacz, R. Yokoyama, M. Singh,
T. King, M. Madurga, S. Nishimura, V. H. Phong, S. Go, J. Liu, K. Matsui, H. Sakurai, G. G. Kiss, T. Isobe, H. Baba, S. Kubono,
N. Fukuda, D. S. Ahn, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, P. A. Soderstrom, M. Takechi, C. G. Bruno, T. Davinson,
C. J. Griﬃn, O. Hall, D. Kahl, P. J. Woods, P. J. Coleman-Smith, M. Labiche, I. Lazarus, P. Morrall, V. F. E. Pucknell, J. Simpson,
S. L. Thomas, M. Prydderch, L. J. Harkness-Brennan, R. D. Page, I. Dillmann, R. Caballero-Folch, Y. Saito, A. Estrade, N. Nepal,
F. Montes, G. Lorusso, J. Liang, S. Bae, J. Ha, B. Moon, the BRIKEN collaboration, “Commissioning of the BRIKEN detector for themeasurement of very exoticβ-delayed neutron emitters,” Nucl. Instrum. Methods Phys. Res. A 925, 133 (2019).
S. Takeuchi, T. Nakamura, M. Shikata, Y. Togano, Y. Kondo, J. Tsubota, T. Ozaki, A. Saito, H. Otsu, H. Wang, H. Sakurai, Y. Watanabe,
S. Kawase, D. S. Ahn, M. Aikawa, T. Ando, S. Araki, S. Chen, N. Chiga, P. Doornenbal, S. Ebata, N. Fukuda, T. Isobe, S. Kawakami,
T. Kin, S. Koyama, S. Kubono, Y. Maeda, A. Makinaga, M. Matsushita, T. Matsuzaki, S. Michimasa, S. Momiyama, S. Nagamine,
K. Nakano, M. Niikura, K. Ogata, T. Saito, Y. Shiga, Y. Shimizu, S. Shimoura, T. Sumikama, Pär-Anders Söderstrom, H. Suzuki,
H. Takeda, R. Taniuchi, M. Uesaka, Y. Watanabe, K. Wimmer, T. Yamamoto, and K. Yoshida, “Coulomb breakup reactions of 93, 94 Zr
in inverse kinematics,” Prog. Theor. Exp. Phys. 2019, 013D02 (2019).
S. Michimasa, J. Hwang, K. Yamada, S. Ota, M. Dozono, N. Imai, K. Yoshida, Y. Yanagisawa, K. Kusaka, M. Ohtake, M. Matsushita,
D. S. Ahn, O. Beliuskina, N. Chiga, K. Chikaato, N. Fukuda, S. Hayakawa, E. Ideguchi, K. Iribe, C. Iwamoto, S. Kawase, K. Kawata,
N. Kitamura, S. Masuoka, H. Miyatake, D. Nagae, R. Nakajima, T. Nakamura, K. Nakano, S. Omika, H. Otsu, H. Sakurai, P. Schrock,H. Shimizu, Y. Shimizu, T. Sumikama, X. Sun, D. Suzuki, H. Suzuki, M. Takaki, M. Takechi, H. Takeda, S. Takeuchi, T. Teranishi,
R. Tsunoda, H. Wang, Y. Watanabe, Y. X. Watanabe, K. Wimmer, K. Yako, H. Yamaguchi, L. Yang, H. Yoshida, and S. Shimoura,“OEDO, the energy-degrading beamline at RI Beam Factory,” Prog. Theor. Exp. Phys. 2019, 043D01 (2019).
J. Hwang, S. Michimasa, S. Ota, M. Dozono, N. Imai, K. Yoshida, Y. Yanagisawa, K. Kusaka, M. Ohtake, D. S. Ahn, O. Beliuskina,
N. Fukuda, C. Iwamoto, S. Kawase, K. Kawata, N. Kitamura, S. Masuoka, H. Otsu, H. Sakurai, P. Schrock, T. Sumikama, H. Suzuki,
M. Takaki, H. Takeda, R. Tsunoda, K. Wimmer, K. Yako, and S. Shimoura, “Angle-tunable wedge degrader for an energy-degrading
RI beamline “, Prog. Theor. Exp. Phys. 2019, 043D02 (2019).
T. Sonoda, I. Katayama, M. Wada, H. Iimura, V. Sonnenschein, S. Iimura, A. Takamine, M. Rosenbusch, T. M. Kojima, D. S. Ahn,
N. Fukuda, T. Kubo, S. Nishimura, Y. Shimizu, H. Suzuki, H. Takeda, M. Tanigaki, H. Tomita, K. Yoshida, and H. Ishiyama, “Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for
high-energy RI beams in the parasitic gas cell,” Prog. Theor. Exp. Phys. 2019, 113D02 (2019).

- 323 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53[Proceedings]
K. Kusaka, “Long term operation of the superconducting triplet quadrupoles with cryocoolers for BigRIPS in-flight separator at RIKEN,”
2019 IOP Conf. Ser.: Mater. Sci. Eng. 502, 012103(2019).

Presentations[International conferences/workshops]
H. Suzuki (oral), “Discovery of 72 Rb & production of proton-rich RI-beams at RIBF,” The International Conference on Proton-Emitting
nuclei (PROCON2019), East Lansing, Michigan, USA, June 3–7, 2019.
N. Fukuda (invited), “Observation of new isotopes at RIKEN RI Beam Factory,” XXXVI Mazurian Lakes Conference on Physics, Piaski,
Poland, September 1–7, 2019.
K. Kusaka (poster), “Long term operation of the superconducting triplet quadrupoles with cryocoolers,” EUCAS2019: 14th European
Conference on Applied Superconductivity, SEC, Glasgow, UK, September 1–5, 2019.
D. S. Ahn (invited), “Status of RI beam production at BigRIPS,” Expert meeting on Next-Generation Fragment Separators 2019, Darmstadt, Germany, September 30–October 2, 2019.
H. Takeda(invited), “Development of various new ion-optics modes at BigRIPS,” Expert meeting on Next-Generation Fragment Separators
2019, Darmstadt, Germany, September 30–October 2, 2019.
N. Fukuda (invited), “Observation of new isotopes at RIKEN RI Beam Factory,” 14th Asia Pacific Physics Conference, Sarawak, Malaysia,
November 17–21, 2019.
N. Fukuda (oral), “Present status of RI production at RIKEN RI Beam Factory and future prospects—RI Production at high energies—,”
JSPS/NRF/NSFC A3 Foresight Program “Nuclear Physics in the 21st Century,” Joint Kickoﬀ Meeting, Kobe, Japan, December 6–7,
2019.

[Domestic conferences/workshops]দຊᠳଡʢ‫ޱ‬಄ൃදʣ, ੢ོത, ߴ໦‫ج‬৳, A. D. Soon, അ৔ल஧, ౻Ԭ޺೭, ෱ా௚थ, ෱੢ெঘ, H. Geissel, Ҵลঘਓ, ൘‫݈ڮ‬ଠ, ೔Լ݈༞, ࡾ໦‫ݠ‬ೋ࿠, ࡾྠւ࠼, Ӭߐ஌จ, ࡕ্गԻ, ਗ਼ਫཅฏ, ୸‫ה‬૱೭, ླ໦޺, ஛ాߒ೭, ాதྑथ, ্ࡔ༑༸, ౉ลचҎ, ໼޲‫ݠ‬ଠ࿠, ༄ᖒળߦ, ٢ాޫҰ, મኍेࡾ, ʮBigRIPS ʹ͓͚Δߴਫ਼౓ύΠதؒࢠ‫ࢠݪ‬෼ޫɾೋॏΨϞϑʵςϥʔ‫ڊ‬େ‫ڞ‬໐୳ࡧ࣮‫ݧ‬ͷ‫ݱ‬ঢ়ʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
S. Masuoka, S. Shimoura, M. Takaki, M. Dozono, C. Iwamoto, K. Kawata, N. Kitamura, M. Kobayashi, S. Michimasa, R. Nakajima,
S. Ota, H. Tokieda, R. Yokoyama, D. S. Ahn, H. Baba, N. Fukuda, T. Harada, E. Ideguchi, N. Imai, N. Inabe, Y. Kondo, T. Kubo,
Y. Maeda, F. M. Marques, M. Matsushita, T. Nakamura, N. Orr, H. Sakai, H. Sato, P. Schrock, L. Stuhl, T. Sumikama, H. Suzuki,
H. Takeda, K. Taniue, T. Uesaka, K. Wimmer, K. Yako, Y. Yamaguchi, Y. Yanagisawa, K. Yoshida, and J. Zenihiro, ʮೋॏՙిަ‫׵‬൓
Ԡ 4 He(8 He, 8 Be) ൓Ԡͷ࠶ଌఆ IIʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
ࡾ໦੖ྤ, தଜོ࢘ (‫ޱ‬಄ൃද), ۙ౻༸հ, N. L. Achouri, T. Aumann, അ৔ल஧, F. Delaunay, P. Doornenbal, ෱ా௚थ, J. Gibelin,
J. Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี, ؆໺େً, S. Kim, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, S. Leblond, J. Lee, M. Marques, ೆํ྄‫ޗ‬, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, தౢৎՅ, த௩ಙ‫ܧ‬, A. Navin, ੢੐࣐࿠, ੜӽॣ, N. A. Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ෢಺૱, ాதོ‫ݾ‬, ௪໺ହ޺, A. G. Tuﬀ, M. Vandebrouck, ถా݈Ұ࿠, ʮՙిަ‫׵‬൓ԠΛ༻͍ͨதੑࢠա৒ඇଋറ֩ 28 F ͷ‫ڀݚ‬ʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
෌ాਸ਼थ (‫ޱ‬಄ൃද), ෢ஐຑ໹, େ௶ོ, ຊؒজ, ాத੟ਉ, ෱ాޫॱ, ླ໦݈, ੢ଜଠथ, ৿‫ޱ‬఩࿕, ҆ಘॱ, A. S. Aimaganbetov, ఱ໺কಓ, ߥ઒༟थ, S. Bagchi, K. H. Behr, N. Burtebayev, ਌੻࿨໻, ైߤ, ౻Ҫ๎໵, ෱ా௚थ, H. Geissel, ງଠ஍, ੕໺णय़, ҏ‫ޒ‬ᖒྋ, ஑ా࠼Ն, Ҵลঘਓ, ழ‫ۢވ‬ඒ, ൘‫݈ڮ‬ଠ, ઘ઒୎࢘, ্Ԭେ‫ى‬, ਆా௚ਓ, Ճ౻Үຏ, I. Kenzhina, Z. Korkulu, Ye. Kuk, ೔Լ݈༞, ࡾ‫࢚جݪ‬, ‫ܙాٶ‬ཧ, ௕ߐେี, தଜᠳ݈, M. Nassurlla, ੢ࣨࠃޫ, ੢௩‫࣏ݡ‬, େᙈॢҰ࿕, େ੢߁հ, େ஛੓༤, Ԧ‫ܙ‬ਔ, খ୔‫ݦ‬, A. Prochazka, ᓎҪതّ, C. Scheidenberger, ਗ਼ਫཅฏ, ਿ‫وݪ‬৴, ୸‫ה‬૱೭, ླ໦৳࢘, ླ໦޺, ஛ాߒ೭, ాத༔ଠ࿠, ాதྑथ,࿨ాଠ࿠, एࢁਗ਼ࢤ, ീ໦ᠳҰ, ࢁ‫وޱ‬೭, ༄‫ే཮ݪ‬, ༄ᖒળߦ, ٢ాޫҰ, T. K. Zholdybayev, ʮSc ಉҐମͷՙిมԽஅ໘ੵଌఆʯ,೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
ಊԂণഢ (‫ޱ‬಄ൃද), ࠓҪ৳໌, ಓਖ਼৽Ұ࿠, ԼӜ‫ڗ‬, େా৾ี, ୸‫ה‬૱೭, ઍլ৴޾, େ௡ल‫ڿ‬, ೖ෦߂ଠ࿠, ଞ ImPACT17-02-01 ίϥϘϨʔγϣϯ, ʮ௿଎ RI ϏʔϜΛ༻͍ͨ 107 Pd ͷཅࢠɾॏཅࢠ༠‫ى‬൓Ԡଌఆʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱
Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
ೖ෦߂ଠ࿠ (‫ޱ‬಄ൃද), ಊԂণഢ, ࠓҪ৳໌, ಓਖ਼৽Ұ࿠, ԼӜ‫ڗ‬, େా৾ี, ୸‫ה‬૱೭, ઍլ৴޾, େ௡ल‫ڿ‬, ࣉ੢ߴ, ଞ ImPACT1702-01 ίϥϘϨʔγϣϯ, ʮ௿଎ RI ϏʔϜΛ༻͍ͨ 93 Zr ͷཅࢠɾॏཅࢠ༠‫ى‬൓Ԡଌఆʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
‫ݪ܀‬ಞࢤ (‫ޱ‬಄ൃද), தଜོ࢘, ۙ౻༸հ, ෢಺૱, ేถ‫و‬ਓ, ᴡ౻ರඒ, ҆ాণ߂, ࢁా‫وܒ‬, ౡా఩࿕, ࡾ໦੖ྤ, দຊਅ༝ࢠ,N. L. Achouri, T. Aumann, അ৔ल஧, F. Delaunay, P. Doornenbal, ෱ా௚थ, J. Gibelin, J. Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี,S. KimD, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, S. Leblond, J. Lee, M. Marques, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, த௩ಙ‫ܧ‬, A. Navin,
N. A. Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ௪໺ହ޺, A. G. Tuﬀ, M. Vandebrouck, ถా݈Ұ࿠, ʮ22 C ͷΫʔϩϯ෼ղ൓Ԡʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
٢ཹ༐‫ى‬, ۙ౻༸հ (‫ޱ‬಄ൃද), தଜོ࢘, N. L. Achouri, T. Aumann, അ৔ल஧, F. Delaunay, P. Doornenbal, ෱ా௚थ, J. Gibelin,
J. Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี, ؆໺େً, S. Kim, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, S. Leblond, J. Lee, M. Marques, ೆํ྄‫ޗ‬, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, தౢৎՅ, த௩ಙ‫ܧ‬, A. Navin, ੢੐࣐࿠, ੜӽॣ, N. A. Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ෢಺૱, ాதོ‫ݾ‬, ௪໺ହ޺, A. G. Tuﬀ, M. Vandebrouck, ถా݈Ұ࿠, ʮ25 O ͷෆม࣭ྔ֩෼ޫʯ, ೔ຊ෺ཧֶձୈ 72 ճ೥࣍େձ, ‫۝‬भେֶ, ෱Ԭ, 2019 ೥ 3 ݄ 14 ೔–17 ೔.
ࡾ໦੖ྤ (‫ޱ‬಄ൃද), ۙ౻༸հ, தଜོ࢘, N. L. Achouri, T. Aumann, അ৔ल஧, F. Delaunay, P. Doornenbal, ෱ా௚थ, Julien Gibelin,
J. Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี, ؆໺େً, S. Kim, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, S. Leblond, J. Lee, M. Marques, ೆํ- 324 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

྄‫ޗ‬, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, தౢৎՅ, த௩ಙ‫ܧ‬, A. Navin, ੢੐࣐࿠, ੜӽॣ, N. A. Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ෢಺૱, ాதོ‫ݾ‬, ௪໺ହ޺, A. G. Tuﬀ, M. Vandebrouck, ถా݈Ұ࿠, ʮՙిަ‫׵‬൓ԠΛ༻͍ͨඇଋറ֩ 28 F ͷ୳ࡧʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17 ೔–20 ೔.
٢ཹ༐‫ޱ( ى‬಄ൃද), ۙ౻༸հ, தଜོ࢘, N. L. Achouri, T. Aumann, അ৔ल஧, F. Delaunay, P. Doornenbal, ෱ా௚थ, J. Gibelin,
J. Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี, ؆໺େً, S. Kim, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, S. Leblond, J. Lee, M. Marques, ೆํ྄‫ޗ‬, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, தౢৎՅ, த௩ಙ‫ܧ‬, A. Navin, ੢੐࣐࿠, ੜӽॣ, N. A. Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ෢಺૱, ాதོ‫ݾ‬, ௪໺ହ޺, A. G. Tuﬀ, M. Vandebrouck, ถా݈Ұ࿠, ʮ25 O ͷෆม࣭ྔ֩෼ޫʯ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17 ೔–20 ೔.
N. Fukuda (oral), “Current and near future BigRIPS DAQ,” RIBFDAQ workshop 2019, RIKEN, Wako, Japan, December 23, 2019.

Press releases
RIKEN ϓϨεൃද (2019.11.19) ϑοૉͱωΦϯͷಉҐ‫ݩ‬ૉͷଘࡏ‫ݶ‬քΛॳΊܾͯఆ—‫֩ࢠݪ‬ͷ஍ਤͷ‫ڥ‬քઢΛ 20 ೥ͿΓʹߋ৽—Ҵลঘਓ, ෱ా௚थ, ‫ٱ‬อහ޾, தଜོ࢘- 325 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Research Instruments GroupSAMURAI Team
1. Abstract

In collaboration with research groups in and outside RIKEN, the team designs, develops and constructs the SAMURAI spectrometer and relevant equipment that are and will be used for reaction experiments using RI beams at RI Beam Factory. The SAMURAI
spectrometer consists of a large superconducting dipole magnet and a variety of detectors to measure charged particles and neutrons.
After the commissioning experiment in March 2012, the team prepared and conducted, in collaboration with researchers in individual experimental groups, the first series of experiments with SAMURAI in May 2012. Then, several numbers of experiments were
well performed until now utilizing the property of SAMURAI. The team also provides a basis for research activities by, for example,
organizing collaboration workshops by researchers who are interested in studies or plan to perform experiments with the SAMURAI
spectrometer.

2. Major Research Subjects

Design, operation, maintenance and improvement of the SAMURAI spectrometer and its related research instruments. Supportand management for SAMURAI-based research programs. Generate future plans for next generation instruments for nuclear reaction
studies.

3. Summary of Research Activity

The current research subjects are summarized as follows:(1) Operation, maintenance and improvement of a large superconducting dipole magnet that is the main component of the SAMURAI spectrometer.
(2) Design, development and construction of various detectors that are used for nuclear reaction experiments using the SAMURAI
spectrometer.
(3) Preparation for planning experiments using SAMURAI spectrometer.
(4) Maintenance and improvement of the SAMURAI beam line.
(5) Formation of a collaboration platform called SAMURAI collaboration.
(6) Preparation for next generation spectrometer for nuclear reaction studies.

Members
Team Leader
Hideaki OTSU
Research & Development Scientist
Mizuki NISHIMURA
Junior Research Associate
Takato TOMAI

List of Publications & Presentations
Publications[Original papers]
A. Revel, O. Sorlin, F. M. Marqués, H. Otsu et al., “Extending the Southern Shore of the Island of Inversion to 28 F,” Phys. Rev. Lett. 124,
152502 (2020).
K. J. Cook, T. Nakamura, Y. Kondo, K. Hagino, H. Otsu et al., “Halo Structure of the Neutron-Dripline Nucleus 19 B,” Phys. Rev. Lett.
124, 212503 (2020).
M. L. Cortes, W. Rodriguez, P. Doornenbal, A. Obertelli, H. Otsu et al., “Shell evolution of N = 40 isotones towards 60 Ca: first spectroscopy of 62 Ti,” Phys. Lett. B 800, 135071 (2020).
Y. L. Sun, A. Obertelli, P. Doornenbal, H. Otsu et al., “Restoration of the natural E(1/2+1 )-E(3/2+1 ) energy splitting in odd-K isotopes
towards N = 40,” Phys. Lett. B 802, 135215 (2020).
S. Chen, J. Lee, P. Doornenbal, A. Obertelli, H. Otsu et al., “Quasifree Neutron Knockout from 54 Ca Corroborates Arising N = 34 Neutron
Magic Number,” Phys. Rev. Lett. 123, 142501 (2019).
A. Corsi, Y. Kubota, J. Casal, H. Otsu et al., “Structure of 13 Be probed via quasi-free scattering,” Phys. Lett. B 797, 134843 (2019).
Y. Kondo, T. Tomai, and T. Nakamura, “Recent progress and developments for experimental studies with the SAMURAI spectrometer,”Nucl. Instrum. Methods Phys. Res. B 463, 173–178 (2020).
L. Stuhl, M. Sasano, H. Otsu et al., “Study of spin-isospin responses of radioactive nuclei with the background-reduced neutron” spectrometer, PANDORA,” Nucl. Instrum. Methods Phys. Res. B 463, 189–194 (2020).
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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Y. Togano, T. Nakamura, Y. Kondo, H. Otsu et al., “New γ–ray detector CATANA for in-beam γ–ray spectroscopy with fast RI beams,”
Nucl. Instrum. Methods Phys. Res. B 463, 195–197 (2020).

[Proceedings]
M. Kurata-Nishimura et al., “Experimental study of nuclear equation of state using heavy ion collisions at RIKEN-RIBF,” Proc. 15th Int.
Symp. Origin of Matter and Evolution of Galaxies (OMEG15) JPS Conf. Proc. 31, (2020), p. 011023.
J. Gibelin et al., “Boron isotopes at the drip-line: 19 B,” Proc. of the 22nd Int. Conf. on Few-Body Problems in Physics Springer Proceedings in Physics 238 (2020), p. 103.
B. Monteagudo et al., “Structure of Beryllium isotopes beyond the neutron dripline,” Proc. of the 22nd Int. Conf. on Few-Body Problemsin Physics Springer Proceedings in Physics 238 (2020), p. 331.
Z. H. Yang et al., “Study of multi-neutron systems with the SAMURAI spectrometer,” Proc. of the 22nd Int. Conf. on Few-Body Problemsin Physics Springer Proceedings in Physics 238 (2020), p. 529.
A. I. Chilug, et al., “Study of the 9 C breakup through NP1412-SAMURAI29R1 experiment,” Carpathian Summer School of Physics 2018
(CSSP18), Sinaia, Romania, AIP Conference Proceedings 2076, 060001 (2019).

Presentations[International conferences/workshops]
M. Kurata–Nishimura, “Experimental study of nuclear equation of state using heavy ion collisions at RIKEN-RIBF,” The 15th International Symposium on Origin of Matter and Evolution of Galaxies, Kyoto, July 2–5, 2019.
M. Kurata–Nishimura, “Recent results of collective flow at neutron rich Sn+Sn collisions with 270 MeV/u,” 9th International Symposium
on Nuclear Symmetry Energy (NuSYM 2019), Da Nang, Vietnam, October 2–5, 2019.
T. Nakamura, “Recent progress of spectroscopic studies of nuclei near and beyond the neutron drip line,” Thirty Eighth International
Workshop on Nuclear Theory, Rila Mountains, Bulgaria, June 23–29, 2019.
Y. Kondo, “Spectroscopy of Oxygen isotopes beyond the neutron drip line,” Gordon Research Conference, “Exploring simple structural
patterns and the dynamics of nuclei,” New London, NH, US, June 16–21, 2019.
K. J. Cook, “Nuclear structure at the neutron drip-line: determining the halo nature of 19 B using coulomb breakup,” Gordon Research
Conference, “Exploring simple structural patterns and the dynamics of nuclei,” New London, NH, US, June 16–21, 2019.
Y. Kondo, “Spectroscopy of unbound nuclei towards the possible doubly magic nucleus 28 O,” 27th International Nuclear Physics Conference, Glasgow, UK, July 29–August 2, 2019.
T. Nakamura, “Spectroscopy of neutron-drip-line nuclei using SAMURAI at RIBF,” 27th International Nuclear Physics Conference,
Glasgow, UK, July 29–August 2, 2019.
T. Tomai, “Observation of excited states of 31 Ne using nuclear breakup reaction,” 27th International Nuclear Physics Conference, Glasgow,
UK, July 29–August 2, 2019.
T. Nakamura, “SAMURAI at RIBF: recent progress and near-future perspectives,” RIBF USERS Meeting 2019, RIKEN, Wako, Japan,
September 3–4, 2019.
T. Nakamura, “Multi-neutron clusters,” 4th International Workshop on Quasi-Free Scattering with Radioactive-Ion Beams, Maresias,
Brazil, October 9–13, 2019.
T. Nakamura, “Study of nuclear structure with radioactive beams,” WE-Heraeus Summer School on: Nuclear Physics in Astrophysics,
Heidelberg, Germany, September 9–16, 2019.
T. Nakamura, “Exploration of neutron drop line nuclei at RIBF,” 14th Asia-Pacific Physics Conference, Borneo Convention Centre
Kuching, Sarawak, Malaysia, November 17–22, 2019.
T. Nakamura, “Experiments on neutron-rich nuclei at SAMURAI at RIBF for astrophysics,” Workshop on “Origin of elements and cosmic
evolution: From big-bang to supernovae and mergers,” Beihang University, Beijing China, November 27–29, 2019.
T. Nakamura, “Exotic nuclei for investigating hierarchical structure of matter,” International Symposium on Clustering as a Window on
the Hierarchical Structure of Quantum Systems (CLUSHIQ2020), Beppu, Japan, January 23–24, 2020.
T. Nakamura, “Coulomb breakup of halo nuclei,” Japan-France Joint Workshop Clusters in Quantum Systems: From Atoms to Nuclei
and Hadrons, Fukuoka, Japan, January 27–31, 2020.
T. Nakamura, “Study of exotic nuclei along the neutron drip line and beyond,” Vth Topical Workshop on Modern Aspects of Nuclear
Structure, Bormio, Italy, February 4–9, 2020.
N. A. Orr, “High-energy direct reaction studies of light, nuclei beyond the neutron dripline,” 27th International Nuclear Physics Conference, Glasgow, UK, July 29–August 2, 2019,
N. A. Orr, “Direct reaction studies with high-energy radioactive beams of light nuclei beyond the neutron dripline,” Workshop on Challenges in Direct Nuclear Reactions, Beijing, China, August 19–21, 2019.
N. A. Orr, “Direct reaction studies of light neutron-rich nuclei beyond the dripline,” CENuM-RULiC Joint Workshop on Extreme Nuclear
States and Reactions, Daejeon, South Korea, October 31–November 2, 2019.
F. M. Marqués, “Probing nuclei with (too) many neutrons,” Gordon Research Conference, “Exploring simple structural patterns and the
dynamics of nuclei,” New London, NH, US, June 16–21, 2019.
F. M. Marqués, “The extremes of neutron richness,” Pisa Summer School—Rewriting Nuclear Physics Textbooks: One More Step Forward, Pisa, Italy, July 22–26, 2019.
F. M. Marqués, “Exotic structures in exotic nuclei,” 24th European Conference on Few-Body Problems in Physics, Guildford, UK, 2–6- 327 -

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September 2019.
F. M. Marqués, “Two-neutron emission and related phenomena,” Workshop GDR RESANET—Nuclear Structure under Extreme Conditions, Caen, France, December 9–10, 2019.
J. Gibelin, “Neutron-rich boron isotopes at and beyond the drip line,” Japan-France Joint Workshop Clusters in Quantum Systems: From
Atoms to Nuclei and Hadrons, Fukuoka, Japan, January 27–31, 2020.
C. Lenain, “Search for Hydrogen 7 and its 4 neutron decay at SAMURAI,” Japan-France Joint Workshop Clusters in Quantum Systems:
From Atoms to Nuclei and Hadrons, Fukuoka, Japan, January 27–31, 2020.
M. Duer, “Study of the 8 He(p, pα)4n reaction,” International Workshop on Quasi-free Scattering with Radioactive Beams Maresias,
Brazil, QFS-RB19, October 13–18, 2019.
M. Knösel, “Precise measurement of the neutron-neutron scattering length,” International Workshop on Quasi-free Scattering with Radioactive Beams QFS-RB19, Maresias, Brazil, October 13–18, 2019.
C. Lehr, “Results from NeuLAND @ SAMURAI and the low-energy dipole response of 6, 8 He,” NUSTAR Annual Meeting, GSI Darmstadt, Germany, March 2–6, 2020,[SAMURAI International Collaboration Workshop 2019, Rikkyo University, Tokyo, Japan, August 30–31, 2019.]

Y. L. Sun et al., “STRASSE: a silicon tracker project for quasi free scattering at RIBF.”
T. Nakamura et al., “Development of high-granularity neutron detector array HIME.”
T. Aumann et al., “Status of TUDa funding application for construction of HIME and future experiments at SAMURAI.”
D. Rossi et al., “Invariant-mass spectroscopy at the low-Z shore of the island of inversion.”
H, Chae et al., “Study of unbound nuclei 33 Ne via one-proton knockout reactions.”
Sonja Storck, et al., “Analysis update on the lifetime measurement of the 26 O g.s. at SAMURAI.”
M. Duer, et al., “Analysis of the 8 He(p, pα)4n.”
Z. Yang, et al., “Quasi-free (p,pn) reaction with Borromean nuclei 11 Li,14 Be, and 17 B.”
V. Panin et al., “Status report of S24 experiment: investigation of unbound states in neutron-deficient 66 Se.”
H. Otsu et al., “HI-α invariant mass spectroscopy.”
S. Kim et al., “Study of unbound excited states in 17 C.”
Y. Hirai et al., “Study of Gamow-Teller transition in neutron-rich 11 Li’.
T. Pohl et al., “Analysis status of S31: probing isospin dependence of nucleon correlations using (p, pN) reaction.”
T. Motobayashi et al., “Nuclear breakup and coulomb dissociation of 9 C nucleus studied at RIBF RIKEN.”
T. Isobe et al., “Experimental study of density dependent symmetry energy at RIBF-SPiRIT.”
Z. H. Yang et al., “Status report of s034: study of 7 H and the tetraneutron using 8 He(p, 2p) reaction.”
P. Li et al., “Cluster structure of neutron-rich Beryllium isotopes investigated by cluster quasi-free scattering reaction.”Y. Togano et al., “Status report of dipole strength measurement performed in S09 and ImPACT.”
C. Lehr et al., “Analysis update on the low-energy dipole response of the halo nuclei 6, 8 He.”
J. Tanaka et al., “Search for preformed-alpha particles via alpha-knockout reaction from alpha-decay nuclei.”
N. A. Orr et al., “Status of NEBULA-Plus and possible future experiments.”
Y. KONDO et al., “Status report of the SAMURAI21 experiment.”
H. Wang et al., “Study on tensor correlation in neutron-rich nuclei via (p, pd) reaction.”[Domestic conferences/workshops]
தଜོ࢘, ʮΤΩκνοΫ֩ࢠଟମ‫Ͱܥ‬ඥղ͘෺࣭ͷ֊૚ߏ଄ʯ, ୈೋճΫϥελʔ֊૚ྖҬ‫ڀݚ‬ձ, ౦‫ۀ޻ژ‬େֶ, ౦‫ژ‬, 2019 ೥ 5
݄ 31–6 ݄ 1 ೔.
҆ా੟, ʮμΠχϡʔτϩϯ୳ࡧͷͨΊͷߴਫ਼ࡉதੑࢠ‫ݕ‬ग़‫ث‬ͷ։ൃ-IIʯ, 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
ࡾ໦੖ྤ, ʮՙిަ‫׵‬൓ԠΛ༻͍ͨඇଋറ֩ 28F ͷ୳ࡧʯ, 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
ౡా఩࿕, ʮதੑࢠա৒ඇଋറ֩ 30F ͷ֩෼ޫʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
٢ཹ༐‫ى‬, ʮ25 O ͷෆม࣭ྔ֩෼ޫʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձୈ 75 ճ೥࣍େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
தଜོ࢘, ʮଟதੑࢠΫϥελʔ୳ࡧͷͨΊͷ൓௓ཅࢠ‫ݕ‬ग़‫ ث‬CATANA/STRASSEʯ, ৽ֶज़ྖҬʮΫϥελʔ֊૚ʯʮྔࢠϏʔϜԠ༻ʯ߹ಉ‫ݕ‬ग़‫ث‬ϫʔΫγϣοϓ, ౦๺େֶ, ઋ୆, 2019 ೥ 9 ݄ 20–21 ೔.
҆ా੟, “Development of the neutron detector array with high granularity (HIME) for dineutron correlation measurement,” ৽ֶज़ྖҬ‫ڀݚ‬ʮྔࢠΫϥελʔͰಡΈղ͘෺࣭ͷ֊૚ߏ଄ʯεΫʔϧ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2020 ೥ 3 ݄ 2–4 ೔.
ւ࿝໊௚थ, ʮෆ҆ఆ֩ͷ४஄ੑࢄཚଌఆ༻ཅࢠ‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ৽ֶज़ྖҬ‫ڀݚ‬ʮྔࢠΫϥελʔͰಡΈղ͘෺࣭ͷ֊૚ߏ଄ʯεΫʔϧ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2020 ೥ 3 ݄ 2–4 ೔.
ߴ‫߁ڮ‬ฏ, ʮߴ෼ղೳதੑࢠ‫ݕ‬ग़‫ ث‬HIME ͷ։ൃʯ, ৽ֶज़ྖҬ‫ڀݚ‬ʮྔࢠΫϥελʔͰಡΈղ͘෺࣭ͷ֊૚ߏ଄ʯεΫʔϧ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2020 ೥ 3 ݄ 2–4 ೔.
ేถ‫و‬ਓ, ʮม‫ܗ‬༠Ҿ‫ܕ‬ϋϩʔ֩ 31Ne ͷඇଋറྭ‫ى‬ঢ়ଶͷ୳ࡧʯ, ৽ֶज़ྖҬ‫ڀݚ‬ʮྔࢠΫϥελʔͰಡΈղ͘෺࣭ͷ֊૚ߏ଄ʯ
εΫʔϧ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2020 ೥ 3 ݄ 2–4 ೔.
ᴡ౻ರඒ, ʮதੑࢠա৒ϔϦ΢ϜಉҐମͷΫʔϩϯ෼ղ൓Ԡʯ, ৽ֶज़ྖҬ‫ڀݚ‬ʮྔࢠΫϥελʔͰಡΈղ͘෺࣭ͷ֊૚ߏ଄ʯεΫʔϧ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2020 ೥ 3 ݄ 2–4 ೔.
ᴡ౻ರඒ, ʮதੑࢠա৒ϔϦ΢ϜಉҐମͷΫʔϩϯ෼ղ൓Ԡʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 03 ݄

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16–19 ೔.

[Poster presentation]
S. Storck, “Lifetime measurement of the 26 O g.s. at SAMURAI,” International Nuclear Physics Conference, Glasgow, UK, INPC2019,
July 29–August 2, 2019.

AwardsJ. Kahlbow, Giersch Award for Outstanding Doctoral Thesis 2019, 2019.

Press releases
O. Sorlin and F. M. Marqués, “L’oxygène-28 n’aurait pas la stabilité que la théorie lui prédit,” IN2P3-CNRS: Actualités - April 27, 2020,
https://in2p3.cnrs.fr/fr/cnrsinfo/loxygene-28-naurait-pas-la-stabilite-que-la-theorie-lui-predit .
Doornenbal Pieter, ᓎҪതّ, ʮ৽ຐ๏਺ 34 ͷ৽ͨͳূ‫—ڌ‬தੑࢠϊοΫΞ΢τ൓ԠͰ୳ΔΧϧγ΢Ϝ-54 ͷด֪ߏ଄—ʯ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 10 ݄ 18 ೔.

Doctor theses
B. Monteagudo, “Structure and neutron decay of the unbound Beryllium isotopes 15, 16 Be,” Université de Caen Normandie, November
2019.
J. Kahlbow, “The low-Z shore of the island of inversion: invariant-mass spectroscopy of the heavy fluorine isotopes 29 F∗ & 30 F at
SAMURAI with NeuLAND,” Technische Universität Darmstadt, 2019.

Master theses
M. Knösel, “Investigation of the dineutron system via quasi-free He-4-knockout reactions at He-6,” Technische Universität Darmstadt,
2019.
ࡾ໦੖ྤ, ʮՙిަ‫׵‬൓ԠΛ༻͍ͨඇଋറ֩ 28 F ͷ‫ڀݚ‬ʯ, ౦‫ۀ޻ژ‬େֶཧֶӃ෺ཧֶ‫ܥ‬.
ౡా఩࿕, ʮதੑࢠա৒ͳඇଋറϑοૉಉҐମͷ‫ڀݚ‬ʯ, ౦‫ۀ޻ژ‬େֶཧֶӃ෺ཧֶ‫ܥ‬.
‫ݪ܀‬ಞࢤ, ʮ22 C ͷΫʔϩϯ෼ղ൓Ԡʯ, ౦‫ۀ޻ژ‬େֶཧֶӃ෺ཧֶ‫ܥ‬.

Bachelor thesesߴ‫߁ڮ‬ฏ, ʮߴ෼ղೳதੑࢠ‫ݕ‬ग़‫ ث‬HIME ͷ։ൃʯ, ౦‫ۀ޻ژ‬େֶ.
ւ࿝໊௚थ, ʮෆ҆ఆ֩ͷ४஄ੑࢄཚଌఆ༻ཅࢠ‫ݕ‬ग़‫ث‬ͷ։ൃʯ, ౦‫ۀ޻ژ‬େֶ.

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Research Facility Development Division
Research Instruments Group
Computing and Network Team
1. Abstract
This team is in charge of development, management and operation of the computing and network environment, mail and information servers and data acquisition system and management of the information security of the RIKEN Nishina Center.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Development, management and operation of the general computing servers
Development, management and operation of the mail and information servers
Development, management and operation of the data acquisition system
Development, management and operation of the network environment
Management of the information security

3. Summary of Research Activity
This team is in charge of development, management and operation of the computing and network environment, mail and information servers and data acquisition system and management of the information security. The details are described elsewhere in thisprogress report.
(1) Development, management and operation of the general computing servers
We are operating Linux/Unix NIS/NFS cluster system for the data analysis of the experiments and general computing. This
cluster system consists of eight computing servers with 64 CPU cores and totally 200 TB RAID of highly-reliable Fibre-channelinterconnection. Approximately 700 user accounts are registered on this cluster system. We are adopting the latest version of the
Scientific Linux (X86 64) as the primary operating system, which is widely used in the accelerator research facilities, nuclear physics
and high-energy physics communities in the world.
(2) Development, management and operation of the mail and information servers
We are operating RIBF.RIKEN.JP server as a mail/NFS/NIS server. This server is a core server of RIBF Linux cluster system.
Postfix has been used for mail transport software and dovecot has been used for imap and pop services. These software packages
enable secure and reliable mail delivery. Sophos Email Security and Control (PMX) installed on the mail front-end servers whichtags spam mails and isolates virus-infected mails. The probability to identify the spam is approximately 95–99%. We are operating
several information servers such as Web servers, Integrated Digital Conference (INDICO) server, Wiki servers, Groupware servers,
Wowza streaming servers. We have been operating approximately 70 units of wireless LAN access points in RNC. Almost the entire
radiation-controlled area of the East Area of RIKEN Wako campus is covered by wireless LAN for the convenience of experiments
and daily work.
(3) Development, management and operation of the data acquisition system
We have developed the standard data-acquisition system named as RIBFDAQ. This system can process up to 40 MB/s data. By
using crate-parallel readout from front-end systems such as CAMAC and VME, the dead time could be minimized. To synchronize theindependent DAQ systems, the time stamping system has been developed. The resolution and depth of the time stamp are 10 ns and48 bits, respectively. This time stamping system is very useful for beta decay experiments such as EURICA, BRIKEN and VANDLE
projects. One of the important tasks is the DAQ coupling, because detector systems with dedicated DAQ systems are transported to
RIBF from foreign facilities. In case of SAMURAI Silicon (NSCL/TUM/WUSTL), the readout system is integrated into RIBFDAQ.
The projects of MUST2 (GANIL), MINOS (CEA Saclay), NeuLAND (GSI) and TRB3 (TUM) cases, data from their DAQ systems
are transferred to RIBFDAQ and merged online. For SPIRIT (RIKEN/GANIL/CEA Saclay/NSCL), RIBFDAQ is controlled fromthe NARVAL-GET system that is a large-scale signal processing system for the time projection chamber. EURICA (GSI), BRIKEN(GSI/Univ. Liverpool/IFIC), VANDLE (UTK) and OTPC (U. Warsaw) projects, we adopt the time stamping system to apply individual
trigger for each detector system. In this case, data are merged in oﬄine. In addition, we are developing intelligent circuits based on
FPGA. General Trigger Operator (GTO) is an intelligent triggering NIM module. Functions of “common trigger management,” “gateand delay generator,” “scaler” are successfully implemented. The trigger system in BigRIPS DAQ is managed by 5 GTO modules. To
improve the data readout speed of VME system, we have successfully developed the MPV system which is a parallel readout extensionof the VME system. Data readout sequence is completely parallelized that helps to improve the DAQ deadtime. Thanks to the MPV
system, now the DAQ system in RIBF is 10 times faster than in 2007.
(4) Development, management and operation of the network environment
We have been managing the network environment collaborating with Information Systems Division in RIKEN. All the Ethernet
ports of the information wall sockets are capable of the Gigabit Ethernet connection (10/100/1000 BT). In addition, some 10 Gbps
networks port has been introduced to RIBF experimental area. Approximately 70 units of wireless LAN access points have been
installed to cover the almost entire area of Nishina Center.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53(5) Management of the information security
It is essential to take proper information security measures for information assets. We are managing the information security of
Nishina Center collaborating with Information Systems Division in RIKEN.

Members
Team Leader
Hidetada BABA
Research/Technical Scientist
Yasushi WATANABE (Senior Research Scientist)
Junior Research Associate
Fumiya GOTO
Special Temporary Research Scientist
Takashi ICHIHARA

List of Publications & Presentations
Presentations[International Conferences/Workshops]
H. Baba, “MOCO and MPV/cumputing infrastructure at RIBF, HOKUSAI and U-Tokyo/current and near future BigRIPS DAQ,” RIBFDAQ Workshop, Wako, Japan, December 23, 2019.

[Domestic Conferences/Workshops]
H. Baba, “RIBF DAQ,” SAMURAI International Collaboration Workshop, Toshima, Japan, August 30–31, 2019.
‫ޙ‬౻จ໵ (ΦϯϥΠϯൃදʣ, ʮMTV ࣮‫ݧ‬ͷใࠂ 2ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
അ৔ल஧ (ΦϯϥΠϯൃදʣ, ʮฒྻԽ VME όεʹΑΔ DAQ ͷߴ଎Խʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020
೥ 3 ݄ 16–19 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Research Facility Development Division
Research Instruments Group
Detector Team
1. Abstract

This team is in charge of development, fabrication, and operation of various detectors used for nuclear physics experiments at
RIBF. Our current main mission is maintenance and improvement of detectors which are used at BigRIPS separator and its succeeding
beam lines for beam diagnosis and particle identification of RI beams. We are also engaged in R&D of new detectors that can be used
for higher-intensity RI beams. In addition, we are doing the R&D which uses the pelletron accelerator together with other groups.

2. Major Research Subjects

Development, fabrication, and operation of various detectors for nuclear physics experiments, including beam-line detectors which
are used for the production and delivery of RI beams (beam diagnosis and particle identification). R&D which uses the pelletron
accelerator.

3. Summary of Research Activity

The current research subjects are summarized as follows:(1) Maintenance and improvement of the beam-line detectors which are used at BigRIPS separator and its succeeding beam lines.
(2) Development of new beam-line detectors with radiation hardness and tolerance for higher counting rates.
(3) Management of the pelletron accelerator and R&D which uses the pelletron.

Members
Team Leader
Hiromi SATO
Research/Technical Scientist
Tokihiro IKEDA (Senior Research Scientist)
Special Temporary Employee
Manabu HAMAGAKIVisiting Scientist
Takeshi KOIKE (Tohoku University)
Student Trainees
Shunya KAWAMURA (Toho University)
Masaya SAKAI (University of Tokyo)
Kento TAKEMOTO (University of Tokyo)

Yuka HIKIMA (Toho University)
Mitsumasa MORI (Toho University)

List of Publications & Presentations
Publications[Original papers]
D. S. Ahn, N. Fukuda, H. Geissel, N. Inabe, N. Iwasa, T. Kubo, K. Kusaka, D. J. Morrissey, D. Murai, T. Nakamura, M. Ohtake, H. Otsu,
H. Sato, B. M. Sherrill, Y. Shimizu, H. Suzuki, H. Takeda, O. B. Tarasov, H. Ueno, Y. Yanagisawa, and K. Yoshida, “Location of theneutron dripline at fluorine and neon,” Phys. Rev. Lett. 123, 212501 (2019).
H. Wang, H. Otsu, N. Chiga, S. Kawase, S. Takeuchi, T. Sumikama, S. Koyama, H. Sakurai, Y. Watanabe, S. Nakayama, D. S. Ahn,
H. Baba, S. D. Chen, K. Chikaato, M. L. Cortes, N. Fukuda, A. Hirayama, R. Hosoda, T. Isobe, S. Kawakami, Y. Kondo, S. Kubono,
Y. Maeda, S. Masuoka, S. Michimasa, I. Murray, R. Nakajima, T. Nakamura, K. Nakano, M. Nishimura, T. Ozaki, A. Saito, T. Saito,
H. Sato, Y. Shimizu, S. Shimoura, P. -A. Söderström, Y. Soudo, X. H. Sun, J. Suwa, D. Suzuki, H. Suzuki, H. Takeda, M. Takechi,
Y. Togano, T. Tomai, H. Yamada, M. Yasuda, and K. Yoshida, “Enhancement of element production by incomplete fusion reaction withweakly bound deuteron,” Commun. Phys. 2, 78 (2019).
A. Corsi, Y. Kubota, J. Casal, M. Gomez-Ramos, A. M. Moro, G. Authelet, H. Baba, C. Caesar, D. Calvet, A. Delbart, M. Dozono,
J. Feng, F. Flavigny, J. -M. Gheller, J. Gibelin, A. Giganon, A. Gillibert, K. Hasegawa, T. Isobe, Y. Kanaya, S. Kawakami, D. Kim,
Y. Kiyokawa, M. Kobayashi, N. Kobayashi, T. Kobayashi, Y. Kondo, Z. Korkulu, S. Koyama, V. Lapoux, Y. Maeda, F. M. Marques,
T. Motobayashi, T. Miyazaki, T. Nakamura, N. Nakatsuka, Y. Nishio, A. Obertelli, A. Ohkura, N. A. Orr, S. Ota, H. Otsu, T. Ozaki,
V. Panin, S. Paschalis, E. C. Pollacco, S. Reichert, J. -Y. Rousse, A. T. Saito, S. Sakaguchi, M. Sako, C. Santamaria, M. Sasano,
H. Sato, M. Shikata, Y. Shimizu, Y. Shindo, L. Stuhl, T. Sumikama, Y. L. Sun, M. Tabata, Y. Togano, J. Tsubota, T. Uesaka, Z. H. Yang,
J. Yasuda, K. Yoneda, and J. Zenihiro, “Structure of 13 Be probed via quasi-free scattering,” Phys. Lett. B 797, 134843 (2019).

[Proceedings]- 332 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

M. Ohno, T. Irimatsugawa, Y. Miura, H. Takahashi, T. Ikeda, C. Otani, M. Sakama, and N. Matsufuji, “Calorimetry of heavy charged
particle by superconducting transition-edge sensor,” Journal of Low Temperature Physics 193, 1222–1227 (2018).
R. Smith, M. Ohno, Y. Miura, N. Nakada, Y. Mitsuya, H. Takahashi, T. Ikeda, C. Otani, M. Sakama, N. Matsufuji, T. Irimatsugawa,
S. Kohjiro, H. Yamamori, and F. Hirayama, “Microcalorimetry of carbon ion beam for medical treatment by transition edge sensor,”
Journal of Low Temperature Physics 199, 1012–1017 (2020).
T. Ikeda, M. Ikekame, Y. Hikima, M. Mori, S. Kawamura, T. Minowa, and W. -G. Jin, “Profile measurements of MeV ion microbeams
in atmosphere extracted from single tapered glass capillaries with an end window,” Nucl. Instrum. Methods Phys. Res. B 470, 42–47(2020).
T. Sumikama, T. Kubo, N. Fukuda, D. S. Ahn, H. Takeda, Y. Shimizu, H. Suzuki, N. Inabe, D. Murai, H. Sato, K. Kusaka, Y. Yanagisawa,
M. Ohtake, and K. Yoshida, “First success of RI-beam separation and particle identification for nuclei with atomic number Z > 82 at
RIKEN RI beam factory,” Nucl. Instrum. Methods Phys. Res. B 463, 237–240 (2020).

Presentations[International conferences/workshops]
T. Ikeda, M. Ikekame, Y. Hikima, M. Mori, T. Kawamura, T. Minowa, and W. -G. Jin (oral), “Profile measurements of MeV ion microbeams in atmosphere extracted from single tapered glass capillary with an end window,” 13th European Conference on Accelerators
in Applied Research and Technology (ECAART13), Split, Croatia, May 5–10, 2019.
M. Mori, T. Kawamura, T. Ikeda, T. Minowa, and W. -G. Jin (poster), “Profile measurement of laser microbeam produced by glass
capillaries : tilting dependence,” 24th Optoelectronics and Communications Conference/International Conference on Photonics in
Switching and Computing 2019 (OECC/PSC 2019), Fukuoka, Japan, July 7–11, 2019.
R. Smith, M. Ohno, Y. Miura, N. Nakata, H. Takahashi, Y. Mitsuya, N. Matsufuji, M. Sakama, T. Ikeda, T. Irimatsugawa, S. Koujiro,
H. Yamamori, F. Hirayama, and C. Otani (poster), “Microcalorimetry of carbon ion beam for medical treatment by transition edge
sensor,” 18th International Workshop on Low Temperature Detectors (LTD-18), Milano, Italy, July 22–26, 2019.
T. Ikeda, M. Ikekame, Y. Hikima, M. Mori, T. Kawamura, T. Minowa, and W. -G. Jin (poster), “Measurement of proton microbeam
profiles in atmosphere produced by single tapered glass capillary optics with an end window,” International Conference on Photonic,
Electronic and Atomic Collisions (ICPEAC2019), Deauville, France, July 23–30, 2019.
T. Kawamura, T. Ikeda, M. Mori, and W. -G. Jin (poster), “Development of UV-laser microbeam cell irradiation system by glass capillary
optics : estimation of density enhancement,” 16th International Congress of Radiation Research (ICRR2019), Manchester, UK, August
25–29, 2019.
Y. Hikima, T. Ikeda, M. Ikekame, M. Mori, T. Kawamura, and W. -G. Jin (poster), “Fine structure evaluation by pattern recognition for ion
microbeam extracted from tapered glass capillary optics,” 23rd International Workshop on Inelastic Ion-Surface Collisions (IISC-23),
Matsue, Japan, November 17–22, 2019.

[Domestic conferences/workshops]
஑ా࣌ߒ, ඿ֶ֞, ࠤ౻޿ւ (‫ޱ‬಄ൃද), ʮཧԽֶ‫͚͓ʹॴڀݚ‬ΔλϯσϜՃ଎‫ث‬ͷ‫ݱ‬ঢ়ʢ2018–2019 ೥౓ʣʯ, ୈ 32 ճλϯσϜՃ଎‫ͦͼٴث‬ͷपลٕज़ͷ‫ڀݚ‬ձ, ਆ‫ށ‬େֶ, ਆ‫ށ‬, 2019 ೥ 7 ݄ 5–6 ೔.
ञҪխ࠸, ஑ా࣌ߒ, ࣲా३࢙, ஛ຊ݈ਓ, ্ࡔॆ (ϙελʔ), ʮα ઢ࣏ྍͷͨΊͷ He ΠΦϯϏʔϜ DNA রࣹ෼ੳͷ‫ڀݚૅج‬ʯ, ୈ
16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019 ೥ 7 ݄ 31 ೔–8 ݄ 3 ೔.
஑ా࣌ߒ (‫ޱ‬಄ൃද), ʮϑλ෇ΨϥεΩϟϐϥϦʔʹΑΔ MeV ΠΦϯϚΠΫϩϏʔϜরࣹͰੜͨ͡ࡉ๔֩಺ΠΦϯτϥοΫͷղੳʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ‫ذ‬ෞେֶ, ‫ذ‬ෞ, 2019 ೥ 9 ݄ 10–13 ೔.
ञҪխ࠸, ஑ా࣌ߒ, ࣲా३࢙, ஛ຊ݈ਓ, ্ࡔॆ (‫ޱ‬಄ൃද), ʮα ઢ࣏ྍͷͨΊͷ He ΠΦϯϚΠΫϩϏʔϜ DNA রࣹ෼ੳͷ‫ૅج‬‫ڀݚ‬ʯ, ೔ຊ‫ֶྗࢠݪ‬ձ 2019 ೥ळͷେձ, ෋ࢁେֶ, ෋ࢁ, 2019 ೥ 9 ݄ 11–13 ೔.
ࡾ໦੖ྤ, ۙ౻༸հ, தଜོ࢘, Nadia Lynda Achouri, Thomas Aumann, അ৔ल஧, Franck Delaunay, Pieter Doornenbal, ෱ా௚थ, Julien
Gibelin, Jongwon Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี, ؆໺େً, Sunji Kim, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, Sylvain Leblond,
Jenny Lee, Miguel Marques, ೆํ྄‫ޗ‬, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, தౢৎՅ, த௩ಙ‫ܧ‬, Alahari Navin, ੢੐࣐࿠, ੜӽॣ, Nigel Andrew Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ෢಺૱, ాதོ‫ݾ‬, ௪໺ହ޺, Adam
Garry Tuﬀ, Marine Vandebrouck, ถా݈Ұ࿠ (‫ޱ‬಄ൃද), ʮՙిަ‫׵‬൓ԠΛ༻͍ͨඇଋറ֩ 28 F ͷ୳ࡧʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
٢ཹ༐‫ى‬, ۙ౻༸հ, தଜོ࢘, Nadia Lynda Achouri, Thomas Aumann, അ৔ल஧, Franck Delaunay, Pieter Doornenbal, ෱ా௚थ, Julien
Gibelin, Jongwon Hwang, Ҵลঘਓ, ү෦஧ত, ُాେี, ؆໺େً, Sunji Kim, খྛ৴೭, খྛढ़༤, ‫ٱ‬อහ޾, Sylvain Leblond,
Jenny Lee, Miguel Marques, ೆํ྄‫ޗ‬, ຊྛಁ, ଜҪେ஍, ଜ্఩໵, ෢౻‫ۏ‬ඒ, தౢৎՅ, த௩ಙ‫ܧ‬, Alahari Navin, ੢੐࣐࿠, ੜӽॣ, Nigel Andrew Orr, େ௡ल‫ڿ‬, ࠤ౻޿ւ, ࠤ౻ًٛ, ਗ਼ਫཅฏ, ླ໦޺, ߴ‫ݡڮ‬ਓ, ஛ాߒ೭, ෢಺૱, ాதོ‫ݾ‬, ௪໺ହ޺, Adam
Garry Tuﬀ, Marine Vandebrouck, ถా݈Ұ࿠ (‫ޱ‬಄ൃද), ʮ25 O ͷෆม࣭ྔ֩෼ޫʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
஑ా࣌ߒ, ࠤ౻޿ւ (‫ޱ‬಄ൃද), ʮλϯσϜՃ଎‫ʹث‬ΑΔΩϟϐϥϦʔϚΠΫϩϏʔϜͷੜ੒ͱԠ༻ʯ, ୈ 80 ճԠ༻෺ཧֶձळ‫ق‬ֶज़ߨԋձ, ๺ւಓେֶ, ࡳຈ, 2019 ೥ 9 ݄ 18–21 ೔.
εϛεϥΠΞϯ, େ໺խ࢙, ߴ‫ߒڮ‬೭, ࡾ௡୩༗‫و‬, ࡾӜོٛ, தా௚थ, দ౻੒߂, ࡔؒ੣, ஑ా࣌ߒ (‫ޱ‬಄ൃද), ʮ௒఻ಋసҠ୺ηϯαʹΑΔ࣏ྍ༻୸ૉॏཻࢠΧϩϦϝτϦʯ, ୈ 80 ճԠ༻෺ཧֶձळ‫ֶق‬ज़ߨԋձ, ๺ւಓେֶ, ࡳຈ, 2019 ೥ 9 ݄ 18–21 ೔.
େ໺խ࢙, εϛεϥΠΞϯ, ࡾӜོٛ, தా௚थ, ࡾ௡୩༗‫و‬, ߴ‫ߒڮ‬೭, ஑ా࣌ߒ, ࡔؒ੣, দ౻੒߂ (‫ޱ‬಄ൃද), ʮ௒఻ಋసҠ୺ηϯαʹΑΔॏཻࢠϏʔϜਫ਼ີ‫ܭ‬ଌʯ, ୈ 80 ճԠ༻෺ཧֶձळ‫ֶق‬ज़ߨԋձ, ๺ւಓେֶ, ࡳຈ, 2019 ೥ 9 ݄ 18–21 ೔.
஑ా࣌ߒ, Ҿؒ༒Ֆ, ৿ޫਖ਼, Տଜढ़࠸, ۚӴࠃ (‫ޱ‬಄ൃද), ʮϑλ෇ΨϥεΩϟϐϥϦʔͰੜ੒͞Εͨ MeV ΠΦϯϚΠΫϩϏʔϜͷ
CR-39 ʹΑΔεϙοτߏ଄ධՁʯ, ୈ 62 ճ์ࣹઢԽֶ౼࿦ձ, ෱Ҫେֶෟଐࠃࡍ‫ॴڀݚֶ޻ྗࢠݪ‬, ರլ, 2019 ೥ 9 ݄ 23–25 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

ञҪխ࠸, ஑ా࣌ߒ, ࣲా३࢙, ઘխࢠ, ஛ຊ݈ਓ, ্ࡔॆ (‫ޱ‬಄ൃද), ʮα ઢ࣏ྍͷͨΊͷ He ΠΦϯϚΠΫϩϏʔϜ DNA রࣹ෼ੳͷ‫ڀݚૅج‬ʯ, ೔ຊ‫ֶྗࢠݪ‬ձ 2020 ೥य़ͷ೥ձ, ෱ౡେֶ, ෱ౡ, 2020 ೥ 3 ݄ 16–18 ೔.
ຊྛಁ, ஑ా࣌ߒ, ੴࢁത߃, ϐʔλʔ υʔωϯόϧ, ࠤ౻޿ւ, ্໺लथ (‫ޱ‬಄ൃද), ʮਔՊεΫʔϧ—‫֩ࢠݪ‬൓Ԡ࣮‫ݧ‬Λத৺ͱֶͨ͠෦ֶੜ޲͚ࠃࡍϓϩάϥϜʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
஑ా࣌ߒ, ञҪխ࠸, ஛ຊ݈ਓ, ࣲా३࢙, ઘխࢠ, ্ࡔॆ (‫ޱ‬಄ൃද), ʮΨϥεΩϟϐϥϦʔͰੜ੒͞ΕͨΠΦϯϚΠΫϩϏʔϜʹΑΔ RPE ࡉ๔ͷ DNA ଛই༠ൃ࣮‫ݧ‬ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
Ҿؒ༒Ֆ, ஑ా࣌ߒ, ඿ֶ֞, ۚӴࠃ (‫ޱ‬಄ൃද), ʮΨϥεΩϟϐϥϦʔޫֶ‫ʹܥ‬ΑΔΠΦϯϚΠΫϩϏʔϜͷরࣹ‫ͱ཭ڑ‬εϙοταΠζͷ૬ؔʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.

AwardsՏଜढ़࠸, JSRC Young Scientist Award for 16th International Congress of Radiation Research (ICRR2019), ೔ຊ์ࣹઢԽֶձ, 2019 ೥
7 ݄ 12 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Accelerator Applications Research Division
Beam Mutagenesis Group
1. Abstract
This group promotes biological applications of ion beams from RI Beam Factory (RIBF). Ion Beam Breeding Team studies
various biological eﬀects of fast heavy ions and develops new technology to breed plants and microbes by heavy-ion irradiations.
Plant Genome Evolution Research Team studies the eﬀect of chromosomal rearrangements on plant genomes and phenotypes.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Biological eﬀects of fast heavy ions
Molecular nature of DNA alterations induced by heavy-ion irradiation
Research and development of heavy-ion breeding
Identification of plant sex-determining genes using mutants and their evolutionary study

3. Summary of Research Activity
Summary of research activities of the two teams are given in the sections of each team.

MemberDirector
Tomoko ABE

List of Publications & Presentations
Publications and presentations for each research team are listed in subsections.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Accelerator Applications Research Division
Beam Mutagenesis GroupIon Beam Breeding Team
1. Abstract

Ion beam breeding team studies various biological eﬀects of fast heavy ions. It also develops new technique to breed plants andmicrobes by heavy-ion irradiations. Fast heavy ions can produce dense and localized ionizations in matters along their tracks, incontrast to photons (X rays and gamma rays) which produce randomly distributed isolated ionizations. These localized and dense
ionization can cause double-strand breaks of DNA which are not easily repaired and result in mutation more eﬀectively than singlestrand breaks. A unique feature of our experimental facility at the RIKEN Ring Cyclotron (RRC) is that we can irradiate living
tissues in atmosphere since the delivered heavy-ion beams have energies high enough to penetrate deep in matter. This team utilizes adedicated beam line (E5B) of the RRC to irradiate microbes, plants and animals with beams ranging from carbon to iron. Its researchsubjects cover study of ion-beam radiation mutagenesis, genome-wide analyses of mutation, and development of new plants andmicrobial varieties by heavy-ion irradiation. Thirty new varieties have already been brought to the market.

2. Major Research Subjects(1) Study on the biological eﬀects by heavy-ion irradiation(2) Study on the molecular nature of DNA alterations induced by heavy-ion irradiation(3) Innovative applications of heavy-ion beams

3. Summary of Research Activity

We study biological eﬀects of fast heavy ions from the RRC using 135 A MeV C, N, Ne ions, 95 A MeV Ar ions, 90 A MeV Fe
ions and from the IRC using 160 A MeV Ar ions. We also develop breeding technology of microbes and plants. Main subjects are:(1) Study on the biological eﬀects by heavy-ion irradiation
Heavy-ion beam deposits a concentrated amount of dose at just before stop with severely changing the linear energy transfer(LET). The peak of LET is achieved at the stopping point and known at the Bragg peak (BP). Adjusting the BP to target malignant
cells is well known to be eﬀective for cancer therapy. On the other hand, a uniform dose distribution is a key to the systematic study
for heavy-ion mutagenesis, thus to the improvement of the mutation eﬃciency. Plants and microbes therefore, are irradiated usingions with stable LET. We investigated the eﬀect of LET ranging from 23 to 640 keV/µm, on mutation induction using dry seeds ofthe model plants Arabidopsis thaliana and rice (Oryza sativa L.). The most eﬀective LET (LETmax) was 30 keV/µm in Arabidopsis
and rice dry seeds. LETmax irradiations showed the same mutation rate as that by chemical mutagens, which typically cause highmutation rate. The LETmax of imbibed rice seeds and dry wheat (Triticum monococcum) seeds were shown to be 50–63 keV/µm and50 keV/µm, respectively. In the case of microbe, filamentous fungus (Neurospora crassa), the Ar ions at 290 keV/µm demonstrated
higher mutagenic activity than the Fe-ions at 640 keV/µm. Thus, the LET is an important factor to be considered in heavy-ion
mutagenesis.
(2) Study on the molecular nature of DNA alterations induced by heavy-ion irradiation
We analyzed the DNA alterations corresponding to morphological mutants in Arabidopsis and rice. In the mutants from C- andAr-ions irradiations, the majority of the induced mutations were deletions. The proportion of large deletions (>100 bp) increased
with increasing LET. We concluded that the size of deletions generated by heavy-ion beam irradiation increased with increasing LET.
Whole-genome analysis by high-through put sequencing is a powerful tool used to characterize the nature of induced mutations.
We also developed a new pipeline named the Automated Mutation Analysis Pipeline (AMAP), for the rapid detection of wholegenome mutations in Arabidopsis. We comprehensively characterized the mutation eﬀects of ion beams of C (30 keV/µm) and Ar(290 keV/µm) by whole-genome mutational analysis on eight morphological mutants with AMAP. C ions at a dose of 400 Gy mainly
induced single-nucleotide variants (SNVs) and small insertions and deletions (InDels) at a rate of 57 sites per mutant genome. LETmax
irradiation is eﬀective for breeding because of its very high mutation frequency. Most mutations are SNV and small deletions which
are capable of disrupting a single gene. Thus, irradiation can eﬃciently generate knockout mutants of a target gene and can be applied
to reverse genetics. On the other hand, irradiation with Ar ions at a dose of 50 Gy showed a mutation spectrum diﬀerent from that at
LETmax. The proportion of SNVs and small InDels was low at a rate of 28 sites per mutant genome, while that of large deletions andchromosomal rearrangements was high (10 sites per mutant genome). As such, higher LET irradiation is promising as a new mutagen
suitable for the functional analysis of tandem duplicated genes.
(3) Innovative application of heavy-ion beams
In 1999, we formed a consortium for ion-beam breeding consisting of 24 groups. In 2019, the consortium grew to 184 groups
from Japan and 20 from overseas. Previously, the ion-beam breeding procedures were carried out using mainly flowers and ornamental
plants. We have recently put a new non-pungent and tearless onion, ‘Smile ball,’ on the market along with ‘Kiku Meigetsu,’ an edible
late flowering chrysanthemum. In addition, a new project was launched to expand the cultivation area of this variety of chrysanthemum
in Yamagata prefecture. Beneficial variants have been cultivated for various plant species, such as high yield sea weeds, lipidshyperaccumulating unicellular alga, large marine plankton and lettuce with a low browning property as a cut vegetable. We collaborate- 336 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

with Miyagi prefectural government and Tohoku University to breed salt-resistant lines in the more delicious commercial rice varieties,‘Hitomebore’ and ‘Manamusume.’ Imbibed seeds were irradiated with the LETmax (C-ions) on 16 April, 2011. We have isolated
a candidate line of salt-resistant mutant from 719 M2 progenies grown in the saline paddy field in 2012. This line grew well after
transplantation and had high yield in common paddy field as well. By broadening the target of heavy-ion breeding extending fromflowers to crops such as grains, the technology will contribute to solving the global problems of food shortage and environmental
destruction.

Members
Team Leader
Tomoko ABE
Research/Technical Scientists
Tokihiro IKEDA (Senior Research Scientist)
Masako IZUMI (Senior Research Scientist)
Teruyo TSUKADA (Senior Research Scientist)

Kazuhide TSUNEIZUMI (Senior Research Scientist)
Ryouhei MORITA (Technical Scientist)

Research & Development Scientist
Hiroyuki ICHIDA
Technical Staﬀ I
Yoriko HAYASHI

Yuki SHIRAKAWA

Technical Staﬀ II
Sumie OHBU

Mieko YAMADASpecial Temporary Technical Scientists
Hiroshi ABE

Katsunori ICHINOSE

Research Consultant
Masahiro MII (Chiba Univ.)
Visiting Scientists
Ayumi DEGUCHI (Chiba Univ.)
Makoto FUJIWARA (Sophia Univ.)
Eitaro FUKATSU (Forestry and Forest Products Res. Inst.)
Tomonari HIRANO (Univ. of Miyazaki)
Akiko HOKURA (Tokyo Denki Univ.)
Yutaka MIYAZAWA (Yamagata Univ.)
Kazumitsu MIYOSHI (Chiba Univ.)
Toshikazu MORISHITA (Nat’l Agriculture and Food Res.
Org.)
Koji MURAI (Fukui Prefectural Univ.)

Kyosuke NIWA (Tokyo Univ. of Marine Sci. and Tech.)
Norihiro OHTSUBO (Kyoto Prefectural Univ.)
Tadashi SATO (Tohoku Univ.)
Yoichi SATO (Riken Food Co., Ltd.)
Kenichi SUZUKI (Suntory Flowers Co., Ltd.)
Hinako TAKEHISA (Nat’l Inst. of Agrobiological Sci.)
Masanori TOMITA (Central Res. Inst. of Electric Power Industry)
Masao WATANABE (Tohoku Univ.)
Takeshi YAMAKI (Riken Vitamin Co., Ltd.)

Visiting Technicians
Yukiko KANAZAWA (Nippon Beet Sugar Manufacturing Co.,Ltd.)
Miho MOGAMIYA (Riken Food Co., Ltd.)
Research Fellow
Hironari UCHIDA (Saitama Agricultural Tech. Res. Center)
Student Trainee
Yuta HARUNARI (Tokyo Denki Univ.)
Part-time Worker
Haruka WATANABE (Administrative Part-time Worker II)- 337 -

Daisuke SAITO (Riken Food Co., Ltd.)
Takuji YOSHIDA (Takii & Co., Ltd)

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Original papers]
T. Kashiwabara, K. Tanoi, N. Kitajima, A. Hokura, T. Abe, T. Nakanishi, and I. Nakai, “Comparative in vivo imaging of arsenic andphosphorus in Pteris vittata gametophyte by synchrotron µ-XRF and radioactive tracer techniques,” Chem. Lett. 48, 319–321 (2019).
Y. Hayashi, S. Ishii, T. Hirano, K. Ichinose, Y. Kazama, and T. Abe, “New ornamental cherry cultivars induced by heavy-ion beamirradiation,” Acta Hortic. 1235, 99–103 (2019).
Ѩ෦஌ࢠ, ࢢా༟೭, ৿ాཽฏ, େ໺๛, ௕୩७޺, ߴ৓‫ܒ‬Ұ, ാԼণൣ, ଜҪߞೋ, ʮϛϡʔλήϊϛΫεͱมҟ౷߹σʔλϕʔεͷߏஙʯ, JATAFF δϟʔφϧ 7, 19–23 (2019).
M. Krasovec, Y. Kazama, K. Ishii, T. Abe, and D. A. Filatov, “Immediate dosage compensation is triggered by the deletion of Y-linked
genes in Silene latifolia,” Current Biol. 29, 2214–2221 (2019).
H. Kawamoto, K. Yamanaka, A. Koizumi, K. Ishii, Y. Kazama, T. Abe, and S. Kawano, “An asexual flower of Silene latifolia andMicrobotryum lychnidis-dioicae promotes sex-organ development,” PLoS One 14, e0217329 (2019).
H. Ichida and T. Abe, “An improved and robust method to eﬃciently deplete repetitive elements from complex plant genomes,” Plant Sci.
280, 455–60 (2019).
H. Murata, S. Nakano, T. Yamanaka, T. Shimokawa, T. Abe, H. Ichida, Y. Hayashi, K. Tahara, and A. Ohta, “Conversion from mutualism to parasitism: a mutant of the ectomycorrhizal agaricomycete Tricholoma matsutake that induces stunting, wilting, and root
degeneration in seedlings of its symbiotic partner, Pinus densiflora, in vitro,” Botany 97, 463–474 (2019).
H. Ichida, R. Morita, Y. Shirakawa, Y. Hayashi, and T. Abe, “Targeted exome sequencing of unselected heavy-ion beam-irradiatedpopulations reveals less-biased mutation characteristics in the rice genome,” Plant J 98, 301–314 (2019).
R. Morita, H. Ichida, K. Ishii, Y. Hayashi, H. Abe, Y. Shirakawa, K. Ichinose, K. Tsuneizumi, T. Kazama, K. Toriyama, T. Sato, and
T. Abe, “LONG GRAIN 1: a novel gene that regulates grain length in rice,” Mol. Breed. 39, 135–142 (2019).
Y. Sawada, M. Sato, M. Okamoto, J. Masuda, S. Yamaki, M. Tamari, Y. Tanokashira, S. Kishimoto, A. Ohmiya, T. Abe, and M. Y. Hirai, “Metabolome-based discrimination of chrysanthemum cultivars for the eﬃcient generation of flower color variations in mutation
breeding,” Metabolomics 15, 118–129 (2019).

Presentations[International conferences/workshops]
H. Ichida (invited), R. Morita, Y. Shirakawa, Y. Hayashi, and T. Abe, “A less-biased approach to characterize carbon-ion beam-induced
mutations by whole exome sequencing of unselected M2 populations in rice,” Rice Functional Genomics Workshop in XXVII Plant &Animal Genome Conference, San Diego, USA, January 12–16, 2019.
K. Niwa (poster), T. Abe, and A. Kobiyama, “Possibility of polyploidy breeding using cryptic species in the marine crop Pyropia yezoensis(Bangiales, Rhodophyta),” 23rd International Seaweed Symposium, Jeju, Korea, April 28–May 3, 2019.
T. Abe (invited), H. Ichida, Y. Hayashi, Y. Shirakawa, K. Ishii, and R. Morita, “Ion-beam radiation mutagenesis and plant mutation
breeding,” 14th Conference of Society for the Advancement of the Breeding Research in Asia and Oceania, Gwangju, Korea, July 2–5,
2019.
H. Murata (oral), S. Nakano, T. Yamanaka, T. Shimokawa, T. Abe, H. Ichida, Y. Hayashi, K. Tahara, and A. Ohta, “Radiation mutagenesisof the ectomycorrhizal fungus Tricholoma matsutake,” The 10th International Workshop on Edible Mycorrhizal Mushrooms, Nagano,
Japan, October 23, 2019.
T. Hioki (oral), H. Kunitake, T. Abe, and T. Hirano, “Analysis of petal size regulatory mechanisms in flower mutant of Arabidopsis
thaliana,” The 14th JKTC Seminar, Qingdao, China, October 18–21, 2019.

[Domestic conferences/workshops]Ѩ෦஌ࢠ (ট଴ߨԋ), ྛґࢠ, ࢢా༟೭, ʮIon Beam Mutagenesis ͱΠΦϯϏʔϜ඼छվྑϓϥοτϑΥʔϜʯ, ୈ 1 ճ ॏɾΫϥελʔΠΦϯϏʔϜར༻ʹΑΔඍੜ෺༝དྷߴੜ࢈ੑΤωϧΪʔ ‫ڥ؀‬γϯϙδ΢Ϝ, ஜ೾େֶ, ͭ͘͹, 2019 ೥ 1 ݄ 29 ೔.
্ా७ฏ (‫ޱ‬಄ൃද), ෩ؒ༟հ, Ѩ෦஌ࢠ, ଜҪߞೋ, ʮҰཻ‫ܥ‬ίϜΪ DV92 ‫ܥ‬౷ʹ͓͚ΔՖ੒஗Ԇมҟମ late-heading 2ʙ5 (lh2ʙ5) ͷಉఆʯ, ೔ຊҭछֶձ ୈ 135 ճߨԋձ, ઍ༿େֶ, ઍ༿, 2019 ೥ 3 ݄ 16–17 ೔.
, ೔ຊҭछֶձ ୈ 135 ճߨԋࢢా༟೭ (‫ޱ‬಄ൃද), Ѩ෦஌ࢠ, ʮޮ཰తͳ൓෮഑ྻআ‫ٕڈ‬ज़ͷ։ൃͱίϜΪશήϊϜղੳ΁ͷԠ༻ʯձ, ઍ༿େֶ, ઍ༿, 019 ೥ 3 ݄ 16–17 ೔.
ೋӋ‫ګ‬հ (‫ޱ‬಄ൃද), Ѩ෦஌ࢠ, খᐻࢁಞࢤ, ʮεαϏϊϦͱӅณछͷަࡶ࣮‫ݧ‬ʯ, ೔ຊ૶ྨֶձୈ 43 ճେձ, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019
೥ 3 ݄ 17 ೔.
Ѩ෦஌ࢠ (ট଴ߨԋ), ʮΠΦϯϏʔϜҭछٕज़Ͱເͷ২෺Λ૑Δʯ
, ୈ 6 ճϛχγϯϙʮ‫ػ‬ೳੑόΠΦʯ(TIA ͔͚͸͠‫ڀݚ‬ʮ‫ػ‬ೳੑόΠΦʯάϧʔϓ), ౦‫ژ‬େֶ, ദ, 2019 ೥ 3 ݄ 18 ೔.
ଜాफ‫ޱ( ݠ‬಄ൃද), ౉઒༑ཬ‫ܙ‬, ྛґࢠ, Ѩ෦஌ࢠ, ᅳ෢‫ొٱ‬, ฏ໺ஐ໵, ʮॏΠΦϯϏʔϜরࣹ༤ੑ഑‫͕ࢠۮ‬ॏෳडਫ਼ͱᡢൃੜʹ‫͢΅ٴ‬Ө‫ڹ‬ʯ, Ԃֶܳձฏ੒ 31 ೥౓य़‫ق‬େձ, ໌࣏େֶ, ઒࡚, 2019 ೥ 3 ݄ 23–24 ೔.
ৗઘ࿨ल (‫ޱ‬಄ൃද), ࢁాඒ‫ࢠܙ‬, Ұ੉উ‫ل‬, ࢢా༟೭, ۚᜉ௝, ഡ‫ݪ‬ಞࢤ, ઒ా࣮‫ق‬, ยࢁ‫࢜و‬, 㟒ࢁҰ޹, ख௩৴߂, খүխ඙, Ѩ෦஌ࢠ, ʮॏΠΦϯϏʔϜরࣹʹΑΔγΦϛζπϘϫϜγେ‫ܕ‬มҟ‫ܥ‬౷ͷҭछʯ, ೔ຊ೶ܳԽֶձ 2019 ೥౓େձ, ౦‫ژ‬೶‫ۀ‬େֶ, ੈ
ా୩, 2019 ೥ 3 ݄ 26–27 ೔.
ଜాਔ (‫ޱ‬಄ൃද), ஥໺ᠳଠ, ࢁதߴ࢙, Լ઒஌ࢠ, Ѩ෦஌ࢠ, ࢢా༟೭, ྛґࢠ, ా‫߃ݪ‬, ଠా໌, ʮೋһഓཆ‫ڞͰܥ‬ੜύʔτφʔͷΞΧϚπ࣮ੜබΛ‫ރ‬Β͢Ϛπλέมҟମͷ࡞ग़ʯ, ೔ຊ೶ܳԽֶձ 2019 ೥౓େձ, ౦‫ژ‬೶‫ۀ‬େֶ, ੈా୩, 2019 ೥ 3 ݄ 26–27 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Ѩ෦஌ࢠ (‫ޱ‬಄ൃද), ੴҪެଠ࿠, ෩ؒ༟հ, ฏ໺ஐ໵, ʮॏΠΦϯϏʔϜরࣹʹΑΓ༠ൃͨ͠γϩΠψφζφมҟͷಛ௃ʯ, ‫ૅج‬෺ཧֶ‫ڀݚॴڀݚ‬ձʮ์ࣹઢͷੜମӨ‫ڹ‬ղ໌΁ͷ෼໺ԣஅʹΑΔ௅ઓʯ, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019 ೥ 5 ݄ 23–25 ೔.
ੴҪެଠ࿠ (‫ޱ‬಄ൃද), ࢢా༟೭, Ѩ෦஌ࢠ, ʮΠωͷ඼छಛҟతߴਫ਼౓ϦϑΝϨϯε഑ྻ࡞੡ख๏ͷ։ൃʯ, ೔ຊҭछֶձୈ 136
ճߨԋձ, ۙ‫ـ‬େֶ, ಸྑ, 2019 ೥ 9 ݄ 6–7 ೔.
‫ٱ‬ଜຑࢠ (‫ޱ‬಄ൃද), ॾԬ३࢘, Ѩ෦஌ࢠ, ྛґࢠ, ฏ໺ஐ໵, ʮॏΠΦϯϏʔϜরࣹʹΑΔՆळখΪΫ඼छʮ௕࡚ SWC1ʯͷҭ੒ʯ,೔ຊҭछֶձୈ 136 ճߨԋձ, ۙ‫ـ‬େֶ, ಸྑ, 2019 ೥ 9 ݄ 6–7 ೔.
ઘխࢠ (ϙελʔൃද), Ѩ෦஌ࢠ, ʮॏཻࢠઢʹΑΓ༠ൃ͞ΕΔ DNA ೋຊ࠯੾அͷम෮‫ߏػ‬ͷղੳʯ, ୈ 42 ճ೔ຊ෼ࢠੜ෺ֶձେ
ձ, ෱Ԭࠃࡍձٞ৔ ϚϦϯϝοη෱Ԭ, ෱Ԭ, 2019 ೥ 12 ݄ 3–6 ೔.
Ѩ෦஌ࢠʢট଴ߨԋ), ʮΠΦϯҭछͷ‫ݱ‬ঢ়ͱͦΕͧΕͷࢪઃͷಛ௃ʯ, ෱ҪΠΦϯϏʔϜҭछ‫ڀݚ‬ձ, ए‫ڱ‬࿷ΤωϧΪʔ‫ڀݚ‬ηϯλʔ, ರլ, 2019 ೥ 12 ݄ 13 ೔.
౻ా༔ੜ (‫ޱ‬಄ൃද), ࢢా༟೭, ෩ؒஐ඙, Ѩ෦஌ࢠ, ௗࢁ‫࠸ێ‬, ʮindica ඼छ Lebed ʹ୆த 65 ߸Λ໭͠ަࡶͯ͠ಘΒΕͨ༤ੑෆູ
ੑͷղੳʯ, ࠃཱҨ఻ֶ‫ ॴڀݚ‬Πωଐۙԑछ‫ڀݚ‬ձʮOryza ଐήϊϜ৘ใΛ‫ͨ͠༻׆‬Ҩ఻తଟ༷ੑ‫ڀݚ‬ͷਪਐʯ, ࠃཱҨ఻‫ॴڀݚ‬,ࡾౡ, 2019 ೥ 12 ݄ 12–13 ೔.

Press releases
ࢢా༟೭, Ѩ෦஌ࢠ, ʮޮ཰తͳ൓෮഑ྻআ‫ٕڈ‬ज़ͷ։ൃͱίϜΪશήϊϜղੳ΁ͷԠ༻ʯ, ೔ຊҭछֶձ 2019 ೥य़‫ق‬େձʢ135ճʣઍ༿େֶ ‫ൃऀه‬ද, 2019 ೥ 3 ݄ 7 ೔.
੩Ԭ‫ݝ‬, ʮ৽඼छʮS1200ʯ΁ͷ‫ظ‬଴ʯ, ੩Ԭ‫ݝ‬೶ྛٕज़‫ॴڀݚ‬, ‫ॴڀݚ‬χϡʔε 58, 2019 ೥ 8 ݄.
‫ٱ‬ଜຑࢠ, ॾԬ३࢘, Ѩ෦஌ࢠ, ྛґࢠ, ฏ໺ஐ໵, ʮॏΠΦϯϏʔϜ঎ࣾʹΑΔՆळখΪΫ඼छʮ௕࡚ SWC1ʯͷҭ੒ʯ, ೔ຊҭछ
ֶձ 2019 ೥ळ‫ق‬େձʢ136 ճʣ, ۙ‫ـ‬େֶ ‫ൃऀه‬ද, 2019 ೥ 9 ݄ 3 ೔.

PatentsѨ෦஌ࢠ, ৿ాཽฏ, ྛґࢠ, ࢢా༟೭, ҆෦߂, ࠤ౻խࢤ, ʮछࢠͷαΠζ͕૿େͨ͠২෺ͷ੡଄ํ๏ʯ, ಛ‫ڐ‬ग़‫ئ‬൪߸ 2019-000749,
ग़‫ئ‬೔ 2019 ೥ 1 ݄ 7 ೔.
Ѩ෦஌ࢠ, ৗઘ࿨ल, ࢢా༟೭, ഡ‫ݪ‬ಞࢤ, ΩϜɾώδϯ, ࡕ૔ྑ޹, ੁ޲ࢤ࿠, খүխ඙, ख௩৴߂, ઒ా࣮‫ق‬, খྛ‫ܟ‬య, ʮϫϜγͷมҟ‫ܥ‬౷ͷ࡞ग़ํ๏, ϫϜγͷมҟ‫ܥ‬౷, ͓ΑͼॏΠΦϯϏʔϜͷ൑ఆํ๏ʯಛ‫ڐ‬ग़‫ئ‬൪߸ 2019-015899, ग़‫ئ‬೔ 2019 ೥ 1 ݄ 31 ೔.
‫ٱ‬ଜຑࢠ, ॾԬ३࢘, Ѩ෦஌ࢠ, ྛґࢠ, ฏ໺ஐ໵, ʮΩΫ඼छ’ ௕࡚ SWC1’ʯ, ඼छొ࿥ग़‫ئ‬൪߸ 33790, ग़‫ئ‬೔ 2019 ೥ 3 ݄ 18 ೔.
མ߹੒ޫ, Ѩ෦஌ࢠ, ྛґࢠ, ʮϋΠϏεΧε඼छ’ ϚβʔΦϨϯδ’ʯ, ඼छొ࿥ग़‫ئ‬൪߸ 33885, ग़‫ئ‬೔ 2019 ೥ 4 ݄ 22 ೔.

Outreach activitiesѨ෦஌ࢠ, ࢢా༟೭, ࢁాඒ‫ࢠܙ‬, ʮॏΠΦϯϏʔϜʹ཮্ཆ৩, ʮϫΧϝͷֵ৽ʯਐΉʯ೔ຊͷԑਂ͖ւ૶, ͦͷྺ࢙ͱ‫ࡏݱ‬ʢ‫ޙ‬ฤʣ, https://jbpress.ismedia.jp/articles/-/55473, ࣫‫࣍ݪ‬࿠ʢ‫ऀه‬ʣ, ‫ݱ‬୅Ϗδωε, ৯ͷ‫ॴڀݚ‬, 2019 ೥ 2 ݄ 15 ೔.
https://www.foods-ch.com/shokuhin/1556092438588/, ϑʔζνϟωϧ, 2019 ೥ 4 ݄ 25 ೔ʢసࡌʣ
We established the “Asagao (Morning glory) Club” to deepen the understanding of our technology of mutation breeding. The club
distributes the morning glory seeds irradiated with C-ion on request, and collects and compiles the observation reports of their growth.
Some reports have been featured in the booklet issued by the club every two years.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Accelerator Applications Research Division
Beam Mutagenesis Group
Plant Genome Evolution Research Team
1. Abstract
Established in May 2018, the plant genome evolution research team studies the eﬀect of heavy-ion induced mutations on plant
phenotypes. Chromosome rearrangements including translocation, inversion, and deletion are thought to play an important role inevolution and have a great potential to provide large phenotypic changes. However, this potential has not been fully investigated because of the lack of an eﬀective method to induce rearrangements. We recently found that chromosomal rearrangements are frequently
induced after heavy-ion irradiations with high valence numbers such as Fe ions or Ar ions. This frequency is 30 times higher thanthat of the previous techniques and allows characterization of the eﬀect of chromosomal rearrangements. We develop amd optimize
molecular and bioinfoematics techniquws based on the resent progress on genome sequencing technology, to eﬃciently identify andanalyse genomic mutations from model and non-model plant species. we also utilise this heavy-ion’s unique capability for plant
breeding and evolution studies.

2. Major Research Subjects(1) Study on the eﬀect of chromosomal rearrangements on plant genomes and phenotypes(2) Identification of the plant sex-determining genes and their evolutionary study

3. Summary of Research Activity(1) Study on the eﬀect of chromosomal rearrangements on plant genomes and phenotypes
In order to investigate the eﬀect of chromosome rearrangements on plant phenotypes, we analysed the Arabidopsis mutant Ar55as1, which were originally induced by Ar-beam irradiation at a dose of 50 Gy with an LET of 290 keV/µm. This mutant has no
homozygous mutation in any genes but has chromosomal rearrangements in the genome. This mutant shows a clear morphologicalmutant phenotype in which the petiole is shorter than wild-type plants. As a result of the investigation of the trait of each individual
and the presence or absence of chromosome rearrangements in the M3 generation of the mutant, we found that the inversion ofchromosome 2 is responsible for the phenotype. In addition, this inversion was found to be a dominant mutation. From this finding,we showed that a chromosome rearrangement can dominantly aﬀect the plant phenotype. We are currently investigating the eﬀect of
this inversion on gene expression.
We also attempted to induce a chromosome rearrangement at a target position by using genome editing technology, because thistechnique will be necessary when the functional analysis of chromosomal rearrangements will be performed in the future. There has
been no report in which a large chromosomal rearrangement was induced in A. thaliana by the genome editing. However, we expectedthat if it is a proven chromosomal region where chromosome rearrangement has occurred by heavy-ion irradiation, it can be induced
even when using genome editing. As a result, 760-kb inversion or deletion was successfully induced by genome editing.
(2) Identification of the plant sex-determining genes and their evolutionary study
A dioecious plant, Silene latifolia, has heteromorphic sex chromosomes (X and Y). We previously identified sex changing mutantsof S. latifolia by heavy-ion mutagenesis. The sex-changing mutants include hermaphroditic mutants and asexual mutants. The former
has both stamens and gynoecium, while the latter have no reproductive organs. By whole-genome analysis and RNA seq analysis, wehave idetified a gene that is deleted in all 14 of the 14 hermaphroditic mutants. This gene could be a candidate of sex determinant genewith gynoecium suppressing function.

Members
Team Leader
Tomoko ABEContract Researcher
Kotaro ISHII
Visiting Scientists
Ali FERJANI (Tokyo Gakugei Univ.)

Yusuke KAZAMA (Fukui Prefectural Univ.)

Student Trainees
Andi M. OKASA (Tohoku Univ.)
Part-time Worker
Yukako ABE (Part-time Worker)- 340 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Original papers]
N. Fujita, Y. Kazama, N. Yamagishi, K. Watanabe, S. Ando, H. Tsuji, S. Kawano, N. Yoshikawa, and K. Komatsu, “Development of the
VIGS system in the dioecious plant Silene latifolia,” Int. J. Mol. Sci. 20, 1031 (2019).
M. Krasovec, Y. Kazama, K. Ishii, T. Abe, and D. A. Filatov, “Immediate dosage compensation is triggered by the deletion of Y-linked
genes in Silene latifolia,” Current Biol. 29, 2214–2221 (2019).
R. Morita, H. Ichida, K. Ishii, Y. Hayashi, H. Abe, Y. Shirakawa, K. Ichinose, K. Tsuneizumi, T. Kazama, K. Toriyama, T. Sato, and
T. Abe, “LONG GRAIN 1: a novel gene that regulates grain length in rice,” Mol. Breed. 39, 135 (2019).
H. Kawamoto, K. Yamanaka, A. Koizumi, K. Ishii, Y. Kazama, T. Abe, and S. Kawano, “An asexual flower of Silene latifolia andMicrobotryum lychnidis-dioicae promotes sex-organ development,” PLoS One 14, e0217329 (2019).

Presentations[International conferences/workshops]
K. Ishii, Y. Kazama, T. Hirano, T. Takeshita, S. Kawano, and T. Abe (poster), “Development of a pipeline for whole-genome mutational
analysis and its application on heavy-ion mutagenesis,” Rice Functional Genomics Workshop in XXVII Plant & Animal Genome
Conference, San Diego, USA, January 12–16, 2019.
T. Abe (invited), H. Ichida, Y. Hayashi, Y. Shirakawa, K. Ishii, and R. Morita, “Ion-beam radiation mutagenesis and plant mutation
breeding,” 14th Conference of Society for the Advancement of the Breeding Research in Asia and Oceania, Gwangju, Korea, July 2–5,
2019.

[Domestic conferences/workshops]෩ؒ༟հ (ট଴ߨԋ), “Study of plant sex chromosome by using heavy-ion induced mutants,” ୈ 1 ճ ॏɾΫϥελʔΠΦϯϏʔϜར༻ʹΑΔඍੜ෺༝དྷߴੜ࢈ੑΤωϧΪʔ, ‫ڥ؀‬γϯϙδ΢Ϝ, ஜ೾େֶ, ͭ͘͹, 2019 ೥ 1 ݄ 29 ೔.
্ా७ฏ, ෩ؒ༟հ, Ѩ෦஌ࢠ, ଜҪߞೋ (‫ޱ‬಄ൃද), ʮҰཻ‫ܥ‬ίϜΪ DV92 ‫ܥ‬౷ʹ͓͚ΔՖ੒஗Ԇมҟମ late-heading 2ʙ5 (l h2ʙ5) ͷಉఆʯ, ೔ຊҭछֶձ ୈ 135 ճߨԋձ, ઍ༿େֶ, ઍ༿ࢢ, 2019 ೥ 3 ݄ 16–17 ೔.
Ѩ෦஌ࢠ, ੴҪެଠ࿠, ෩ؒ༟հ, ฏ໺ஐ໵ (‫ޱ‬಄ൃද), ʮॏΠΦϯϏʔϜরࣹʹΑΓ༠ൃͨ͠γϩΠψφζφมҟͷಛ௃ʯ, ‫ૅج‬෺ཧֶ‫ڀݚॴڀݚ‬ձʮ์ࣹઢͷੜମӨ‫ڹ‬ղ໌΁ͷ෼໺ԣஅʹΑΔ௅ઓʯ, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019 ೥ 5 ݄ 23–25 ೔.
ੴҪެଠ࿠, ࢢా༟೭, Ѩ෦஌ࢠ (ϙελʔൃද), ʮΠωͷ඼छಛҟతߴਫ਼౓ϦϑΝϨϯε഑ྻ࡞੡ख๏ͷ։ൃʯ, ೔ຊҭछֶձୈ
136 ճߨԋձ, ۙ‫ـ‬େֶ, ಸྑ, 2019 ೥ 9 ݄ 6–7 ೔.
෩ؒ༟հ, M. Krasovec, ੴҪެଠ࿠, Ѩ෦஌ࢠ, D. A. Filatov (‫ޱ‬಄ൃද), ʮࣁ༤ҟ‫ג‬২෺ώϩϋϊϚϯςϚͰൃ‫ͨ͠ݟ‬ੑછ৭ମͷଈ࣌Ҩ఻ࢠྔิਖ਼ʯ, ೔ຊҨ఻ֶձ 91 ճେձ, ෱Ҫେֶ, ෱Ҫ, 2019 ೥ 9 ݄ 11–14 ೔.
‫ڮ‬ຊՂ੅, ੢ӜѪࢠ, ্ా७ฏ, ෩ؒ༟հ, ࢢా༟೭, Ѩ෦஌ࢠ, ଜҪߞೋ (ϙελʔൃද), ʮॏΠΦϯϏʔϜʹΑͬͯ࡞ग़͞Εͨ௒‫ૣۃ‬ੜίϜΪมҟମ extra early-flowering 4 ʹ͓͚Δ‫ݪ‬ҼҨ఻ࢠͷಉఆʯ, ೔ຊҨ఻ֶձ 91 ճେձ, ෱Ҫେֶ, ෱Ҫ, 2019 ೥ 9 ݄
11–14 ೔.
ञҪਹਓ, ฏాઍᜢ, ෩ؒ༟հ, Ѩ෦஌ࢠ, ࡾଜప࿠, ਂ৓ӳ߂, ੴ࡚ެ߁ (ϙελʔൃද), ʮॏΠΦϯϏʔϜরࣹ๔ࢠΛ༻͍ͨθχΰέ഑‫ۮ‬ମ‫ܗ‬ଶ‫ܗ‬੒มҟମͷεΫϦʔχϯάͱղੳʯ, ೔ຊ২෺ֶձ 83 ճେձ, ౦๺େֶ, ઋ୆ࢢ, 2019 ೥ 9 ݄ 15–17 ೔.
౉ᬑང, େ෦੅ߐ, Ѩ෦஌ࢠ, ෩ؒ༟հ (ϙελʔൃද), ʮήϊϜฤूʹΑΔγϩΠψφζφ΁ͷછ৭ମ࠶ฤ੒ͷಋೖʯ, ೔ຊ২෺ֶ
ձ 83 ճେձ, ౦๺େֶ, ઋ୆, 2019 ೥ 9 ݄ 15–17 ೔.
෩ؒ༟հ (‫ޱ‬಄ൃද), ʮછ৭ମ࠶ฤ੒: ͦͷ༠ൃͱද‫ʹܕݱ‬༩͑ΔӨ‫ڹ‬ʯ, ୈ 12 ճ๺཮߹ಉόΠΦγϯϙδ΢Ϝ, ਗ਼෩૳, ͋ΘΒ,2019 ೥ 10 ݄ 25–26 ೔.
্ా७ฏ, ෩ؒ༟հ, Ѩ෦஌ࢠ, ࢢా༟೭, ଜҪߞೋ (ϙελʔൃද), ʮҰཻ‫ܥ‬ίϜΪ (Triticum monococcum) KU104-2 ͓Αͼ DV92‫ܥ‬౷͔Β࡞ग़ͨ͠Ֆ੒஗Ԇมҟମ late-heading1, 2 (l h1, 2) ͷղੳʯ, ୈ 14 ճϜΪྨ‫ڀݚ‬ձ, ௗऔେֶ‫ס‬૩஍‫ڀݚ‬ηϯλʔ, ௗऔ,2019 ೥ 11 ݄ 2–3 ೔.
‫ڮ‬ຊՂ੅, ੢ӜѪࢠ, ্ా७ฏ, ෩ؒ༟հ, Ѩ෦஌ࢠ, ࢢా༟೭, ଜҪߞೋ (ϙελʔൃද), ʮॏΠΦϯϏʔϜরࣹʹΑͬͯ࡞ग़͞Εͨ௒‫ૣۃ‬ੜίϜΪมҟମ extra early-flowering 4 ʹ͓͚Δ‫ݪ‬ҼҨ఻ࢠͷಉఆʯ, ୈ 14 ճϜΪྨ‫ڀݚ‬ձ, ௗऔ, ௗऔେֶ‫ס‬૩஍‫ڀݚ‬ηϯλʔ, 2019 ೥ 11 ݄ 2–3 ೔.
ߴ৓‫ܒ‬Ұ, ੴҪެଠ࿠, ാԼণൣ, Ѩ෦஌ࢠ (ϙελʔൃද), ʮATM/ATR ‫ػ‬ೳܽଛγϩΠψφζφࠜ୺ʹ͓͚Δ X ઢরࣹ‫ޙ‬ͷ
γ-H2AX ͷۭ࣌ؒؒ෼෍ʯ, ೔ຊ์ࣹઢӨ‫ֶڹ‬ձୈ 62 ճେձ, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019 ೥ 11 ݄ 14–16 ೔.
෩ؒ༞հʢট଴ߨԋ), ʮ෱Ҫ‫ཱݝ‬େֶʹ͓͚ΔΠΦϯҭछͷల๬—Ԃܳ২෺ͷછ৭ମ࠶ฤ‫ڀݚ‬ʯ, ෱ҪΠΦϯϏʔϜҭछ‫ڀݚ‬ձ, ए‫ڱ‬࿷ΤωϧΪʔ‫ڀݚ‬ηϯλʔ, ರլ, 2019 ೥ 12 ݄ 13 ೔.

- 341 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Accelerator Applications Research Division
RI Application Research Group
1. Abstract
RI Application Research Group promotes industrial applications of radioisotopes (RI) and ion beams at RIKEN RI Beam Factory(RIBF). Nuclear Chemistry Research Team develops production technologies of useful RIs for application studies in nuclear andradiochemistry. The team also develops technologies of mass spectrometry for trace-element and isotope analyses and apply themto the research fields such as cosmochemistry, environmental science, archaeology, and so on. Industrial Application Research Team
promotes industrial applications of the accelerator facility and its related technologies.

2. Major Research Subjects(1) Research and development of RI production technologies at RIBF
(2) RI application researches(3) Development of trace element analyses using accelerator techniques and its application to geoscience and archaeologicalresearch fields(4) Development of chemical materials for ECR ion sources of the RIBF accelerators(5) Development of technologies on industrial utilization and novel industrial applications of RIBF
(6) Support of industrial utilization of the heavy-ion beams at RIBF
(7) Support of some materials science experiments(8) Fee-based distribution of RIs produced at RIBF

3. Summary of Research Activity
See the subsections of Nuclear Chemistry Research Team and Industrial Application Research Team.

Members
Director
Hiromitsu HABATeam Leaders
Hiromitsu HABA

Atsushi YOSHIDA

List of Publications & Presentations
See the subsections of Nuclear Chemistry Research Team and Industrial Application Research Team- 342 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Accelerator Applications Research Division
RI Application Research Group
Nuclear Chemistry Research Team
1. Abstract

The Nuclear Chemistry Research Team develops production technologies of unique radioisotopes (RIs) at RIKEN RI Beam
Factory (RIBF) and applies them in the research fields of physics, chemistry, biology, engineering, medicine, pharmaceutical andenvironmental sciences. The purified RIs such as 65 Zn, 67 Cu, 85 Sr, 88 Y, and 109 Cd are delivered to universities and institutes throughJapan Radioisotope Association. We also develop new technologies of mass spectrometry for the trace-element analyses using accelerator technology and apply them to the research fields such as cosmochemistry, environmental science, archaeology, and so on. We
perform various isotopic analyses on the elements such as S, Pd, and Pb using ICP-MS, TIMS, and IRMS. We also develop chemicalmaterials for ECR ion sources of the heavy-ion accelerators at RIBF.

2. Major Research Subjects(1) Research and development of RI production technologies at RIBF
(2) RI application researches(3) Development of trace element analyses using accelerator techniques and its application to geoscience and archaeologicalresearch fields(4) Development of chemical materials for ECR ion sources of the heavy-ion accelerators at RIBF

3. Summary of Research Activity(1) Research and development of RI production technologies at RIBF and RI application researches
Due to its high sensitivity, the radioactive tracer technique has been successfully applied for investigations of the behavior ofelements in the fields of chemistry, biology, engineering, medicine, pharmaceutical and environmental sciences. We have been developing production technologies of useful radiotracers at RIBF and conducting their application studies in collaboration with many
researchers in various fields. With 30-MeV proton, 24-MeV deuteron, and 50-MeV alpha beams from the AVF cyclotron, we presently
produce about 100 radiotracers from 7 Be to 211 At. Among them, 65 Zn, 67 Cu, 85 Sr, 88 Y, and 109 Cd are delivered to Japan Radioisotope
Association for fee-based distribution to the general public in Japan. Our RIs are also distributed to researchers under the Supply
Platform of Short-lived Radioisotopes for Fundamental Research, supported by MEXT KAKENHI. On the other hand, radionuclides
of a large number of elements are simultaneously produced from metallic targets such as nat Ti, nat Ag, nat Hf, 197 Au, and 232 Th irradiatedwith a 135-MeV nucl.−1 14 N beam from the RIKEN Ring Cyclotron. These multitracers are also supplied to universities and institutes
as collaborative researches.
In 2019, we developed production technologies of radioisotopes such as 24 Na, 42, 43 K, 44m Sc, 48 Cr, 111 Ag, 186 Re, 211 At, 224 Ra,
212
Pb, and 225 Ac which were strongly demanded but lack supply sources in Japan. We also investigated the excitation functions
for the nat V(p, x), nat Cr(p, x), nat La(p, x), 169 Tm(p, x), nat Ta(p, x), 45 Sc(d, x), nat Tl(d, x), nat Ca(α, x), nat Ni(α, x), nat Sb(α, x),nat Nd(α, x),nat
Gd(α, x), and nat Dy(α, x) reactions to quantitatively produce useful RIs. We used radiotracers of 42, 43 K, 44m Sc, 111 Ag, 186 Re, 211 At,
224
Ra, 212 Pb, and 225 Ac for application studies in chemistry, 24 Na, 42, 43 K, 44m Sc, 67 Cu, 186 Re, 211 At, and 225 Ac in nuclear medicine.
We also produced 65 Zn, 67 Cu, and 88 Y for our scientific researches on a regular schedule and supplied the surpluses through Japan
Radioisotope Association to the general public. In 2019, we accepted 2 orders of 65 Zn with a total activity of 6.7 MBq, 1 order of67
Cu with 5 MBq, and 2 orders of 88 Y with 2 MBq. We also distributed 44m Sc (2 MBq × 3), 88 Zr (1 MBq × 1 and 2 MBq × 1), 95 Nb(1 MBq × 2 and 2 MBq × 1), 124 Sb (2 MBq × 1), 141 Ce (9 kBq × 1 and 13 kBq × 1), 175 Hf (1 MBq × 1 and 2 MBq × 1), and 211 At(5 MBq × 4, 50 MBq × 6, 100 MBq × 11, and 120 MBq × 1) under the Supply Platform of Short-lived Radioisotopes for Fundamental
Research.
(2) Superheavy element chemistry
Chemical characterization of newly-discovered superheavy elements (SHEs, atomic numbers Z ≥ 104) is an extremely interesting and challenging subject in modern nuclear and radiochemistry. We are developing SHE production systems as well as rapid
single-atom chemistry apparatuses at RIBF. Using heavy-ion beams from RILAC and AVF, 261 Rf (Z = 104), 262 Db (Z = 105),265
Sg (Z = 106), and 266 Bh (Z = 107) are produced in the 248 Cm(18 O, 5n)261 Rf, 248 Cm(19 F, 5n)262 Db, 248 Cm(22 Ne, 5n)265 Sg, and248
Cm(23 Na, 5n)266 Bh reactions, respectively, and their chemical properties are investigated.
We installed a gas-jet transport system to the focal plane of the gas-filled recoil ion separator GARIS at RILAC. This system isa promising approach for exploring new frontiers in SHE chemistry: the background radiations from unwanted products are strongly
suppressed, the intense primary heavy-ion beam is absent in the gas-jet chamber, and hence the high gas-jet extraction yield is attained.
Furthermore, the beam-free condition makes it possible to investigate new chemical systems. To realize aqueous chemistry studies of
Sg and Bh, we have been developing a continuous and rapid solvent extraction apparatus which consists of a continuous dissolution
apparatus Membrane DeGasser (MDG), a Flow Solvent Extractor (FSE), and a liquid scintillation detector for α/SF-spectrometry.
On the other hand, we have a gas-jet coupled target system and a safety system for a radioactive 248 Cm target on the beam lineof AVF. In 2019, the distribution coeﬃcients of 261 Rf on the anion-exchange resin in the H2 SO4 system were measured with the
AutoMated Batch-type solid-liquid Extraction apparatus for Repetitive experiments of transactinides (AMBER) which was developedby the research group of Osaka University. The distribution coeﬃcients of 262 Db on the anion-exchange resin in the mixed HF/HNO3- 343 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

system were also measured with the Automated Rapid Chemistry Apparatus (ARCA) of Japan Atomic Energy Agency. We produced
radiotracers of 88 Zr, 95 Nb, 95m Tc, 175 Hf, 177, 179 Ta, and 183 Re at AVF and conducted model experiments for aqueous chemistry studies
on Rf, Db, and Bh. In 2019, we developed a cryogenic RF-carpet gas cell, which will be placed on the focal plane of GARIS andconnected to a gas chromatographic apparatus, for the future gas-phase chemistry of the short-lived SHEs (<3 s).
(3) Development of trace element analyses using accelerator techniques and its application to geoscience and archaeologicalresearch fields
We have been developing the ECR Ion Source Mass Spectrometer (ECRIS-MS) for trace element analyses. In 2019, we renovatedthe detection system of ECRIS-MS and evaluated its sensitivity and mass resolution power. We equipped a laser-ablation system with
an ion source and a pre-concentration system to achieve high-resolution analyses for noble gases such as Kr and Xe.
Using the conventional ICP-MS, TIMS, IRMS, and so on, we analyzed sediments such as a ferro-manganese nodule in the Pacific
Ocean to elucidate its growth history concerning the environmental changes in the ocean. We also studied Pb and S isotope ratios on
cinnabar and asphalt samples from ancient ruins in Japan to elucidate the distribution of goods in the archaic society and to reveal
the establishment of the Yamato dynasty in the period from Jomon to Tumulus. We established a sampling technique for pigment
without any damages on the artifacts or wall paintings, using a S-free adhesive tape. Then, we applied the technique to the analyses ofthe pigment from Roman ruins in Badalona, Spain. We also applied the technique to the analyses of the red-color substances on theartifacts such as Kyoden remains (Izumo-city, Shimane prefecture), Renpeijou-ato (Zentuji-city, Kagawa prefecture) and so on. We
also investigated the transmutation of the long-lived 107 Pd to the stable Pd isotopes by the deuteron-induced nuclear reaction.
(4) Development of chemical materials for ECR ion sources of the heavy-ion accelerators at RIBF
In 2019, we prepared metallic 238 U rods and 238 UO2 on a regular schedule for 238 U-ion accelerations with the 28-GHz ECR of
RILAC II.

Members
Team Leader
Hiromitsu HABA
Research/Technical Scientist
Kazuya TAKAHASHI (Senior Research Scientist)
Research & Development Scientist
Hiroo HASEBE
Contract Researcher
Yukiko KOMORISpecial Postdoctoral Researcher
Yudai SHIGEKAWA
Postdoctoral Researchers
Yang WANG

Takuya YOKOKITA

Technical Staﬀ I
Daiki MORI
Research Consultant
Hisaaki KUDO (Niigata Univ.)
Visiting Scientists
Masayuki AIKAWA (Hokkaido Univ.)
Kazuhiko AKIYAMA (Tokyo Metropolitan Univ.)
Ferenc DITRÓI (ATOMKI)
Osuke FUJIMOTO (Fujifilm Toyama Chemical Co., Ltd.)
Takahiro HIRAKI (Okayama Univ.)
Hayato IKEDA (Tohoku Univ.)
Noriko ISHIOKA (QST)
Masamichi KAJITA (Fujifilm Toyama Chemical Co., Ltd.)
Hiroshi KATO (Fujifilm Toyama Chemical Co., Ltd.)
Mayeen U. KHANDAKER (Sunway Univ.)
Hidetoshi KIKUNAGA (Tohoku Univ.)
Yoshikatsu KOGA (Nat’l Cancer Center)
Shoko KUBOTA (Fujifilm Toyama Chemical Co., Ltd.)
Takumi KUBOTA (Kyoto Univ.)

Susanta Kumar LAHIRI (Saha Inst. of Nucl. Phys.)
Takahiko MASUDA (Okayama Univ.)
Toshimitsu MOMOSE (Int’l Univ. of Health and Welfare)
Akio NAGANO (Fujifilm Toyama Chemical Co., Ltd.)Eri NAKAMURA (Fujifilm Toyama Chemical Co., Ltd.)
Kenichiro OGANE (Int’l Univ. of Health and Welfare)
Miki OHTSUKA (Waseda Univ.)
Kazuhiro OOE (Osaka Univ.)
Shinobu OSHIKIRI (Fujifilm Toyama Chemical Co., Ltd.)
Yasutaka SAITO (Fujifilm Toyama Chemical Co., Ltd.)Aya SAKAGUCHI (Univ. of Tsukuba)
Miho SATAKE (Fujifilm Toyama Chemical Co., Ltd.)
Yuki SATO (Fujifilm Toyama Chemical Co., Ltd.)
Kenji SHIMAZOE (Univ. of Tokyo)- 344 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Keisuke SUEKI (Univ. of Tsukuba)
Kentaro SUZUKI (Fujifilm Toyama Chemical Co., Ltd.)
Zoltán SZŰCS (ATOMKI) Sándor TAKÁCS (ATOMKI)
Hiroyuki TAKAHASHI (Univ. of Tokyo)
Miho TAKAHASHI (Tokyo Univ. of Marine Sci. and Tech.)
Miwako TAKAHASHI (Nat’l Inst. of Radiological Sci.)
Yuichi TAKAKU (Inst. for Environmental Sci.)
Hiroki TAKASHIMA (Nat’l Cancer Center)
Kazuo TANAKA (Tohoku Univ.)
Masayoshi TODA (Tokyo Univ. of Marine Sci. and Tech.)
Visiting Technicians
Hideyuki ARAI (Metal Tech. Co. Ltd.)
Hiroshi ARATA (Metal Tech. Co. Ltd.)
Hidehiro HASHIMOTO (Metal Tech. Co. Ltd.)
Yoshiyuki IIZUKA (ATOX Co., Ltd.)
Akimitsu KANDA (Japan Radioisotope Association)
Shota KIMURA (Japan Radioisotope Association)
Yukiyoshi KON (Osaka Univ.)
Takashi KURIHARA (Metal Tech. Co. Ltd.)

Atsushi TOYOSHIMA (Osaka Univ.)
Takashi UI (Fujifilm Toyama Chemical Co., Ltd.)
Naoyuki UKON (Fukushima Medical Univ.)
Ahmed R. USMAN (Umaru Musa Yar’adua Univ.)
Shigeki WATANABE (QST)
Chunli YANG (Inst. of Modern Phys.)
Akihiko YOKOYAMA (Kanazawa Univ.)
Zenko YOSHIDA (ATOX Co., Ltd.)
Koji YOSHIMURA (Okayama Univ.)

Takahiro MIKAMOTO (Japan Radioisotope Association)
Hiroki SHIBAHARA (ATOX Co., Ltd.)
Yuki TAKEMURA (ATOX Co., Ltd.)
Yasutaka TAKEUCHI (ATOX Co., Ltd.)
Shusaku TAZAWA (ATOX Co., Ltd.)
Yuichirou WAKITANI (Japan Radioisotope Association)
Mami YUKI (ATOX Co., Ltd.)

Student Trainees
Sadia ADACHI (Univ. of Tsukuba)
Kjeld A. A. G. BEEKS (Vienna Univ. of Tech.)
Desheng CHEN (Univ. of Chinese Academy of Sci.)
Wei Seng FOONG (Univ. of Tokyo)
Yuta HAYAKAWA (Kanazawa Univ.)
Sho HAYAMI (Osaka Univ.)
Xuan HOU (Univ. of Tokyo)
Ayuna KASHIHARA (Univ. of Tsukuba)
Mizuho KATO (Univ. of Tsukuba)
Cheonghun KIM (Univ. of Tokyo)
Mariko KOBAYASHI (Univ. of Tokyo)
Masaharu KURINO (Univ. of Tokyo)
Natsuki MATSUMURA (Kanazawa Univ.)
Ryoga MORITA (Kanazawa Univ.)
Tomohiro MURATA (Hokkaido Univ.)

Akihisa NAKAJIMA (Univ. of Tsukuba)
Kaito NISHIZUKA (Univ. of Tsukuba)
Koichi OKAI (Okayama Univ.)
Moemi SAITO (Hokkaido Univ.)
Michiya SAKAGUCHI (Hokkaido Univ.)
Kaori SHIRAI (Niigata Univ.)
Hayato SUZUKI (Ibaraki Univ.)
Yusuke SUZUKI (Univ. of Tsukuba)
Kakeru TERANISHI (Kanazawa Univ.)
Katsuyuki TOKOI (Ibaraki Univ.)
Katsuma TONAI (Osaka Univ.)
Mizuki UENOMACHI (Univ. of Tokyo)
Eisuke WATANABE (Osaka Univ.)
Yuki YASUDA (Osaka Univ.)
Zhihong ZHONG (Univ. of Tokyo)

Part-time Workers
Michiko KITAGAWA (Research Part-time Worker I)
Nozomi SATO (Research Part-time Worker I)

Sachiko USUDA (Research Part-time Worker I)
Minako OSANAI (Research Part-time Worker II)

List of Publications & Presentations
Publications[Original papers]
M. Aikawa, M. Saito, Y. Komori, H. Haba, S. Takács, F. Ditrói, and Z. Szűcs, “Activation cross sections of alpha-particle induced nuclear
reactions on natural palladium,” Nucl. Instrum. Methods Phys. Res. B, 449, 99–104 (2019).
E. Corniani, F. Ditrói, S. Takács, H. Haba, Y. Komori, M. Aikawa, M. Saito, and T. Murata, “Study of secondary implantation ofradioisotopes during alpha-particle irradiation,” J. Radioanal. Nucl. Chem. 320, 813–822 (2019).
M. Saito, M. Aikawa, T. Murata, N. Ukon, Y. Komori, H. Haba, and S. Takács, “Activation cross sections of alpha-induced reactions on
natural ytterbium upto 50 MeV,” Nucl. Instrum. Methods Phys. Res. B 453, 15–21 (2019).
M. Ebihara, Y. Oura, N. Shirai, Y. Nagakawa, N. Sakurai, H. Haba, H. Matsuzaki, H. Tsuruta, and Y. Moriguchi, “A new approachfor reconstructing the 131 I-spreading due to the 2011 Fukushima nuclear accident by means of measuring 129 I in airborne particulatematters,” J. Environ. Radio. 208-209, 106000-1–9 (2019).
T. Masuda, A. Yoshimi, A. Fujieda, H. Fujimoto, H. Haba, H. Hara, T. Hiraki, H. Kaino, Y. Kasamatsu, S. Kitao, K. Konashi, Y. Miyamoto,
K. Okai, S. Okubo, N. Sasao, M. Seto, T. Schumm, Y. Shigekawa, K. Suzuki, S. Stellmer, K. Tamasaku, S. Uetake, M. Watanabe,
T. Watanabe, Y. Yasuda, A. Yamaguchi, Y. Yoda, T. Yokokita, M. Yoshimura, and K. Yoshimura, “X-ray pumping of the 229 Th nuclear
clock isomer,” Nature 573, 238–242 (2019).
M. Saito, M. Aikawa, M. Sakaguchi, N. Ukon, Y. Komori, and H. Haba, “Production cross sections of ytterbium and thulium radioisotopes
in alpha-induced nuclear reactions on natural erbium,” Appl. Radiat. Isot. 154, 108874-1–6 (2019).

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Y. Shigekawa, Y. Kasamatsu, E. Watanabe, H. Ninomiya, S. Hayami, N. Kondo, Y. Yasuda, H. Haba, and A. Shinohara, “Observation ofinternal-conversion electrons emitted from 229m Th produced by beta decay of 229 Ac,” Phys. Rev. C 100, 044304-1–7 (2019).
A. Yamaguchi, H. Muramatsu, T. Hayashi, N. Yuasa, K. Nakamura, M. Takimoto, H. Haba, K. Konashi, M. Watanabe, H. Kikunaga,
K. Maehata, N. Y. Yamasaki, and K. Mitsuda, “Energy of the 229 Th nuclear clock isomer determined by absolute γ-ray energy diﬀerence,” Phys. Rev. Lett. 123, 222501-1–6 (2019).
T. Murata, M. Aikawa, M. Saito, H. Haba, Y. Komori, N. Ukon, S. Takács, and F. Ditrói, “Excitation function measurement for zirconium89 and niobium-90 production using alpha-induced reactions on yttrium-89,” Nucl. Instrum. Methods Phys. Res. B 458, 21–27 (2019).
S. Takács, M. Aikawa, M. Saito, T. Murata, N. Ukon, Y. Komori, and H. Haba, “Activation cross sections of alpha particle-induced
reactions on natural hafnium up to 50 MeV”, Nucl. Instrum. Methods Phys. Res. B 459, 50–58 (2019).
D. Ichinkhorloo, M. Aikawa, T. Zolbadral, Y. Komori, and H. Haba, “Activation cross sections of dysprosium-157, 159 and terbium-160
radioisotopes from the deuteron-induced reactions on terbium-159 up to 24 MeV,” Nucl. Instrum. Methods Phys. Res. B 461, 102–104(2019).
T. Minami, K. Hatanaka, Y. Motizuki, Y. Nakai, and K. Takahashi, “A method of collecting trace amounts of vermilion from artifacts forsource estimation by sulfur isotope (δ34 S) analysis: Use of sulfur-free adhesive tape to minimize damage to the artifact body during
sampling,” J. Archaeolog. Sci. Rep. 28, 102027-1–5 (2019).
A. R. Usman, M. U. Khandaker, H. Haba, N. Otuka, and M. Murakami, “Production cross sections of thulium radioisotopes for alphaparticle induced reactions on holmium,” Nucl. Instrum. Methods Phys. Res. B 469, 42–48 (2020).
M. Okamura, E. Beebe, S. Ikeda, T. Kanesue, D. Raparia, T. Karino, and H. Haba, “96 Zr beam production for isobar experiment inrelativistic heavy ion collider,” Rev. Sci. Instrum. 91, 013319-1–5 (2020).
T. Tanaka, K. Morita, K. Morimoto, D. Kaji, H. Haba, R. A. Boll, N. T. Brewer, S. Van Cleve, D. J. Dean, S. Ishizawa, Y. Ito, Y. Komori,K. Nishio, T. Niwase, B. C. Rasco, J. B. Roberto, K. P. Rykaczewski, H. Sakai, D. W. Stracener, and K. Hagino, “Fusion dynamics for
hot fusion reactions to synthesize superheavy nuclei revealed in quasielastic barrier distributions,” Phys. Rev. Lett. 124, 052502-1–96(2020).
M. U. Khandaker, H. Haba, Y. Komori, and N. Otuka, “Excitation functions of deuteron-induced nuclear reactions on erbium in the energy
range of 4–24 MeV,” Nucl. Instrum. Methods Phys. Res. B 470, 1–9 (2019).
Y. Wang, Y. Wittwer, J. Zhang, J. Yang, H. Haba, Y. Komori, T. Yokokita, S. Cao, F. Fan, R. Eichler, A. Türler, and Z. Qin, “Massspectrometric speciation of metal-carbonyls in the gas phase,” PSI Annual Report 2018, Laboratory of Radiochemistry, 13–14 (2019).
M. Sakaguchi, M. Aikawa, M. Saito, N. Ukon, Y. Komori, and H. Haba, “Production cross sections of 89 Zr by deuteron-induced reactions
on 89 Y,” JAEA-Conf 2019-001, 185–188 (2019).
T. Fukuchi, H. Haba, and H. Kikunaga, “Phantom production for a multiple-isotope β-ray imaging system,” ELPH Annual Report, Tohoku
University 2018, 105–106 (2019).
M. Saito, M. Aikawa, T. Murata, Y. Komori, H. Haba, S. Takács, F. Ditrói, and Z. Szűcs, “Production cross sections of 169 Yb by the
proton-induced reaction on 169 Tm,” Nucl. Instrum. Methods Phys. Res. B 471, 13–16 (2020).
Y. Kasamatsu, N. Kondo, K. Nakamura, Y. Kuboki, H. Ninomiya, Y. Shigekawa, E. Watanabe, Y. Yasuda, K. Toyomura, M. Nagase,
T. Yokokita, Y. Komori, H. Haba, T. Yoshimura, H. Itabashi, and A. Shinohara, “Solvent extraction of Zr and Hf from HCl by Aliquat
336 using a flow-type extraction apparatus toward online chemical studies of element 104, rutherfordium,” Solv. Extr. Ion Exch 38,
318–327 (2020).
Z. Tsoodol, M. Aikawa, I. Dagvadorj, T. Khishigjargal, N. Javkhlantugs, Y. Komori, and H. Haba, “Production cross sections of 68 Ga andradioactive by-products in deuteron-induced reactions on natural zinc,” Appl. Radiat. Isot. 159, 109095-1–8 (2020).
M. Sakaguchi, M. Aikawa, M. Saito, N. Ukon, Y. Komori, and H. Haba, “Activation cross section measurement of the deuteron-induced
reaction on yttrium-89 for zirconium-89 production”, Nucl. Instrum. Methods Phys. Res. B 472, 59–63 (2020).
T. Niwase, M. Wada, P. Schury, H. Haba, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, K. Morimoto, K. Morita, M. Rosenbusch,
H. Wollnik, T. Shanley, and Y. Benari, “Development of an “α-TOF” detector for correlated measurement of atomic masses and decay
properties,” Nucl. Instrum. Methods Phys. Res. A 953, 163198-1–8 (2020).
J. Grund, M. Asai, K. Blaum, M. Block, S. Chenmarev, Ch. E. Düllmann, K. Eberhardt, S. Lohse, Y. Nagame, Sz. Nagy, P. Naubereit,
J. J. W. van de Laar, F. Schneider, T. K. Sato, N. Sato, D. Simonovski, K. Tsukada, and K. Wendt, “First online operation of TRIGATRAP,” Nucl. Instrum. Methods Phys. Res. A 972, 164013-1–8 (2020).
Y. Shigekawa, Y. Kasamatsu, Y. Yamakita, Y. Yasuda, E. Watanabe, N. Kondo, H. Haba, and A. Shinohara, “Development of a retardingfield type magnetic bottle spectrometer for studying the internal-conversion process of 235m U,” Nucl. Instrum. Methods Phys. Res. A
976, 164207-1–10 (2020).

[Review articles]
H. Haba, “The rewards and challenges of expanding the periodic table,” Chem. Eng. News, August 5, 36–37 (2019).
Ӌ৔޺ޫ, ʮୈ 8 प‫ظ‬ͷ৽‫ݩ‬ૉΛ‫ٻ‬Ίͯʯ, 40, 14–20 (2019).
Ӌ৔޺ޫ, ʮ೔ຊͷ‫ʹऀڀݚ‬ΑΔ৽‫ݩ‬ૉͷ୳ࡧͱप‫ظ‬දͷ։୓—χοϙχ΢Ϝ, 93 ൪‫ݩ‬ૉ, χϗχ΢Ϝ. ͞ΒͳΔ৽‫ݩ‬ૉΛ‫ٻ‬Ίͯ—ʯ,Խֶͱ޻‫ ۀ‬72, 944–945 (2019).
Ӌ৔޺ޫ, ʮཧ‫͚͓ʹݚ‬Δ֩ҩֶ࣏ྍ༻ϥδΦΞΠιτʔϓͷ੡଄ʯ, Drug Delivery Syst. 35, 114–120 (2020).
ւ໺߂ߦ, ּদྑਸ, ॏՏ༏େ, Ӌ৔޺ޫ, ฏ໦‫޺و‬, ૿ా޹඙, ࢁ‫ޱ‬ರ࢙, ԣ๺୎໵, ٢‫ݟ‬জ༸, ٢ଜߒ࢘, ʮߴً౓ X ઢΛ༻͍ͨ֩‫ڞ‬໐ࢄཚٕज़ʹΑΔ‫ ֩ࢠݪ‬229 Th ΞΠιϚʔঢ়ଶͷਓ޻ੜ੒ʯ, Isotope News No. 768, 2–6 (2020).

[Books]ࠤ౻๬, ޻౻‫ٱ‬ত, ʮ௒ॏ‫ݩ‬ૉͷ߹੒ʯ, in ʮϑϩϯςΟΞγϦʔζ 2 ௒ॏ‫ݩ‬ૉԽֶͷ࠷લઢʯ, Ӭ໨་Ұ࿠ʢฤஶʣ, pp. 6–13, ೔ຊ์- 346 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

ࣹԽֶձ, 2019 ೥ 9 ݄ 1 ೔.
๛ౢް࢙, Ӌ৔޺ޫ, ʮ௒ॏ‫ݩ‬ૉԽֶ—༹ӷԽֶʯ, in ʮϑϩϯςΟΞγϦʔζ 2 ௒ॏ‫ݩ‬ૉԽֶͷ࠷લઢʯ, Ӭ໨་Ұ࿠ʢฤஶʣ,pp. 41–48, ೔ຊ์ࣹԽֶձ, 2019 ೥ 9 ݄ 1 ೔.
ೆ෢ࢤ, ߴ‫ڮ‬࿨໵, ʮ‫ాژ‬Ҩ੻ 4 ۠ग़౔Ҩ෺෇ணਫۜगͷེԫಉҐମ෼ੳʯ, in ʮग़ӢࢢͷจԽࡒใࠂ 39 ‫ాژ‬Ҩ੻ 4 ۠ ൃ۷ௐࠪใ
ࠂॻʯ, ग़Ӣࢢ‫ڭ‬ҭҕһձ, pp. 165–168, 2019 ೥ 3 ݄.
Ӌ৔޺ޫʢ෼୲ࣥචʣ, ʮΞΠιτʔϓखா 12 ൛ʯ, ೔ຊΞΠιτʔϓ‫ڠ‬ձʢฤूɾൃߦʣ, ‫ؙ‬ળग़൛‫ࣜג‬ձࣾ, 2020 ೥ 3 ݄ 30 ೔.

[Proceedings]
H. Haba for RIKEN SHE Collaboration, “Present status and perspectives of SHE researches at RIKEN,” in “Proceedings of the international symposium on exotic nuclei, Petrozavodsk, Russia, 10–15 September 2018,” Yu. E. Penionzhkevich, Yu. G. Sobolev (Eds.),
World Scientific Publishing Co. Pte. Ltd., pp. 192–199 (2020).

Presentations[International conferences/workshops]
A. R. Usman, M. U. Khandaker, H. Haba, and N. Otuka (poster), “Cyclotron production cross sections of 61 Cu radionuclide fromnat
Ni(d, x)61 Cu nuclear reaction,” 2019 International Conference on Nuclear Data for Science and Technology (ND2019), Beijing,
China, May 19–24, 2019.
A. R. Usman, M. U. Khandaker, H. Haba, and N. Otuka (poster), “Towards formation of IAEA database for all metallic properties usefulin radionuclides production: eﬀect of varied titanium densities on excitation functions,” 2019 International Conference on Nuclear Data
for Science and Technology (ND2019), Beijing, China, May 19–24, 2019.
H. Haba (invited), “Production and applications of radioisotopes at RIKEN RI Beam Factory,” SHE Science Symposium, Oak Ridge,
USA, May 30, 2019.
H. Haba (invited), “Synthesis and chemistry of new elements at RIKEN,” 9th European Chemistry Congress, Berlin, Germany, June
17–18, 2019.
H. Kanda, T. Nakano, N. Aoi, M. H. Fukuda, T. Yorita, T. Suzuki, N. Takahashi, A. Shinohara, H. Haba, S. Kamigaito, H. Kikunaga,
H. Hama, T. Muto, H. Ikeda, H. Watabe, M. Itoh, H. Kawamura, Y. Sakemi, M. R. Zhang, K. Nagatsu, and H. Suzuki (oral), “Shortlived radioisotope supplying platform in Japan,” 39th Annual Conference of the Canadian Nuclear Society and 43rd Annual CNS/CNA
Student Conference, Ottawa, Canada, June 23–26, 2019.
T. Zolbadral, M. Aikawa, D. Ichinkhoroloo, K. Tegshjargal, N. Javkhlantugs, Y. Komori, and H. Haba (poster), “Production cross sectionsof 68 Ga and radioactive by-products in deuteron-induced reactions on natural zinc,” The 7th GI-CoRE Medical Science and Engineering
Symposium FLASH, MBA, & 4DRT, Hokkaido, Japan, August 18–19, 2019.
A. Yakushev, L. Lens, Ch. E. Düllmann, M. Asai, M. Block, H. Brand, H. M. David, J. Despotopulos, A. Di Nitto, K. Eberhardt, U. Forsberg, P. Golubev, M. Götz, S. Götz, H. Haba, L. Harkness-Brennan, W. Hartmann, R. -D. Herzberg, D. Hinde, J. Hoﬀmann, A. Hübner,
E. Jäger, M. Jourdan, D. Judson, J. Khuyagbaatar, B. Kindler, Y. Komori, J. Konki, J. V. Kratz, J. Krier, N. Kurz, M. Laatiaoui,
S. Lahiri, B. Lommel, M. Maiti, A. Mistry, Ch. Mokry, K. Moody, Y. Nagame, J. P. Omtvedt, P. Papadakis, V. Pershina, T. Reich,
D. Rudolph, J. Runke, L. Samiento, T. K. Sato, M. Schädel, P. Scharrer, B. Schausten, D. Shaughnessy, J. Steiner, P. Thörle-Pospiech,
A. Toyoshima, N. Trautmann, K. Tsukada, J. Uusitalo, K. -O. Voss, A. Ward, M. Wegrzecki, N. Wiehl, E. Williams, and V. Yakusheva(invited), “Chemical studies of superheavy elements at a recoil separator, with a focus on Fl,” 6th International Conference on theChemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
M. Götz, Ch. E. Düllmann, A. Yakushev, M. Asai, J. Ballof, A. Di Nitto, K. Eberhardt, S. Götz, H. Haba, E. Jäger, Y. Kaneya, Y. Komori,
J. V. Kratz, J. Krier, B. Lommel, A. Mitsukai, Y. Nagame, T. K. Sato, A. Toyoshima, K. Tsukada, V. Wolter, and V. Yakusheva (poster),“In-situ synthesis of volatile transition metal carbonyl complexes with short-lived radioisotopes,” 6th International Conference on theChemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
Z. Qin, Y. Wang, S. Cao, J. Zhang, J. Yang, H. Haba, F. Fan, Y. Komori, T. Yokokita, K. Morimoto, D. Kaji, Y. Wittwer, R. Eichler,
and A. Türler (poster), “The study of rhenium pentacarbonyl complexes using single-atom chemistry in gas phase,” 6th International
Conference on the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
Y. Wang, Y. Wittwer, J. Zhang, J. Yang, H. Haba, Y. Komori, T. Yokokita, S. Cao, F. Fan, R. Eichler, A. Türler, and Z. Qin (oral), “Thespecies identification of Mo, W, and Re carbonyl complexes with laserablation time-of-flight mass-spectrometry,” 6th International
Conference on the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
L. Lens, A. Yakushev, Ch. E. Düllmann, M. Asai, M. Block, H. Brand, M. Dasgupta, H. M. David, J. Despotopulos, A. Di Nitto,
K. Eberhardt, M. Götz, P. Golubev, S. Götz, H. Haba, L. Harkness-Brennan, F. P. Heßberger, R. -D. Herzberg, D. Hinde, J. Hoﬀmann,
A. Hübner, E. Jäger, D. Judson, J. Khuyagbaatar, B. Kindler, Y. Komori, J. Konki, J. V. Kratz, J. Krier, N. Kurz, M. Laatiaoui,
S. Lahiri, B. Lommel, M. Maiti, A. K. Mistry, C. Mokry, K. Moody, Y. Nagame, J. P. Omtvedt, P. Papadakis, V. Pershina, A. Roth,
D. Rudolph, J. Runke, L. Sarmiento, M. Schädel, P. Scharrer, T. Sato, D. Shaughnessy, B. Schausten, J. Steiner, P. Thörle-Pospiech,
N. Trautmann, K. Tsukada, J. Uusitalo, A. Ward, M. Wegrzecki, E. Williams, N. Wiehl, V. Yakusheva (poster), “Optimizations of the
TASCA-COMPACT setup towards chemical studies of nihonium (element 113),” 6th International Conference on the Chemistry andPhysics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
T. Niwase, M. Wada, P. Schury, Y. Ito, S. Kimura, D. Kaji, M. Rosenbusch, Y. Watanabe, Y. Hirayama, H. Miyatake, J. Y. Moon,
H. Ishiyama, K. Morimoto, H. Haba, T. Tanaka, S. Ishizawa, A. Takamine, K. Morita, and H. Wollnik (poster), “Development and first
results from a novel “α-ToF” detector used with a multi-reflection time-of-flight mass spectrograph,” 6th International Conference on
the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
T. Tanaka, K. Morita, K. Morimoto, D. Kaji, H. Haba, R. A. Boll, N. T. Brewer, S. V. Cleve, D. J. Dean, S. Ishizawa, Y. Ito, Y. Komori,- 347 -

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K. Nishio, T. Niwase, B. C. Rasco, J. B. Roberto, K. Rykaczewski, H. Sakai, D. W. Stracener, and K. Hagino (oral), “Fusion dynamics
for hot fusion reactions revealed in quasielastic barrier distributions,” 6th International Conference on the Chemistry and Physics of theTransactinide Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
M. Wada, P. Schury, H. Miyatake, Y. X. Watanabe, Y. Hirayama, H. Wollnik, S. Kimura, S. Ishizawa, T. Niwase, M. Rosenbusch, D. Kaji,
K. Morimoto, H. Haba, I. Takamine, T. Tanaka, H. Ishiyama, Y. Ito, J. Y. Moon, and K. Morita (invited), “SHE-Mass-II setup for direct
mass measurement of hot-fusion superheavy nuclides,” 6th International Conference on the Chemistry and Physics of the Transactinide
Elements (TAN19), Wilhelmshaven, Germany, August 25–30, 2019.
Y. Ito, P. Schury, M. Wada, F. Arai, H. Haba, Y. Hirayama, S. Ishizawa, D. Kaji, S. Kimura, H. Koura, M. Maccormick, H. Miyatake,J. -Y. Moon, K. Morimoto, K. Morita, M. Mukai, I. Murray, T. Niwase, K. Okada, A. Ozawa, M. Rosenbusch, A. Takamine, T. Tanaka,
Y. Watanabe, H. Wollnik, and S. Yamaki (oral), “Direct mass measurements of mendelevium isotopes in the vicinity of the N =152 deformed shell-closure,” 6th International Conference on the Chemistry and Physics of the Transactinide Elements (TAN19),
Wilhelmshaven, Germany, August 25–30, 2019.
M. Okamura (oral), E. Beebe, S. Ikeda, T. Kanesue, D. Raparia, and H. Haba, “96 Zr beam production for isobar experiment in RHIC,”
The 18th International Conference on Ion Sources (ICIS’19), Lanzhou, China, September 1–6, 2019.
H. Haba (invited), “Present status and perspectives of superheavy element researches at RIKEN,” XXXVI’th Mazurian Lakes Conference
on Physics, Piaski, Poland, September 1–7, 2019.
H. Haba (invited), “RI production—Chemistry of new elements to diagnosis and treatment of cancer—,” Tsukuba Conference 2019,
Tsukuba, Japan, October 2–4, 2019.
T. Fukuchi, M. Shigeta, H. Haba, S. Yamamoto, and Y. Watanabe (poster), “Imaging performance evaluation of a multiple-isotope PET
with 44m Sc tracer,” 2019 IEEE Nuclear Science Symposium (NSS) and Medical Imaging Conference (MIC), Manchester, UK, October
26–November 2, 2019.
T. Zolbadral, M. Aikawa, D. Ichinkhoroloo, T. Khishigjargal, Y. Komori, H. Haba, S. Takács, F. Ditrói, and Z. Szűcs (poster), “Production
cross sections of 45 Ti via deuteron-induced reaction on scandium,” 2019 Symposium on Nuclear Data, Fukuoka, Japan, November
28–30, 2019.
M. Saito, M. Aikawa, T. Murata, Y. Komori, H. Haba, S. Takács, F. Ditrói, and Z. Szűcs (poster), “Production of 169 Yb by the protoninduced reaction on 169 Tm,” 2019 Symposium on Nuclear Data, Fukuoka, Japan, November 28–30, 2019.
Y. Kasamatsu, H. Ninomiya, S. Hayami, M. Nagase, E. Watanabe, Y. Shigekawa, N. Kondo, H. Haba, T. Yokokita, Y. Komori, D. Mori,Y. Wang, K. Ghosh, M. Kaneko, and A. Shinohara (poster), “Coprecipitation of nobelium with samarium hydroxide,” The 4th International Symposium on Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
E. Watanabe, S. Hayami, K. Tonai, H. Ninomiya, K. Ouchi, Y. Kasamatsu, Y. Kitagawa, M. Nakano, Y. Shigekawa, T. Yokokita, and
A. Shinohara (poster), “Anion-exchange Experiment of Zr, Hf, and Th in HNO3 ,” The 4th International Symposium on Superheavy
Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
Z. Qin, Y. Wang, S. W. Cao, J. C. Zhang, F. L. Fang, J. Yang, H. Haba, Y. Komori, T. Yokokita, K. Morimoto, D. Kaji, Y. Wittwer,
R. Eichler, and A. Türler (invited), “Towards the bohrium carbonyl complexes in gas phase,” The 4th International Symposium on
Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
Y. Wang, Y. Wittwer, J. Zhang, S. Cao, Y. Komori, T. Yokokita, Y. Shigekawa, F. Fan, J. Yang, H. Haba, R. Eichler, A. Türler, and Z. Qin(oral), “Species identification of Re carbonyls using laser-ablation time-of-flight mass-spectrometer,” The 4th International Symposiumon Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
T. Yokokita, Y. Kasamatsu, E. Watanabe, Y. Komori, H. Ninomiya, Y. Wang, D. Mori, K. Ghosh, A. Shinohara, and H. Haba (oral),“Anion exchange of Rf, Zr, Hf, and Th in H2 SO4 ,” The 4th International Symposium on Superheavy Elements (SHE2019), Hakone,
Japan, December 1–5, 2019.
T. Niwase, M. Wada, P. Schury, Y. Ito, S. Kimura, D. Kaji, M. Rosenbusch, Y. X. Watanabe, Y. Hirayama, H. Miyatake, J. Y. Moon,
H. Ishiyama, K. Morimoto, H. Haba, T. Tanaka, S. Ishizawa, A. Takamine, K. Morita, and H. Wollnik (oral), “Correlation measurement of precision mass and decay properties of nuclei via MRTOF-MS with α-ToF detector,” The 4th International Symposium on
Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
M. Rosenbusch, M. Wada, P. Schury, S. Iimura, H. Haba, Y. Hirayama, H. Ishiyama, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, J. Y. Moon, K. Morimoto, T. Tanaka, T. Niwase, A. Takamine, K. Morita, Y. X. Watanabe, and H. Wollnik (oral), “Dynamic
ejection-field correction for MR ToF mass spectrometry of SHE using arbitrary mass references,” The 4th International Symposium on
Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
H. Haba (plenary), “Production and applications of radioisotopes at RIKEN RI Beam Factory—Search for new elements through diagnosis
and therapy of cancer—,” The 10th International Conference on Isotopes (10ICI), Kuala Lumpur, Malaysia, February 3–7, 2020.
H. Haba (invited), “Present status and perspectives of superheavy element chemistry at RIKEN,” The 10th International Conference on
Isotopes (10ICI), Kuala Lumpur, Malaysia, February 3–7, 2020.
Y. Komori, M. Murakami, and H. Haba (oral), “Measurements of excitation functions for the nat W(d, x) reactions based on new half-livesof rhenium isotopes,” The 10th International Conference on Isotopes (10ICI), Kuala Lumpur, Malaysia, February 3–7, 2020.

[Seminars]
H. Haba, “Production of radioisotopes for application Studies at RIKEN RI Beam Factory,” Seminar at Institute of Modern Physics (IMP),
Lanzhou, China, August 12, 2019.
H. Haba, “Production of radioisotopes for application Studies at RIKEN RI Beam Factory,” IFIN-HH Seminar at Horia Hulubei National
Institute for R&D in Physics and Nuclear Engineering, Bucharest, Rumania, October 21, 2019.
Y. Komori, “Aqueous chemistry of superheavy elements at RIKEN,” IFIN-HH Seminar at Horia Hulubei National Institute for R&D in- 348 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Physics and Nuclear Engineering, Bucharest, Rumania, October 21, 2019.
H. Haba, “Production of radioisotopes for application studies at RIKEN RI Beam Factory”, Seminar at Sunway University, Selangor,
Malaysia, February 10, 2020.
Y. Komori, “Excitation function measurements in RIKEN”, Seminar at Sunway University, Selangor, Malaysia, February 10, 2020.

[Domestic conferences/workshops]
෱஍஌ଇ, ॏాඒ߳, Ӌ৔޺ޫ, ࢁຊ੣Ұ, ౉ล‫ྑګ‬, ӿຊलҰʢ‫ޱ‬಄ൃදʣ, ʮཅిࢠ–ΨϯϚઢ์ग़֩ 44 Sc Λ༻͍ͨෳ਺τϨʔαʔPET Πϝʔδϯάʯ, ೔ຊ෼ࢠΠϝʔδϯάֶձୈ 14 ճ૯ձɾֶज़ूձ, ࡳຈ, 2019 ೥ 5 ݄ 23–24 ೔.
౻Ҫത࢙, େ؏࿨৴, ∁ౡେً, ‫ݹ‬լએউ, ௡ଜྒྷ, দଜอ޿, Ӌ৔޺ޫ, Wang Yang, Kaustab Ghosh, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େً,ᚸು࢙೫ʢϙελʔൃදʣ, ʮҩྍࢪઃͰͷ α ઢ์ग़֩छ 211 At ͷଌఆ‫ܥ‬ͷߏஙʯ, ೔ຊ෼ࢠΠϝʔδϯάֶձୈ 14 ճ૯ձɾֶज़
ूձ, ࡳຈ, 2019 ೥ 5 ݄ 23–24 ೔.
ຊଜ৴࣏, ‫ت‬Ҫ‫܄‬, Ӌ৔޺ޫ, ༀࢣࣉलथ, ౉ล‫ྑګ‬, ӿຊलҰʢ‫ޱ‬಄ൃදʣ, ʮ൒ಋମίϯϓτϯΧϝϥ GREI ʹΑΔ Na+ /K+ ͷಉ࣌Πϝʔδϯάʯ, ೔ຊ෼ࢠΠϝʔδϯάֶձୈ 14 ճ૯ձɾֶज़ूձ, ࡳຈ, 2019 ೥ 5 ݄ 23–24 ೔.
৿େً, ԣ๺୎໵, খ৿༗‫ࢠر‬, Ԧ༸, Ӌ৔޺ޫ, ਆాߊॆ, ࿬୩༤Ұ࿠, দຊ‫װ‬༤, ໦ଜढ़෉ʢ‫ޱ‬಄ൃදʣ,ʮཧ‫͚͓ʹݚ‬Δ൦෍༻ਫ਼੡
42, 43K ͓Αͼ 44m Sc ͷ੡଄ٕज़։ൃʯ, ୈ 56 ճΞΠιτʔϓɾ์ࣹઢ‫ൃڀݚ‬දձ, จ‫ژ‬, 2019 ೥ 7 ݄ 3–5 ೔.
ॏՏ༏େʢ‫ޱ‬಄ൃදʣ, ʮ235m U ͱ 229m Th ͷ಺෦స‫׵‬աఔʹର͢ΔԽֶޮՌʯ, ୈ 58 ճ֩ԽֶՆͷֶߍ, ༝෍, 2019 ೥ 9 ݄ 11–14 ೔.
খ৿༗‫ࢠر‬ʢ‫ޱ‬಄ൃදʣ, ʮཧ‫ݚ‬ͷ֩Խֶ‫ڥ؀ڀݚ‬ʯ, ୈ 58 ճ֩ԽֶՆͷֶߍ, ༝෍, 2019 ೥ 9 ݄ 11–14 ೔.
ᜊ౻๖ඒ, ߹઒ਖ਼޾, ࡔ‫ޱ‬ཧ࠸, ӈۙ௚೭, খ৿༗‫ࢠر‬, Ӌ৔޺ޫ, λΧοναϯυʔϧʢ‫ޱ‬಄ൃදʣ, ʮՙిཻࢠೖࣹ൓Ԡʹ͓͚Δҩ
ྍ༻์ࣹੑ֩छ 169 Yb ੜ੒அ໘ੵଌఆ࣮‫ݧ‬ʯ, ೔ຊ‫ֶྗࢠݪ‬ձ 2019 ೥ळͷେձ, ෋ࢁ, 2019 ೥ 9 ݄ 11–13 ೔.
ଜా๎େ, ߹઒ਖ਼޾, ࡔ‫ޱ‬ཧ࠸, Ӌ৔޺ޫ, খ৿༗‫ࢠر‬, λΧναϯυʔϧ, ϑΣϨϯνσΟτϩΠ, ζʔνκϧλϯʢ‫ޱ‬಄ൃදʣ, ʮDyඪత΁ͷΞϧϑΝཻࢠরࣹʹΑΔ 166 Ho ͷྭ‫਺ؔى‬ଌఆʯ, ೔ຊ‫ֶྗࢠݪ‬ձ 2019 ೥ळͷେձ, ෋ࢁ, 2019 ೥ 9 ݄ 11–13 ೔.
ࡔ‫ޱ‬ཧ࠸, ߹઒ਖ਼޾, ᜊ౻๖ඒ, ӈۙ௚೭, খ৿༗‫ࢠر‬, Ӌ৔޺ޫʢ‫ޱ‬಄ൃදʣ, ʮ89 Zr ੜ੒Λ໨తͱͨ͠ 89 Y ഩ΁ͷॏཅࢠরࣹʹ͓
͚Δੜ੒அ໘ੵͷଌఆʯ, ೔ຊ‫ֶྗࢠݪ‬ձ 2019 ೥ळͷେձ, ෋ࢁ, 2019 ೥ 9 ݄ 11–13 ೔.
I. Dagvadorj, M. Aikawa, T. Zolbadral, Y. Komori, H. Habaʢ‫ޱ‬಄ൃදʣ, ʮProduction cross sections of dysprosium radioisotopes indeuteron-induced reactions on natural terbium up to 24 MeVʯ, ೔ຊ‫ֶྗࢠݪ‬ձ 2019 ೥ळͷେձ, ෋ࢁ, 2019 ೥ 9 ݄ 11–13 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ৽‫ݩ‬ૉԽֶͷల๬ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑ଠ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnikʢ‫ޱ‬಄ൃදʣ, ʮMRTOF-MS Λ༻͍ͨ 207 Ra ͷਫ਼ີ࣭ྔ—่յಛੑଌఆʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
૿ా޹඙, Kjeld Beeks, Ӌ৔޺ޫ, ‫ݪ‬ल໌, ฏ໦‫޺و‬, ౻ࢬ྄, ౻ຊ߂೭, ླ໦݈ଠ, ւ໺߂ߦ, ּদྑਸ, ๺ඌਅ࢘, খແ݈࢘, ‫ٶ‬ຊ༞थ,ԬҪߊҰ, ࡫ඌొ, ࠤ౻ଳࢠ, Thorsten Schumm, ੉‫ށ‬੣, ॏՏ༏େ, Simon Stellmer, ‫࣏ݡ࡞ۄ‬, ২஛ஐ, ౉෦৴, ౉෦࢘, ࢁ‫ޱ‬ರ࢙,҆ా༐ً, ґా๕୎, ٢‫ݟ‬জ༸, ٢ଜߒ࢘, ٢ଜଠ඙ʢ‫ޱ‬಄ൃදʣ, ʮτϦ΢Ϝ 229 ‫֩ࢠݪ‬ҟੑମ͔Βͷਅۭࢵ֎ޫ‫؍‬ଌͷ‫ݱ‬ঢ়ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17–20 ೔.
౉ᬒӯհ, ଎ਫᠳ, ౦಺ࠀഅ, ּদྑਸ, ๺Տ߁ོ, ॏՏ༏େ, ԣ๺୎໵, த໺խ༝, ࣰ‫ްݪ‬ʢϙελʔൃදʣ, ʮ঳ࢎதʹ͓͚Δ Zr, Hf͓Αͼ Th ͷࡨ‫ܗ‬੒ʹؔ͢Δ࣮‫ݧ‬ɾཧ࿦‫—ڀݚ‬௒ॏ‫ݩ‬ૉ Rf ͷԽֶ‫—͚ͯ޲ʹڀݚ‬ʯ, ୈ 13 ճ෼ࢠՊֶ౼࿦ձ 2019 ໊‫ݹ‬԰, ໊‫ݹ‬԰, 2019 ೥ 9 ݄ 17–20 ೔.
ૣ઒༏ଠ, ࡔ‫ޱ‬ҁ, ଜాਅ༏, দଜՆ‫ل‬, ౻পमฏ, தౡ࿕‫ٱ‬, ּদྑਸ, ࣰ‫ްݪ‬, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େً, ໼ೲ৻໵, Ӌ৔޺ޫ,ԣࢁ໌඙ʢ‫ޱ‬಄ൃදʣ, ʮU+p ‫ ͼٴ‬Th+Li ൓ԠʹΑΔ Np ಉҐମྭ‫਺ؔى‬ͷ࡞੒ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ
͖, 2019 ೥ 9 ݄ 24–26 ೔.
খ৿༗‫ࢠر‬, ଜ্ণ࢙, Ӌ৔޺ޫʢ‫ޱ‬಄ൃදʣ, ʮnat W(d, x) ൓ԠʹΑΔ Re ಉҐମͷྭ‫ͱ਺ؔى‬൒‫ظݮ‬ͷଌఆʯ, ೔ຊ์ࣹԽֶձୈ 63ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
Y. Wang, N. Sato, Y. Komori, T. Yokokita, D. Mori, S. Usuda, H. Habaʢ‫ޱ‬಄ൃදʣ, ʮProduction of At-211 at RIKENʯ, ೔ຊ์ࣹԽֶ
ձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ԣ๺୎໵, ּদྑਸ, ౉ᬒӯհ, খ৿༗‫ࢠر‬, ೋ‫ٶ‬लඒ, Ԧ༸, ৿େً, ΰʔγϡίʔελϒ, ࣰ‫ް ݪ‬, Ӌ৔޺ޫʢ‫ޱ‬಄ൃදʣ, ʮེࢎ‫ܥ‬ʹ͓͚Δ Rf ͷӄΠΦϯަ‫׵‬ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
౉ᬒӯհ, ଎ਫᠳ, ౦಺ࠀഅ, ೋ‫ٶ‬लඒ, ּদྑਸ, ๺Տ߁ོ, ॏՏ༏େ, ԣ๺୎໵, த໺խ༝, ࣰ‫ްݪ‬ʢ‫ޱ‬಄ൃදʣ, ʮZr, Hf, Th ͷ঳ࢎࡨମ‫ܗ‬੒ʹؔ͢Δ࣮‫͓ݧ‬Αͼཧ࿦‫ ڀݚ‬Rf ͷԽֶʹ޲͚ͯ ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
଎ਫᠳ, ೋ‫ٶ‬लඒ, ౉ᬒӯհ, ॏՏ༏େ, Ӭ੉কߒ, ּদྑਸ, ۙ౻੒ඒ, Ӌ৔޺ޫ, ԣ๺୎໵, খ৿༗‫ࢠر‬, ৿େً, Ԧ༸, ΰʔγϡίʔελϒ, ࠤ౻๬, ࣰ‫ްݪ‬ʢ‫ޱ‬಄ൃදʣ, ʮਫࢎԽαϚϦ΢Ϝ‫ڞ‬௜๏Λ༻͍ͨ 102 ൪‫ݩ‬ૉϊʔϕϦ΢Ϝͷ௜఼࣮‫ݧ‬ʯ, ೔ຊ์ࣹԽֶձ
ୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ॏՏ༏େ, ּদྑਸ, ࢁ๺Ղ޺, ۚࢠ੓ࢤ, ౉ᬒխ೭, ౉ᬒӯհ, ҆ా༐ً, ۙ౻੒ඒ, ࣰ‫ްݪ‬ʢ‫ޱ‬಄ൃදʣ, ʮࢎԽ෺ɾϑοԽ෺ɾԘԽ
෺‫͚͓ʹܥ‬Δ U-235m ͷ൒‫͓ظݮ‬Αͼ಺෦స‫ࢠి׵‬ΤωϧΪʔεϖΫτϧͷଌఆʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ॏՏ༏େ, ּদྑਸ, ౉ᬒӯհ, ҆ా༐ً, ۙ౻੒ඒ, ೋ‫ٶ‬लඒ, ଎ਫᠳ, Ӌ৔޺ޫ, ࣰ‫ްݪ‬ʢ‫ޱ‬಄ൃදʣ, ʮAc-229 ͷ β ઢ—ిࢠಉ࣌‫਺ܭ‬ଌఆʹΑΔ Th-229m ͷ಺෦స‫ࢠి׵‬ͷ‫؍‬ଌʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ߴๆѪࢠ, ৿ాߒհ, H. Wollnikʢ‫ޱ‬಄ൃදʣ, ʮMRTOF + α-TOF Λ༻͍ͨ 207 Ra ͷ࣭ྔ–่յಛੑଌఆʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
Ӎ૔‫ܒ‬, ळࢁ࿨඙, Ӌ৔޺ޫ, ‫ٱ‬෌໦ࢤ࿠ʢ‫ޱ‬಄ൃදʣ, ʮϥϯλϊΠυ಺แϑϥʔϨϯʢLn3+ @C82 3− ʣʹ͓͚Δ಺แۚଐ‫୸͕ࢠݪ‬ૉέʔδʹ‫ઁ͢΅ٴ‬ಈతӨ‫ڹ‬ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
੨Ҫ‫౎ܠ‬, ৽༟‫و‬, ઒㟒߁ฏ, ౦ඒཬ, ࿯ࢁ޾৴, ੢தҰ࿕, Ӌ৔޺ޫ, ৿େً, Yang Wang, ԣࢁ໌඙ʢϙελʔൃදʣ, ʮRn-211/At-211- 349 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

δΣωϨʔλγεςϜʹඞཁͳ 207 Po আ‫ڈ‬๏ͷ‫ݕ‬౼ʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
҆ୡασΟΞ, ຤໦‫ܒ‬հ, ๛ౢް࢙, ௩ా࿨໌, Ӌ৔޺ޫ, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େًʢϙελʔൃදʣ, ʮHF/HNO3 ਫ༹ӷதʹ
͓͚Δ Nb, Ta, Pa ͷӄΠΦϯަ‫ݧ࣮׵‬ʙDb ϑοԽ෺ࡨମͷਪఆʹ޲͚ͯʙʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖,2019 ೥ 9 ݄ 24–26 ೔.
৿ాྋխ, ૣ઒༏ଠ, খ৿༗‫ࢠر‬, ԣ๺୎໵, ৿େً, Ӌ৔޺ޫ, ּদྑਸ, ࣰ‫ްݪ‬, ԣࢁ໌඙ʢϙελʔൃදʣ, ʮ239 Np ෳ߹֩‫͓ʹܥ‬͚Δ֩෼྾அ໘ੵଌఆʹΑΔ‫ي‬ಓ֯ӡಈྔͷਪఆʯ, ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձʢ2019ʣ, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ԣ๺୎໵ʢ‫ޱ‬಄ൃදʣ, ʮ৽‫ن‬ΨϯϚઢΠϝʔδϯά༻ϓϩʔϒ K-42, K-43 ‫ ͼٴ‬Sc-44m ͷ੡଄ʯ, ୈೋճ Chemical Probe ߹ಉ߹॓ηϛφʔ, ཛྷࢁொ, 2019 ೥ 10 ݄ 8–9 ೔.
খ৿༗‫ࢠر‬ʢϙελʔൃදʣ, ʮ༗༻ RI ϓϩʔϒ੡଄ʹ޲͚ͨ֩൓Ԡྭ‫਺ؔى‬ͷଌఆʯ, ୈೋճ Chemical Probe ߹ಉ߹॓ηϛφʔ,ཛྷࢁொ, 2019 ೥ 10 ݄ 8–9 ೔.
Y. Wangʢϙελʔൃදʣ, ʮProduction of a therapeutic isotope, astatine-211 at RIBFʯ, ୈೋճ Chemical Probe ߹ಉ߹॓ηϛφʔ, ཛྷࢁொ, 2019 ೥ 10 ݄ 8–9 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ৽‫ݩ‬ૉΛ୳ͦ͏! ʯ, ೔ຊԽֶձ ‫ͪͨ܅‬ͷকདྷͱԽֶͷະདྷ ౦େͰա͢͝Խֶͳि຤, จ‫ژ‬, 2019 ೥ 10 ݄
20 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ113 ൪χϗχ΢Ϝͷൃ‫ݟ‬ʯ, ࠃࡍप‫ظ‬ද೥ 2019 ಛผలΦʔϓχϯάΠϕϯτ, ࢁ‫ܗ‬, 2019 ೥ 11 ݄ 3 ೔.
ՖԬ޺࢙, େౡ߁޺, ླ໦ത‫ݩ‬, ࠤʑ໦Ұ࿠, ౉ลໜथ, Ӌ৔޺ޫ, ߥ໺ହ, ੴԬయࢠ, ରഅٛਓʢ‫ޱ‬಄ൃදʣ, ʮAt-211 ඪࣝ α ϝνϧ–ϑΣχϧΞϥχϯΛ༻͍ͨ಺༻์ࣹઢྍ๏ʯ, ೔ຊ֩ҩֶձୈ 61 ճֶज़૯ձ, দࢁ, 2019 ೥ 11 ݄ 4–6 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮ‫ݩ‬ૉΛͭ͘Ζ͏! ʯ, αΠΤϯεΞΰϥࠃࡍप‫ظ‬ද೥ಛผ‫ا‬ը‫ݩ‬ૉ‫ݕ‬ఆ 2019@౦‫ژ‬, ߐ౦, 2019 ೥ 11 ݄
16 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮϥδΦΞΠιτʔϓͷ੡଄ͱԠ༻—৽‫ݩ‬ૉͷ୳ࡧ͔Β͕Μͷ਍அɾ࣏ྍ·Ͱ—ʯ, 2019 ೥౓೔ຊΞΠιτʔϓ‫ڠ‬ձγϯϙδ΢ϜʮPETɾΠϝʔδϯά‫ڀݚ‬ͷ࠷લઢʙϥΠϑαΠΤϯεͱཧ޻ֶͷ༥߹ʙʯ, ઒࡚, 2019 ೥ 11 ݄ 22 ೔.
ߴ‫ڮ‬࿨໵ʢ‫ج‬ௐߨԋʣ, ʮ‫ۃ‬ඍྔͷེԫಉҐମൺ෼ੳʹΑΔ, Ҩ੻͔Βग़౔ͨ͠ਫۜगͷ࢈஍ಉఆʯ, ೔ຊ෼ੳԽֶձ ୈ 370 ճΨεΫϩϚτάϥϑΟʔ‫ڀݚ‬ձಛผߨԋձ, ๺, 2019 ೥ 11 ݄ 22 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ, ʮଟޫࢠΨϯϚઢ์ग़֩छͷ੡଄ʯ, ʮଟޫࢠΨϯϚઢ࣌ؒ/ۭؒ૬ؔ‫ܕ‬அ૚ࡱ૾๏ͷ‫ڀݚ‬ʯϫʔΫγϣοϓ,ߓ, 2019 ೥ 12 ݄ 6 ೔.
∁ౡେً, ‫ݹ‬լએউ, େ؏࿨৴, ᚸು࢙೫, ௡ଜྒྷ, ҆੢ߴኍ, ‫ాؠ‬๬, Wang Yang, ԣ๺୎໵, খ৿༗‫ࢠر‬, ৿େً, Ӌ৔޺ޫ, ౻Ҫത࢙,দଜอ޿ʢϙελʔൃදʣ, ʮΞϧϑΝઢ์ग़֩छΞελνϯ-211 Λ༻͍ͨ์ࣹ໔Ӹྍ๏ͷ։ൃʯ, ୈ 5 ճ AMED ͕Μएख‫ڀݚ‬ऀϫʔΫγϣοϓ, ઍ୅ా, 2020 ೥ 1 ݄ 9 ೔.
Ӌ৔޺ޫʢট଴ߨԋʣ,ʮཧ‫͚͓ʹݚ‬ΔϥδΦΞΠιτʔϓͷ੡଄ͱԠ༻ʙ৽‫ݩ‬ૉͷ୳ࡧ͔Β͕Μͷ਍அɾ࣏ྍ·Ͱʙʯ, ୈ 75 ճ์ࣹઢ‫ܭ‬ଌ‫ڀݚ‬ձ, ࿨ޫ, 2020 ೥ 1 ݄ 18 ೔.
ߴ‫ߒڮ‬೭, ౡఴ݈࣍, ‫ܓాח‬, Ӌ৔޺ޫ, ඦ੉හޫʢ‫ޱ‬಄ൃදʣ,ʮଟޫࢠΨϯϚઢ࣌ؒɾۭؒ૬ؔ‫ܕ‬Πϝʔδϯά๏ͷ‫ ڀݚ‬1ʢ֓ཁʣʯ,2020 ೥ୈ 67 ճԠ༻෺ཧֶձय़‫ֶق‬ज़ߨԋձ, ઍ୅ా, 2020 ೥ 3 ݄ 12–15 ೔.
‫ܓాח‬, ۚ‫ܟ‬᭪, ٢໺কੜ, ঙࢠҭ޺, ࢁ࿏ߊ߂, ࠇᖒढ़հ, ԣా༗ҝ, େ‫ڮ‬༤ೋ, ౡఴ݈࣍, ߴ‫ڮ‬ඒ࿨ࢠ, Ӌ৔޺ޫ, ඦ੉හޫ, ߴ‫ߒڮ‬೭, ٢઒জʢ‫ޱ‬಄ൃදʣ, ʮଟޫࢠΨϯϚઢ࣌ؒɾۭؒ૬ؔ‫ܕ‬Πϝʔδϯά๏ͷ‫ ڀݚ‬2ʢγϯνϨʔλ։ൃʣʯ, 2020 ೥ୈ 67 ճԠ༻෺ཧֶձय़‫ֶق‬ज़ߨԋձ, ઍ୅ా, 2020 ೥ 3 ݄ 12–15 ೔.
Ӌ৔޺ޫ, ৿େً, খ৿༗‫ࢠر‬, ԣ๺୎໵, Ԧ༸, ߴ‫ߒڮ‬೭, ౡఴ݈࣍, ‫ܓాח‬, ඦ੉හޫ, ߴ‫ڮ‬ඒ࿨ࢠʢ‫ޱ‬಄ൃදʣ, ʮଟޫࢠΨϯϚઢ࣌ؒɾۭؒ૬ؔ‫ܕ‬Πϝʔδϯά๏ͷ‫ ڀݚ‬3ʢRI ੡଄ʣʯ, 2020 ೥ୈ 67 ճԠ༻෺ཧֶձय़‫ֶق‬ज़ߨԋձ, ઍ୅ా, 2020 ೥ 3 ݄
12–15 ೔.
େ৊݈Ұ࿕, ҪԼහ޹, Ԭ࡚‫ل‬༤, ‫ܡࢁݹ‬ଠ࿠, ߴ‫ڮ‬ඒ࿨ࢠ, ඦ੉හޫ, ߴ‫ߒڮ‬೭, ౡఴ݈࣍, ‫ܓాח‬, Ӌ৔޺ޫʢ‫ޱ‬಄ൃදʣ, ʮଟޫࢠΨϯϚઢ࣌ؒɾۭؒ૬ؔ‫ܕ‬Πϝʔδϯά๏ͷ‫ ڀݚ‬4ʢҩྍԠ༻ʣʯ, 2020 ೥ୈ 67 ճԠ༻෺ཧֶձय़‫ֶق‬ज़ߨԋձ, ઍ୅ా, 2020
೥ 3 ݄ 12–15 ೔.
্ϊொਫ‫ل‬, Zhong Zhihong, େ৊݈Ұ࿠, ౡఴ݈࣍, ߴ‫ߒڮ‬೭, ‫ܓాח‬, Ӌ৔޺ޫ, ߴ‫ڮ‬ඒ࿨ࢠ, ඦ੉හޫʢ‫ޱ‬಄ൃදʣ, ʮଟޫࢠΨϯϚઢ࣌ؒɾۭؒ૬ؔ‫ܕ‬Πϝʔδϯά๏ͷ‫ ڀݚ‬5ʢγεςϜ։ൃʣʯ, 2020 ೥ୈ 67 ճԠ༻෺ཧֶձय़‫ֶق‬ज़ߨԋձ, ઍ୅ా, 2020
೥ 3 ݄ 12–15 ೔.
খᖒ௚໵, ௕ᖛ߂‫ق‬, ૣਫ༑༸, தଜ‫ܓ‬༎, খߴ߁র, ాத߳௡ੜ, େ௩ະདྷ, খ৿༗‫ࢠر‬, ࢢ઒༤Ұ, Ӌ৔޺ޫ, ্໺लथ, ञ‫ݟ‬ହ‫׮‬ʢ‫ޱ‬಄ൃදʣ,ʮϑϥϯγ΢Ϝ‫ࢠݪ‬ͷి‫ؾ‬૒‫ࢠۃ‬ೳ཰୳ࡧͷͨΊͷද໘ి཭ΠΦϯ‫ݯ‬ͷ։ൃʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020೥ʣ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
ࡔ౦༎੕, ੨໦ঊ, ᓎҪതّ, ৽૔५, ླ໦େհ, Ӌ৔޺ޫʢ‫ޱ‬಄ൃදʣ,ʮ์ࣹԽ๏ʹΑΔଟதੑࢠ‫֩ࢠݪ‬ͷ୳ࡧʯ, ೔ຊ෺ཧֶձୈ
75 ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
ւ໺߂ߦ, Ӌ৔޺ޫ, ‫ݪ‬ल໌, ฏ໦‫޺و‬, ౻ࢬ྄, ౻ຊ߂೭, ּদྑਸ, ๺ඌਅ࢘, খແ݈࢘, ૿ా޹඙, ‫ٶ‬ຊ༞थ, ԬҪߊҰ, ࡫ඌొ,Kjeld Beeks, Thorsten Schumm, ੉‫ށ‬੣, ॏՏ༏େ, A. Simon Stellmer, ‫࣏ݡ࡞ۄ‬, ২஛ஐ, ౉෦৴, ౉෦࢘, ࢁ‫ޱ‬ರ࢙, ҆ా༐ً, ґా๕୎, ٢‫ݟ‬জ༸, ٢ଜߒ࢘, ٢ଜଠ඙ʢ‫ޱ‬಄ൃදʣ, ʮτϦ΢Ϝ 229 ΞΠιϚʔ४Ґ͔Βͷਅۭࢵ֎ޫͷ୳ࡧʯ, ೔ຊ෺ཧֶձୈ 75ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.
ఉ੉‫ོڿ‬, ࿨ాಓ࣏, P. Schury, ҏ౻༝ଠ, ໦ଜ૑େ, Ճ࣏େ࠸, M. Rosenbusch, ౉ล༟, ฏࢁլҰ, ‫ٶ‬෢Ӊ໵, J. Y. Moon, ੴࢁത߃,৿ຊ޾࢘, Ӌ৔޺ޫ, ాதହ‫و‬, ੴᖒྙ, ൧ଜढ़, ߴๆѪࢠ, ৿ాߒհ, H. Wollnikʢ‫ޱ‬಄ൃදʣ,ʮMRTOF+α-TOF Λ༻͍ͨ୹ण໋ α่յ֩छͷ࣭ྔ-่յಛੑଌఆʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձʢ2020 ೥ʣ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16–19 ೔.

Awards৿େً, ʮཧ‫͚͓ʹݚ‬Δ൦෍༻ਫ਼੡ 42, 43 K ͓Αͼ 44m Sc ͷ੡଄ٕज़։ൃʯ, ୈ 56 ճΞΠιτʔϓɾ์ࣹઢ‫ൃڀݚ‬දձ एख༏लߨԋ৆, 2019 ೥ 7 ݄ 4 ೔.
N. Sato, “Awards the Element NIHONIUM”, Periodic Table of Younger Chemists, International Union of Pure and Applied Chemistry,- 350 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

July 8, 2019.
த໺‫ࢤو‬, ౦ୡ໵, Ӌ৔޺ޫ, ᴡ౻௚ਓ, দ‫ݪ‬༤ೋ, ʮઌಋతͳྔࢠϏʔϜԠ༻ʹΑΔεϚʔτͳ݈߁௕णࣾձͷ૑ग़ʯ, ಺ֳ෎ ୈ 2ճ೔ຊΦʔϓϯΠϊϕʔγϣϯେ৆೔ຊֶज़ձٞձ௕৆, 2020 ೥ 2 ݄ 15 ೔.

Press releasesࣗવքͰ࠷খͷྭ‫ى‬ΤωϧΪʔΛ΋ͭ‫֩ࢠݪ‬ঢ়ଶͷਓ޻తੜ੒ʹ੒ޭ—௒ਫ਼ີʮ‫ܭ࣌֩ࢠݪ‬ʯ࣮‫ʹݱ‬େ͖͘લਐ—, ཧԽֶ‫ڀݚ‬ॴ, 2019 ೥ 9 ݄ 11 ೔. https://www.riken.jp/press/2019/20190912_1/ .
τϦ΢Ϝ‫֩ࢠݪ‬ͷਫ਼ີϨʔβʔ෼ޫ࣮‫΁ݱ‬ॏཁͳҰา—τϦ΢Ϝ 229 ΞΠιϚʔঢ়ଶͷΤωϧΪʔΛܾఆ—, ཧԽֶ‫ॴڀݚ‬, 2019೥ 11 ݄ 29 ೔. https://www.riken.jp/press/2019/20191129_2/ .

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Accelerator Applications Research Division
RI Application Research Group
Industrial Application Research Team
1. Abstract

Industrial application research team handles non-academic activities at RIBF corresponding mainly to industries.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Support of industrial utilization of the RIBF accelerator beam.
Development of technologies related to the industrial utilization and novel industrial applications.
Fee-based distribution of radioisotopes produced at RIKEN AVF Cyclotron.
Development of real-time wear diagnostics of industrial material using RI beams.

3. Summary of Research Activity(1) Support of Industrial Utilization of RIBF
RNC promote facility-sharing program “Promotion of applications of high-energy heavy ions and RI beams.” In this program,
RNC opens a part of the RIBF facility, which includes the AVF cyclotron, RILAC, RIKEN Ring Cyclotron and experimental instruments, to non-academic proposals from users including private companies. The proposals are reviewed by a program advisorycommittee, industrial PAC (IN-PAC). The proposals which have been approved by the IN-PAC are allocated with beam times and theusers pay RIKEN the beam time fee. The intellectual properties obtained by the use of RIBF belong to the users. In order to encourage
the use of RIBF by those who are not familiar with utilization of ion beams, the first two beam times of each proposal can be assigned
to trial uses which are free of beam time fee.
In July 2019, the ninth IN-PAC met and approved two fee-based proposals from new users. In January 2019, IN-PAC held amail review and approved one fee-based proposal from a continuously using private company. In January and February 2019, fourfee-based beam times were performed with Kr-84 (70 MeV/nucleon) and Ar-40 (95 MeV/nucleon) beams at the E5A beamline. The
client used the beam to simulate single-event eﬀects of space-use semi-conductors by heavy-ion components of cosmic rays.
(2) Development of technologies related to the industrial utilization and novel industrial applications
We develop technologies to assess and improve the beam quality. Before each beam time, we measure the properties of the beam;
the dependence of the beam energy on the degrader thickness, the beam LET-distribution at a certain depth of an irradiated sample
calculated with the energy-loss code (SRIM), and the relation between the beam flux and the reading of a transmission-type detectors.
Since the beam is extracted to the atmosphere and passes through materials, it can be contaminated with secondary nuclides producedby nuclear reactions in the materials. We study the beam impurity using radiochemical measurements and compared the results withsimulations by the PHITS code. We tested radiochromic films as a new method of two-dimensional dose distribution measurement.
We have irradiated two types of radiochromic films using C, Ar, and Fe ions and measured the change of optical density as a functionof the dose. We conclude that radiochromic films can be useful to measure the dose distribution of heavy-ion irradiations with a spatial
resolution of about 1 mm.
(3) Fee-based distribution of radioisotopes produced at RIKEN AVF Cyclotron
We have been handling fee-based distribution of radioisotopes since 2007. The radionuclides are Zn-65 (T 1/2 = 244 days), Cd-109(463 days), Y-88 (107 days), Sr-85 (65 days) and Cu-67 (2.58 days) which are produced at the AVF cyclotron by the nuclear chemistryresearch team. According to a material transfer agreement (MTA) drawn between Japan Radioisotope Association (JRIA) and RIKEN,
JRIA mediates the transaction of the RIs and distributes them to users. Details can be found on the online ordering system J-RAM
home page of JRIA.
In 2019, we delivered no Cd-109, two shipments of Zn-65 with a total activity of 6.7 MBq, two of Y-88 with a total activity of
2 MBq, and one of Cu-67 with an activity of 5 MBq. The final recipients of the RIs were two universities, one research institute andone medical research center.
(4) Development of real-time wear diagnostics of industrial material using RI beams
We are developing a method to determine the spatial distribution of gamma-ray emitting RIs on periodically-moving objects,
named “GIRO” (Gamma-ray Inspection of Rotating Object), that is based on the same principle as the medical PET imaging but issimpler and less expensive. Two pairs of detectors were employed to obtain 3D image data. We also performed single-photon emission
computer tomography (SPECT) mode measurement. GIRO can obtain SPECT-mode data together with PET-mode data. This method
can be used for real-time inspection of a closed system in a running machine. In 2019, we are developing a portable size GIRO system
in order to bring and demonstrate it for private companies.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Members
Team Leader
Atsushi YOSHIDA
Contract Researcher
Tadashi KAMBARA
Technical Staﬀ I
Daiki MORI

List of Publications & Presentations
Presentations[Domestic conferences/workshops]٢ాರ (‫ޱ‬಄ൃදʣ, ʮՃ଎‫ࢪث‬ઃͰൃੜ͢ΔΠΦϯϏʔϜͷඇੜ෺‫ۀ࢈ܥ‬ར༻ʯ, ෱ҪΠΦϯϏʔϜҭछ‫ڀݚ‬ձ, ෱Ҫ‫ݝ‬ए‫ڱ‬࿷ΤωϧΪʔ‫ڀݚ‬ηϯλʔ, ರլ, 2019 ೥ 12 ݄ 13 ೔.
٢ాರ (‫ޱ‬಄ൃදʣ, ʮӉ஦࣌୅౸དྷʙ൒ಋମͰ΋ॏΠΦϯরࣹʙʯ, ཧ‫ݚ‬γϯϙδ΢ϜʮॏΠΦϯϏʔϜҭछٕज़ͷ࣮༻Խ 20 ೥ʯ,
࿨ޫ, 2020 ೥ 1 ݄ 23 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
Quantum Hadron Physics Laboratory
1. Abstract

Atomic nuclei are made of protons and neutrons bound by the exchange of pion and other mesons. Also, protons and neutrons
are made of quarks bound by the exchange of gluons. These strong interactions are governed by the non-Abelian gauge theory
called the quantum chromodynamics (QCD). On the basis of theoretical and numerical analyses of QCD, we study the interactions
between the nucleons, properties of the dense quark matter realized at the center of neutron stars, and properties of the hot quark-gluon
plasma realized in the early Universe. Strong correlations common in QCD and cold atoms are also studied theoretically to unravel
the universal features of the strongly interacting many-body systems. Developing perturbative and non-perturbative techniques inquantum field theory and string theory are of great importance not only to solve gauge theories such as QED and QCD, but also to findthe theories beyond the standard model of elementary particles. Various theoretical approaches along this line have been attempted.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Perturbative and non-perturbative methods in quantum field theories
Theory of spontaneous symmetry breaking
Lattice gauge theory
QCD under extreme conditions
Nuclear and atomic many-body problems

3. Summary of Research Activity(1) Perturbative and non-perturbative methods in quantum field theories(1-1) Theory of the Anomalous Magnetic Moment of the Electron
The anomalous magnetic moment of the electron ae measured in a Penning trap occupies a unique position among high precision
measurements of physical constants in the sense that it can be compared directly with the theoretical calculation based on the renormalized quantum electrodynamics (QED) to high orders of perturbation expansion in the fine structure constant α, with an eﬀective
parameter α/π. Both numerical and analytic evaluations of ae up to (α/π)4 were firmly established. The coeﬃcient of (α/π)5 has
been obtained recently by an extensive numerical integration. The contributions of hadronic and weak interactions have also been
estimated. The sum of all these terms leads to ae (theory) = 1 159 652 181.606 (11)(12)(229) × 10−12 , where the first two uncertainties
are from the tenth-order QED term and the hadronic term, respectively. The third and largest uncertainty comes from the current bestvalue of the fine-structure constant derived from the cesium recoil measurement: α−1 (Cs) = 137.035 999 046 (27). The discrepancy
between ae (theory) and ae ((experiment)) is 2.4σ. Assuming that the standard model is valid so that ae (theory) = ae (experiment) holds,
we obtained α−1 (ae ) = 137.035 999 1496 (13)(14)(330), which is nearly as accurate as α−1 (Cs). The uncertainties are from thetenth-order QED term, hadronic term, and the best measurement of ae , in this order.
(1-2) Optimized perturbation theory and its relation to anti-Stokes lines
We discussed fundamental properties of the fastest apparent convergence (FAC) condition which is used as a variational criterion
in optimized perturbation theory (OPT). We examine an integral representation of the FAC condition and a distribution of the zerosof the integral in a complex artificial parameter space on the basis of theory of Lefschetz thimbles. We find that the zeros accumulate
on a certain line segment known as an anti-Stokes line in the limit K → ∞, where K is a truncation order of a perturbation series.
This phenomenon gives an underlying mechanism that physical quantities calculated by OPT can be insensitive to the choice of theartificial parameter.
(1-3) Perturbative static quark potential in Maximal Abelian gauge
One of the most interesting features of QCD is its peculiar behavior at low energies, where it displays confinement. Among themany explanations proposed for this phenomenon, one of the more interesting approaches utilizes its similarity to the behavior of amagnetic field in a type II superconductor. The magnetic field cannot penetrate the superconductor except for narrow flux tubes, much
like the chromoelectric field extends only between confined particles, and if there existed elementary magnetic charges, they would
be confined inside a superconductor much like quarks in the vacuum. We calculated the static quark potential for an SU(N) gauge
theory in the Maximal Abelian gauge as well as its Abelian projection up to two loops in perturbation theory, and we discussed its
renormalization properties.
(1-4) Lorentzian conformal field theories through sine-square deformation
In quantum field theories, symmetry plays an essential and exceptional role. Focusing on some proper symmetry and delving
into its meaning have been proven to be one of the most fruitful strategies. We reexamined two-dimensional Lorentzian conformal
field theory using the formalism previously developed in a study of sine-square deformation of Euclidean conformal field theory. We
construct three types of Virasoro algebra. One of them reproduces the result by Lüscher and Mack, while another type exhibits thedivergence in the central charge term. The other leads the continuous spectrum and contains no closed time-like curve in the system.
(2) Theory of spontaneous symmetry breaking(2-1) Eﬀective Lagrangian for Nambu-Goldstone modes in nonequilibrium open systems
We developed the eﬀective field theory of diﬀusive Nambu-Goldstone (NG) modes associated with spontaneous internal symmetry
breaking taking place in nonequilibrium open systems. The eﬀective Lagrangian describing semi-classical dynamics of the NG modes- 354 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

is derived and matching conditions for low-energy coeﬃcients are also investigated. Due to new terms peculiar to open systems, theassociated NG modes show diﬀusive gapless behaviors in contrast to the propagating NG mode in closed systems. We demonstrate
two typical situations relevant to the condensed matter physics and high-energy physics, where diﬀusive type-A or type-B NG modes
appear.
(2-2) Spontaneous symmetry breaking and Nambu-Goldstone modes in open classical and quantum systems
Spontaneous symmetry breaking (SSB) in Hamiltonian systems is a universal and widely observed phenomena in nature, e.g.,
the electroweak and chiral symmetry breakings, superconductors, ferromagnets, solid crystals, and so on. It is also known that the
SSB occurs even in dissipative systems such as reaction diﬀusion system and active matters. We discussed spontaneous symmetry
breaking of open classical and quantum systems. When a continuous symmetry is spontaneously broken in an open system, a gaplessexcitation mode appears corresponding to the Nambu-Goldstone mode. Unlike isolated systems, the gapless mode is not always apropagation mode, but it is a diﬀusion one. Using the Ward-Takahashi identity and the eﬀective action formalism, we establish the
Nambu-Goldstone theorem in open systems, and derive the low-energy coeﬃcients that determine the dispersion relation of NambuGoldstone modes. Using these coeﬃcients, we classify the Nambu-Goldstone modes into four types: type-A propagation, type-A
diﬀusion, type-B propagation, and type-B diﬀusion modes.
(3) Lattice gauge theory(3-1) NΩ dibaryon from lattice QCD near the physical point
The nucleon(N)-Omega(Ω) system in the S-wave and spin-2 channel was studied from the (2+1)-flavor lattice QCD with nearly
physical quark masses. The time-dependent HAL QCD method is employed to convert the lattice QCD data of the two-baryon
correlation function to the baryon-baryon potential and eventually to the scattering observables. The potential, obtained under theassumption that its couplings to the D-wave octet-baryon pairs are small, is found to be attractive in all distances and to produce aquasi-bound state near unitarity. Including the extra Coulomb attraction, the binding energy of becomes 2.5 MeV. Such a spin-2 state
could be searched through two-particle correlations in p-p, p-nucleus and nucleus-nucleus collisions.
(3-2) ΛΛ and NΞ interactions from lattice QCD near the physical point
The S-wave ΛΛ and NΞ interactions were studied on the basis of the (2+1)-flavor lattice QCD simulations close to the physicalpoint. Lattice QCD potentials in four diﬀerent spin-isospin channels are extracted by using the coupled-channel HAL QCD method
and are parametrized by analytic functions to calculate the scattering phase shifts. The ΛΛ interaction at low energies shows only aweak attraction, which does not provide a bound or resonant dihyperon. The NΞ interaction in the spin-singlet and isospin-singlet
channel is most attractive and lead the NΞ system near unitarity. Relevance to the strangeness = −2 hypernuclei as well as to twobaryon correlations in proton-proton, proton-nucleus and nucleus-nucleus collisions was also discussed.
(3-3) Stress tensor around static quark-anti-quark from Yang-Mills gradient flow
The spatial distribution of the stress tensor around the quark-anti-quark pair in SU(3) lattice gauge theory was studied. The YangMills gradient flow plays a crucial role to make the stress tensor well-defined and derivable from the numerical simulations on thelattice. The resultant stress tensor with a decomposition into local principal axes shows, for the first time, the detailed structure of theflux tube along the longitudinal and transverse directions in a gauge invariant manner. The linear confining behavior of the potential
at long distances is derived directly from the integral of the local stress tensor.
(4) QCD under extreme conditions(4-1) Finite density QCD based on complex Langevin method
The complex Langevin method (CLM) is one of a promising approach to overcome the sign problem. The central idea of thisapproach is that the stochastic quantization does not require the probabilistic interpretation of the Boltzmann weight e−S even when theaction takes complex values. Although the equivalence between CLM and the familiar path integral quantization is quite nontrivial, it
is pointed out that the probability distribution of the drift term can judge the correctness of the CLM. This enable us to perform latticesimulation of QCD based on CLM in the finite density region in a self-contained manner. We discussed the applicability of the CLM
with four-flavor staggered fermions on a 83 × 16 lattice with quark mass m = 0.01. In particular, we focus on the behavior of theeigenvalue distribution of the fermion mass matrix which is closely related to the appearance of the singular drift problem.
(4-2) Non-equilibrium quantum transport of chiral fluids from kinetic theory
We introduced the quantum-field-theory (QFT) derivation of chiral kinetic theory (CKT) from the Wigner-function approach,which manifests side jumps and non-scalar distribution functions associated with Lorentz covariance and incorporates both backgroundfields and collisions. The formalism is utilized to investigate second-order responses of chiral fluids near local equilibrium. Such nonequilibrium anomalous transport is dissipative and aﬀected by interactions. Contributions from both quantum corrections in anomaloushydrodynamic equations (EOM) of motion and those from the CKT and Wigner functions (WF) are considered in a relaxation-time
approximation (RTA). Anomalous charged Hall currents engendered by background electric fields and temperature/chemical-potential
gradients are obtained. Furthermore, chiral magnetic/vortical eﬀects (CME/CVE) receive viscous corrections as non-equilibrium
modifications stemming from the interplay between side jumps, magnetic-moment coupling, and chiral anomaly.
(4-3) Hadron-quark crossover in cold and hot neutron stars
We presented a much improved equation of state for neutron star matter, QHC19, with a smooth crossover from the hadronic
regime at lower densities to the quark regime at higher densities. We now use the Togashi et al. equation of state, a generalization of
the Akmal-Pandharipande-Ravenhall equation of state of uniform nuclear matter, in the entire hadronic regime; the Togashi equation ofstate consistently describes nonuniform as well as uniform matter, and matter at beta equilibrium without the need for an interpolation
between pure neutron and symmetric nuclear matter. We describe the quark matter regime at higher densities with the Nambu-Jona-- 355 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Lasinio model, now identifying tight constraints on the phenomenological universal vector repulsion between quarks and the pairing
interaction between quarks arising from the requirements of thermodynamic stability and causal propagation of sound. The resultant
neutron star properties agree very well with the inferences of the LIGO/Virgo collaboration, from GW170817, of the pressure versus
baryon density, neutron star radii, and tidal deformabilities. The maximum neutron star mass allowed by QHC19 is 2.35 MS, consistent
with all neutron star mass determinations.
(5) Nuclear and atomic many-body problems(5-1) Renormalized random-phase approximation
A fully self-consistent renormalized random-phase approximation was constructed based on the self-consistent Hartree-Fockmean field plus exact pairing solutions (EP). This approach exactly conserves the particle number and restores the energy-weighted
sum rule, which is violated in the conventional renormalized particle-hole random-phase approximation for a given multipolarity. The
numerical calculations are carried out for several light-, medium-, and heavy-mass nuclei such as O22, Ni60, and Zr90 by using theeﬀective MSk3 interaction. To study the pygmy dipole resonance (PDR), the calculations are also performed for the two light andneutron-rich O24,28 isotopes, whose PDRs are known to be dominant. The results obtained show that the inclusion of ground-statecorrelations beyond the random-phase approximation (RPA) by means of the occupation numbers obtained from the EP aﬀects the
RPA solutions within the whole mass range, although this eﬀect decreases with increasing the mass number. At the same time, theantipairing eﬀect is observed via a significant reduction of pairing in neutron-rich nuclei. The enhancement of PDR is found in mostneutron-rich nuclei under consideration within our method.
(5-2) Ab initio covariant density functional theory for nuclear structure
Nuclear structure models built from phenomenological mean fields, the eﬀective nucleon-nucleon interactions (or Lagrangians),
and the realistic bare nucleon-nucleon interactions were presented. The success of covariant density functional theory (CDFT) to
describe nuclear properties and its influence on Brueckner theory within the relativistic framework are focused upon. The challenges
and ambiguities of predictions for unstable nuclei without data or for high-density nuclear matter, arising from relativistic density
functionals, are discussed. The basic ideas in building an ab initio relativistic density functional for nuclear structure from ab initio
calculations with realistic nucleon-nucleon interactions for both nuclear matter and finite nuclei are presented. The current statusof fully self-consistent relativistic Brueckner-Hartree-Fock (RBHF) calculations for finite nuclei or neutron drops (ideal systems
composed of a finite number of neutrons and confined within an external field) is reviewed. The guidance and perspectives towards an
ab initio covariant density functional theory for nuclear structure derived from the RBHF results are provided.
(5-3) QCD-like phase diagram with Efimov trimers and Cooper pairs
We investigated color superfluidity and trimer formation in resonantly interacting SU(3) Fermi gases with a finite interaction
range. The finite range is crucial to avoid the Thomas collapse and treat the Efimov eﬀect occurring in this system. Using theSkorniakov-Ter-Martirosian equation with medium eﬀects, we show the eﬀects of the atomic Fermi distribution on the Efimov trimer
energy at finite temperature. We show the critical temperature of color superfluidity within the many-body T-matrix approximation.
In this way, we can provide a first insight into the phase diagram as a function of the temperature T and the chemical potential µ.
This phase diagram consists of trimer, normal, and color-superfluid phases, and is similar to that of quantum chromodynamics at finite
density and temperature.
(5-4) Superfluid phase transitions in asymmetric nuclear matter
We investigated superfluid phase transitions of asymmetric nuclear matter at finite temperature (T) and density (ρ) with a low
proton fraction (Y p ≤ 0.2), which is relevant to the inner crust and outer core of neutron stars. A strong-coupling theory developed
for two-component atomic Fermi gases is generalized to the four-component case, and is applied to the system of spin-1/2 neutronsand protons. The phase shifts of neutron-neutron (nn), proton-proton (pp) and neutron-proton (np) interactions up to k = 2 fm−1 areCof the neutron superfluidity at Y p = 0 agrees
described by multi-rank separable potentials. We show that the critical temperature T nn
Cwell with Monte Carlo data at low densities and takes a maximum value T nn = 1.68 MeV at ρ/ρ0 = 0.14 with ρ0 = 0.17 fm−3 . Also,Cof the proton superconductivity for Y p ≤ 0.2 is substantially suppressed at low densities due to np-pairing
the critical temperature T nn
C
only above ρ/ρ0 = 0.70(0.77) for Y p = 0.1(0.2), and (iii) the deuteron condensation
fluctuations, and starts to dominate over T nn
temperature T dC is suppressed at Y p ≤ 0.2 due to a large mismatch of the two Fermi surfaces.
(5-5) One-dimensional Bose and Fermi gases with contact interactions
One-dimensional spinless Bose and Fermi gases with contact interactions have the close relationship via Girardeau’s Bose-Fermi
mapping, leading to the correspondences in their energy spectra and thermodynamics. However, correlation functions are in general
not identical between these systems. We derive in both systems the universal relations for correlation functions, which hold for any
energy eigenstate and any statistical ensemble of the eigenstates. These relations include the large-momentum tails of static structure
factors and of momentum distributions as well as energy relations, which connect the sums of kinetic and interaction energies to themomentum distributions. The relations involve two- and three-body contacts, which measure local two- and three-body correlations,
respectively. We clarified how the relations for bosons and fermions diﬀer and are connected with each other. In particular, we foundthat the three-body contact makes no contribution to the bosonic energy relation, but it plays a crucial role in fermionic one.

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Members
Director
Tetsuo HATSUDA
Vice Chief Scientist
Tsukasa TADA
Research/Technical Scientists
Takumi DOI (Senior Research Scientist)
Yoshimasa HIDAKA (Senior Research Scientist)

Pascal Raphaël Gabriel NAIDON (Senior Research Scientist)
Haozhao LIANG (Senior Research Scientist)

Senior Scientist
Makiko NIO
Contract Researcher
Dang NGUYEN DINH
Special Postdoctoral Researchers
Tomoya HAYATA
Matthias W.G. BERWEIN
Takahiro DOI
Shinya GONGYO

Kazuya MAMEDA
Enrico RINALDI
Shoichiro TSUTSUI

Postdoctoral Researcher
Christiane Heike SCHMICKLER
Research Consultant
Takeo INAMI (Sungkyunkwan Univ. (SKKU))
Visiting Scientists
Shinya AOKI (Kyoto Univ.)
Tatsumi AOYAMA (KEK)
Gergely P. FEJOS (Eotvos Lorand Univ.)
Kenji FUKUSHIMA (Univ. of Tokyo)
Hideki HAMAGAKI (Nagasaki Inst. of Applied Sci.)
Koji HASHIMOTO (Osaka Univ.)
Masashi HAYAKAWA (Nagoya Univ.)
Tomoya HAYATA (Keio Univ.)
Yoichi IKEDA (Kyushu Univ.)
Takashi INOUE (Nihon Univ.)
Noriyoshi ISHII (Osaka Univ.)
Yoichi KAZAMA (Univ. of Tokyo)
Ivan KOSTOV (Inst. de Phys. Theorique)Tetsuo MATSUI (The Open Univ. of Japan)
Takayuki MATSUKI (Tokyo Kasei Univ.)
Takaya MIYAMOTO (NEC Corporation)
Kenji MORITA (QST)

Masaki MURATA (Japan Univ. Economics)
Atsushi NAKAMURA (Hiroshima Univ.)
Takashi NAKATSUKASA (Tsukuba Univ.)
Hung NGUYEN (Duy Tan Univ.)
Yoji OHASHI (Keio Univ.)
RHINE KUMAR ARAYAKKANDI KEECH (Cochin Univ. ofSci. and Tech.)
Norisuke SAKAI (Keio Univ.)
Kenji SASAKI (Kyoto Univ.)
Shoichi SASAKI (Tohoku Univ.)
Hiroshi SUZUKI (Kyushu Univ.)
Motoi TACHIBANA (Saga Univ.)
Sachiko TAKEUCHI (Japan College of Social Work)
Makoto TAKIZAWA (Showa Pharmaceutical Univ.)
Hiroshi TOKI (Osaka Univ.)
Di-Lun YANG (Keio Univ.)

Visiting Researchers
Yuta SEKINO (JSPS)

Hiroyuki TAJIMA (Kochi Univ.)

Student Trainees
Yutaro AKAHOSHI (Kyoto Univ.)
Asahi CHIKAOKA (Univ. of Tokyo)
Yixin GUO (Univ. of Tokyo)
Xun LIU (Univ. of Tokyo)
Yan LYU (Peking Univ.)
Kotaro MURAKAMI (Kyoto Univ.)

Tomoya NAITO (Univ. of Tokyo)
Hikaru SAKAKIBARA (Univ. of Tokyo)
Ziting SUN (Univ. of Sci. and Tech. of China)
Hui TONG (Peking Univ.)
Zhenyu WANG (Nankai Univ.)
Tingyu ZHANG (Univ. of Sci. and Tech. of China)- 357 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
Strangeness Nuclear Physics Laboratory
1. Abstract

We proposed accurate calculation method called ‘Gaussian Expansion Method using infinitesimally shifted Gaussian lobe basis
function.’ When one proceeds to four-body systems, calculation of the Hamiltonian matrix elements becomes much laborious. In orderto make the four-body calculation tractable even for complicated interactions, the infinitesimally-shifted Gaussian lobe basis function
has been proposed. The GEM with the technique of infinitesimally-shifted Gaussians has been applied to various three-, four- andfive-body calculations in hypernuclei, the four-nucleon systems, and cold-atom systems. As results, we succeeded in extracting newunderstandings in various fields.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Hypernuclear structure from the view point of few-body problem
Structure of exotic hadron system
quantum atomic system and ultra cold atomic system
Equation of state for neutron star

3. Summary of Research Activity(1) With use of ΞN interaction based on HAL Lattice QCD, we predict to have a bound state for NN Ξ four-body system which
would be the lightest bound Ξ hypernucleus. We also propose how to produce this hypernucleus.
(2) Several compact ssscc-bar pentaquark resonances are predicted quark model, that is, J π = 1/2− ‘E = 5180 MeV, Γ =20 MeV), 5/2− (5645 MeV, 30 MeV), 5/2− (5670 MeV, 50 MeV), and 1/2+ (5360 MeV, 80 MeV). These are the candidatesof compact pentaquark resonance states from the current best quark model, which should be confirmed either by experiments
or lattice QCD calculations.
(3) Mixtures of two kinds of fermions, such as spin up and down electrons in materials, are well-known to lead to pairing andsuperconductivity. In this project, study mixtures of three diﬀerent kinds of fermions were studied. In these systems, inaddition to pairing, a new kind of clustering by three can appear due the Efimov eﬀect. We obtained the phase diagram ofthese systems and showed that it is similar to that of QCD, where the hadron phase is the analogue of the phase of Efimovclusters of three fermions.

Members
Director
Emiko HIYAMA
Research/Technical Scientists
Pascal NAIDON (Senior Research Scientist)
Special Postdoctoral Researcher /Contract Researcher
Yasuhiro YAMAGUCHISpecial Postdoctoral Researcher
Kadir Utku CAN Takuma YAMASHITA
Postdoctoral Researcher
Christiane H. SCHMICKLER
Senior Visiting Scientist
Makoto OKA (JAEA)
Visiting Scientists
Masayuki ASAKAWA (Osaka Univ.)
Kadir Utku CAN (The Univ. of Adelaide)
Jaume CARBONELL (CNRS/IN2P3, IJCLab)
Lorenzo CONTESSI (Hebrew Univ. of Jerusalem)
Jiwei CUI (Xidian Univ.)
Akinobu DOTE (KEK)
Shimpei ENDO (Tohoku Univ.)
Tomokazu FUKUDA (Univ. of Electro-Commun.)
Yasuro FUNAKI (Kanto Gakuin Univ.)
Takenori FURUMOTO (Yokohama Nat’l Univ.)
Philipp GUBLER (JAEA)

Satoru HIRENZAKI (Nara Women’s Univ.)
Atsushi HOSAKA (Osaka Univ.)
Jinniu HU (Nankai Univ.)
Tetsuo HYODO (Tokyo Metropolitan Univ.)
Kiyomi IKEDA (Niigata Univ.)
Masahiro ISAKA (Hosei Univ.)
Souichi ISHIKAWA (Hosei Univ.)
Daisuke JIDO (Tokyo Tech)
Hyun-Chul KIM (Inha Univ.)
Kei KOTAKE (Fukuoka Univ.)
Toshio MOTOBA (Univ. of Electro-Commun.)- 358 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Takayuki MYO (Osaka Inst. of Tech.)
Satoshi NAKAMURA (Tohoku Univ.)
Kazuma NAKAZAWA (Gifu Univ.)
Hidekatsu NEMURA (Osaka Univ.)
Jean-Marc RICHARD (Univ. Lyon)
Thomas RIJKEN (Univ. Of Nijmegen)Hans-Josef SCHULZE (INFN)
Shoji SHINMURA (Gifu Univ.)
Jirina STONE (Univ. of Tennessee)
Hajime TOGASHI (Kyushu Univ.)
Atsushi UMEYA (Nippon Inst. of Tech.)

Shin WATANABE (NIT, Gifu College)
Wolfram WEISE (TU Munich)Chengjun XIA (Zhejiang Univ.)
Masanobu YAHIRO (Kyushu Univ.)
Ulugbek YAKHSHIEV (Inha Univ.)
Taiichi YAMADA (Kanto Gakuin Univ.)
Yasuo YAMAMOTO (Tsuru Univ.)
Takuma YAMASHITA (Tohoku Univ.)
Ying ZHANG (Tianjin Univ.)
Xian-Rong ZHOU (East China Normal Univ.)

Student Trainees
Kongyi HU (Nankai Univ.)
Jehee LEE (Tokyo Tech)
Jie LIU (Nanjing Univ.)

Qi MENG (Nanjing Univ.)
Qian WU (Nanjing Univ.)

Part-time Worker
Yoko FUJITA (Administrative Part-time Worker I)

List of Publications & Presentations
Publications[Original papers]
J. Lee, Q. Wu, Y. Funaki, and E. Hiyama, “Three-Body structure of Λ9 Be with ααΛ cluster model,” Few-Body Syst. 60, 30 (2019).
R. Lazauskas, E. Hiyama, and J. Carbonell, “Ab initio calculation of 5 H resonant states,” Phys. Lett. B 791, 335 (2019).
J. Lee, N. Yamanaka, and E. Hiyama, “Eﬀect of the Pauli exclusion principle in the electric dipole moment of 9 Be with |∆S | = 1
interactions,” Phys. Rev. C 99, 055503 (2019).
E. Hiyama, R. Lazauskas, F. M. Marques, and J. Carbonell, “Modeling 19 B as a 17 B-n-n three-body system in the unitary limit,” Phys.
Rev. C 100, 011603(R) (2019).
T. -W. Wu, M. -Z. Liu, L. -S. Geng, E. Hiyama, and M. P. Valderrama, “DK, DDK and DDDK molecules-understanding the nature of theD∗s0 (2317),” Phys. Rev. D 100, 034209 (2019).
E. Hiyama, K. Sasaki, T. Miyamaoto, T. Doi, T. Hatsuda, Y. Yamamoto, and T. Rijken, “Possible lightes Ξ hypernuceus with Modern ΞNinteraction,” Phys. Rev. Lett. 124, 092501 (2020).
Y. Shimizu, Y. Yamaguchi, and M. Harada, “Heavy quark spin multiplet structure of Pc(4312), Pc(4440), and Pc(4457),”
arXiv:1904.00587 [hep-ph] (2019).
Y. Yamaguchi, H. G.- Tecocoatzi, A. Giachino, A. Hosaka, E. Santopinto, S. Takeuchi, and M. Takizawa, “Pc pentaquarks with chiraltensor and quark dynamics,” Phys. Rev. D 101, 091502 (2020).
Y. Yamaguchi and N. Yamanaka, “Large electric dipole moment of charged leptons in the standard model,” arXiv:2003.08195 [hep-ph](2020).
Q. Meng, E. Hiyama, K. U. Can, P. Gubler, M. Oka, A. Hosaka, and H. Zong, “Compact ssscc pentaquark states predicted by a quark
model,” Phys. Lett. B 798, 135028 (2019).
P. Froelich, T. Yamashita, Y. Kino, S. Jonsell, E. Hiyama, and K. Piszczatowski, “Four-body treatment of the antihydrogen-positronium
system: binding, structure, resonant states and collisions,” Hyperfine Interact. 240, 46 (2019).

[Review articles]
Y. Yamaguchi, A. Hosaka, S. Takeuchi, and M. Takizawa, “Heavy hadronic molecules with pion exchange and quark core couplings: a
guide for practitioners,” J. Phys. G 47, 053001 (2020).

[Proceedings]
Y. Yamaguchi, “pi J/psi-DDbar* potential described by the quark exchange diagram,” EPJ Web Conf. 204, 01007 (2019).
Y. Yamaguchi, “Short range interaction in pi J/psi-DDbar* channel,” Int. J. Mod. Phys. Conf. Ser. 49, 1960005 (2019).
Y. Yamaguchi, “Short range pi J/psi -DDbar* potential described by the quark exchange diagram,” Springer Proc. Phys. 238, 629 (2020).

Presentations[International conferences/workshops]
E. Hiyama (invited), “Five-body structure of sssc c,” The 1st CENuM Workshop for Hadron Physics, Incheon, Korea, June 17–18, 2019.
E. Hiyama (invited), “Structure of light Ξhypernuclei with modern ΞN interaction,” International workshop on “Nuclear structure at thecrossroads” (INT 19-2a), Seattle, U.S.A., July 1–August 2, 2019.
E. Hiyama (invited), “Five-body structure of sssc c,” International Workshop on Perspectives in Hadron Physics, Quy Nhon, Vietnam,
September 22–28, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

P. Naidon (Invited), “A bubble of polarons,” 2nd workshop “Clusters in quantum systems: from atoms to nuclei and hadrons,” Fukuoka,
Japan, January 27–31, 2020.
Y. Yamaguchi (oral), “Role of the tensor force in the heavy hadronic molecules,” The 18th International Conference on Hadron Spectroscopy and Structure (HADRON2019), Guilin, China, August 16–21, 2019.
Y. Yamaguchi (oral), “Tensor force in heavy hadronic molecules,” Workshop on Chiral and heavy quark symmetries in quark-hadron
physics, Osaka, Japan, August 25, 2019.
Y. Yamaguchi (oral), “Hadronic molecules of heavy hadrons with tensor force,” The 24th European conference on few-body problems inphysics (EFB24), Guirford, UK, September 2–6, 2019.
Y. Yamaguchi (oral), “Heavy hadronic molecules: pion exchange and coupling to multiquark states,” Workshop on “Physics of heavyquark and exotic hadrons,” Tokai, Ibaraki, Japan, January 27–29, 2020.
Y. Yamaguchi (oral/poster), “Tensor force in the heavy hadronic molecules,” REIMEI Workshop on Universal Features of Quantum Flows
with Spin, Orbital and Tensor Correlations, Tokai, Ibaraki, Japan, February 17–19, 2020.
K. U. Can (oral), “Structure of the charmed baryons through an electromagnetic perspective,” 15th Rencontres du Vietnam Perspectives
in Hadron Physics, ICISE, Quy Nhon, Vietnam, September 22–28, 2019.
T. Yamashita, Y. Kino, E. Hiyama, S. Jonsell, and P. Froelich (poster), “Inelastic resonant scattering of positronium by (anti)hydrogenatom,” XX International Workshop on Low-Energy Positron and Positronium Physics & XXI International Symposium on ElectronMolecule Collisions and Swarms, Belgrade, Serbia, July 18–20, 2019.
T. Yamashita, Y. Kino, E. Hiyama, K. Piszczatowski, S. Jonsell, and P. Froelich (oral, hot topic), “Towards prediction of the rates ofantihydrogen positive ion production in antihydrogen-excited positronium reaction,” XXXIst International Conference on Photonic,
Electronic, and Atomic Collisions (ICPEAC), Deauville, France, July 23–30, 2019.
M. Niiyama, T. Yamashita, and Y. Kino (poster), “Four-body calculation of energy levels of muonic molecule dtµe in muon catalyzed
fusion,” XXXIst International Conference on Photonic, Electronic, and Atomic Collisions, Deauville, France, July 23–30, 2019.
T. Yamashita, M. Umair, Y. Kino, and E. Hiyama (poster), “Coupled rearrangement channel calculation of dipole resonance states of
positronic helium atom,” XXXIst International Conference on Photonic, Electronic, and Atomic Collisions, Deauville, France, July
23–30, 2019.
C. H. Schmickler (oral), “Universal few-body physics of charged particles,” REIMEI Workshop on “Universal features of quantum flows
with spin, orbital and tensor correlations,” Tokai, Ibaraki, Japan, February 17–19, 2020.

[Domestic conferences/workshops]ࢁ‫ޱ( ޺߁ޱ‬಄ൃද), ʮύΠΦϯަ‫ͱྗ׵‬ϋυϩϯ෼ࢠঢ়ଶʯ, ‫ڀݚ‬ձʮΫΥʔΫ໛‫͔ܕ‬ΒΈͨΤΩκνοΫϋυϩϯ‫ڀݚ‬ͷਐలͱ
QCD ͷ৽ల։ʯ, ࿨ޫ, 2019 ೥ 7 ݄ 6 ೔.
ࢁ‫ޱ( ޺߁ޱ‬಄ൃද), ʮ2 ϝιϯ‫͚͓ʹܥ‬ΔϔϏʔϑϨʔόʔަ‫׵‬૬‫༻࡞ޓ‬ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄
17–20 ೔.
ࢁ‫ޱ( ޺߁ޱ‬಄ൃද), ʮిࢠͷి‫ؾ‬૒‫ࢠۃ‬Ϟʔϝϯτʹ͓͚Δϋυϩϯϧʔϓͷ‫د‬༩ʯ, Flavor Physics Workshop 2019, ෋ాྛ, 2019೥ 11 ݄ 19–22 ೔.

[Seminars]
Y. Yamaguchi, “Heavy hadronic molecules: pion exchange and coupling to compact states,” Tokyo Institute of Technology, Tokyo,
December 13, 2019.
Y. Yamaguchi, “Heavy hadronic molecules: pion exchange and coupling to compact states,” Nagoya University, Nagoya, Aichi, Japan,
December 17, 2019.
T. Yamashita and Y. Kino (oral), “For analysis of fundamental muonic atom process: development of few-body calculation method andrelated topics on relativistic eﬀects of exotic atoms,” Seminar on fundamental theories for negative muon experiments at J-PARC and
its application to elemental analysis, Tokai, Ibaraki, Japan, April 18, 2019.

Awardsංࢁӵඒࢠ, Պֶٕज़෼໺ͷจ෦Պֶେਉදজ Պֶٕज़৆ʢ‫ڀݚ‬෦໳ʣʮྔࢠগ਺ଟମ‫ܥ‬ͷ‫ࢉܭີݫ‬ཧ࿦ͷཱ֬ͱͦͷԠ༻‫ڀݚ‬ʯ,2019 ೥ 4 ݄ 17 ೔.

Press releasesංࢁӵඒࢠࣨ௕, ౔Ҫୖ਎ઐ೚‫ڀݚ‬һ, ਺ཧ૑଄ϓϩάϥϜͷॳా఩உϓϩάϥϜσΟϨΫλʔΒͷࠃࡍ‫ڞ‬ಉ‫ڀݚ‬άϧʔϓ, ৽ͨͳϋΠύʔ‫֩ࢠݪ‬ʮάβΠɾςτϥόϦΦϯʯ—άβΠཻࢠͷৼΔ෣͍Λਫ਼ີ‫Ͱࢉܭ‬ղ͖໌͔͢—, 2020 ೥ 3 ݄ 5 ೔.

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Subnuclear System Research Division
Radiation Laboratory
1. Abstract

Nucleons, such as protons and neutrons, are a bound state of constituent quarks glued together with gluons. The detail structureof nucleons, however, is not well understood yet. Especially the mechanism to build up the spin of proton, which is 1/2, is a major
problem in physics of the strong force. The research goal of Radiation Laboratory is to solve this fundamental question using the world
first polarized-proton collider, realized at RHIC in Brookhaven National Laboratory (BNL) in USA. RHIC stands for Relativistic
Heavy Ion Collider, aiming also to create Quark Gluon Plasma, the state of Universe just after the Big Bang, and study its property.
RIKEN-BNL Research Center (RBRC) also directed by H. En’yo carries our core team at BNL for those exciting researches using thePHENIX detector and its upgraded sPHENIX detector in preparation. We have observed that the proton spin carried by gluons is finite
and indeed sizable. We also identified W bosons in the electron/positron decay channel and in the muon decay channel, with which we
showed how much anti-quarks carry the proton spin. Other than the activities at RHIC we are preparing and starting new experiments
at J-PARC and Fermilab to study the nature of hadron and preparing for the electron-ion collider (EIC). We are also performing
technical developments such as novel ion sources, fine-pitch silicon pixel detectors and high-performance trigger electronics.

2. Major Research Subjects(1) Spin physics with relativistic polarized-proton collisions at RHIC
(2) Study of nuclear matter at high temperature and/or at high density(3) Technical developments on radiation detectors and accelerators

3. Summary of Research Activity(1) Experimental study of spin structure of proton using RHIC polarized proton collider[See also RIKEN-BNL Research Center Experimental Group for the activities at BNL]
The previously published central neutral pion double spin asymmetries at the highest collision energies at RHIC of 510 GeV havebeen augmented with the publication of the complementary charged pion double spin asymmetries at the same collision energy. The
ordering of the three pion asymmetries allows a direct determination of the sign of the gluon polarization which has been found to benonzero. These results will be included in future global fits of all the existing experimental data in the world and will improve thesensitivity of quark and gluon spin contributions to the total spin of the nucleon. Additionally, the first double spin asymmetry resultsfor direct photons and jets are being prepared by PHENIX. Both are in principle cleaner probes since no fragmentation functions are
involved. The direct photon probe also restricts the initial, hard interaction to be predominantly between a quark and a gluon thus
further increasing the sensitivity to the gluon spin.
While orbital angular momentum cannot be directly accessed at RHIC, several transverse spin phenomena have been observed
which relate to orbital angular momentum and the three-dimensional structure of the nucleon. These phenomena by themselves havebecome a major field of research as the dynamics of the strong interaction. During the 2015 RHIC operation, collisions of transversely
polarized protons with Au and Al nuclei were provided for the first time. Two rather surprising results have been discovered here.
First, the single transverse spin asymmetries for J/Ψ particles which are found to be consistent with zero to even higher precisions,show distinctly nonzero asymmetries in proton-Au collisions at the lowest transverse momenta both if detected at slightly forward
or backward regions with respect to the polarized beam. Also charged hadron single spin asymmetries have been observed in all
three colliding systems. While a previously known nonzero forward asymmetry for positive hadrons was confirmed, a substantial
reduction of these asymmetries for p + Al and p + Au collisions was observed. Such a reduction was predicted by several theoreticalmodels describing the non-linear eﬀects of high gluon densities in nuclei suggested by the so-called color-glass-condensate. While
the kinematic region does not reach into the range where the color-glass-condensate is expected, this reduction in asymmetries has
been met with interest by the theory community. The results have now been published. When moving to more central rapidities, theleft-right asymmetries are known to be very small for neutral pions. Since then they have been confirmed to be small also for eta
mesons and, for the first time, also for direct photons. The direct photon asymmetries are again very important here as they are only
sensitive to the transverse spin eﬀects in the initial state and not the fragmentation. Both results are being prepared for publication.
In June of 2017, an electro-magnetic calorimeter was installed in the most forward area of the STAR experiment and took polarized
proton collision data for neutral particle production (neutron, photon, neutral pion). The cross-section measurement will give us new
inputs to develop high-energy particle-collision models which are essential to understand air-shower from ultra-high energy cosmic
rays. The asymmetry measurement will enable us to understand the hadron collision mechanism based on QCD. An unexpectedly
large neutral pion asymmetry has been found using this data that may connect to the large pion asymmetries at smaller rapidities andhigher transverse momenta. The results have been accepted for publication in PRL.
Some of us are participating in the Fermilab SeaQuest experiment as a pilot measurement of muon pairs from Drell-Yan processusing a 120-GeV unpolarized proton at Fermilab. After finishing unpolarized measurements in 2017 to study the quark spin-orbit
eﬀect, a new measurement with a polarized proton target will start in 2020 to study the sea-quark orbit eﬀect of the polarized protonin the target.
For many jet related measurements fragmentation functions are necessary to gain spin and or flavor sensitivity. Those are currently
extracted by some of us using the KEK-Belle data. In addition to using the fragmentation results with RHIC measurements, they will
also provide the basis for most of the key measurements to be performed at the electron-ion collider. In 2019, transverse momentum- 361 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

dependent cross sections of pions, kaons and protons were published as a function of fractional energy and event topology. These
measurements relate to essentially all transverse spin or momentum dependent measurements at RHIC, semi-inclusive DIS and theEIC.
As the Electron-Ion Collider is becoming a reality, many of us are participating in the various community eﬀorts to define thephysics goals of the EIC and how they inform on the choices of collisions energies, luminosities and detector components. While theaccelerator eﬀorts are naturally led by the two main Nuclear physics laboratories in the US, BNL and JLAB, a large EIC user groupof more than 1000 members from all around the world is working on making the EIC a reality. Within this group, we are participatingin various functions from the steering committee, the conference and talks committee to various physics or detector related topicalgroups.
(2) Experimental study of quark-gluon plasma using RHIC heavy ion collider[See also RIKEN-BNL Research Center Experimental Group for the activities at BNL]
We have completed several key measurements in the study of quark-gluon plasma at RHIC. As the top of them, we lead theanalysis of the first thermal photon measurement in heavy ion collisions. The measurement indicates that the initial temperaturereached in the central Au + Au collision at 200 GeV is about 350 MeV, far above the expected transition temperature T c ∼ 170 MeV,
from hadronic phase to quark-gluon plasma. This work was rewarded by Nishina Memorial Prize given to Y. Akiba in 2011. We alsomeasured direct photons in d + Au and direct photon flow strength ν2 and ν3 in Au + Au.
We lead measurement of heavy quark (charm and bottom) using VTX, a 4-layer silicon vertex tracker which we jointly constructedwith US DOE. The detector was installed in PHENIX in 2011. PHENIX recorded approximately 10 times more data of Au+Au
collisions in the 2014 run than the 2011 run. PHENIX recorded high statistics p + p and p + A data in 2015, and the doubled the Au+ Au in 2016. PHENIX concluded its data taking in the 2016 run.
The results of the 2011 run was published in Physical Review C (Phys. Rev. C 93, 034904 (2016)). This is the first publicationfrom VTX. The result showed that the electrons from bottom quark decay is suppressed for pT > 4 GeV/c, but the suppression factor issmaller than that of charm decay electrons for 3 < pT < 4 GeV/c. This is the first observation of bottom electron suppression in heavy
ion collisions, and the first result that shows the bottom and charm suppression is diﬀerent. The results of b→e and c→e measurementin the 2015 p + p run has been published in Physical Review D99, 092003 (2019). The centrality dependence of the suppression b→e
and c→e from the 2014 Au+Au data is in preparation.
PHENIX published measurements of flow strength in p + Au, d + Au, and 3 He+Au (Nature Physics 15, 214 (2019)). The results
provide strong evidence for formation of small droplet of quark gluon plasma in collisions of small systems at RHIC.
In Wako we are operating a cluster computer system (CCJ) specialized to analyze huge data sets taken with the PHENIX detector.
It consists of 28 nodes (18 old nodes and 10 new nodes) each of which has two CPUs and 10 sets of local disks for data repository(old node: quad-core CPU, 1TB disk, new node: six-core CPU, 2 TB disk). There are 264 CPU cores and 380 TB disks in total.
This configuration ensures the fastest disk I/O when each job is assigned to the node where the required data sets are stored. It is also
important that this scheme doesn’t require an expensive RAID system and network. Through this development we have established afast and cost-eﬀective solution in analyzing massive data.
The data of 0.9 Pbyte obtained by the PHENIX experiment is stored in a hierarchical storage system which is a part of HOKUSAI
BigWaterfall/SailingShip supercomputer systems operated by the Head Oﬃce for Information Systems and Cybersecurity. In addition,
we operate a dedicated server for the RHICf group and two servers for the J-PARC E16 group, to keep their dedicated compilationand library environments, and some data.
(3) Study of properties of mesons and exotic hadrons with domestic accelerators
Preparation of the experiment E16 at J-PARC Hadron experimental facility is underway with several Grant-in-Aids. This experiment aims to perform a systematic study of the spectral modification of low-mass vector mesons in nuclei to explore the physics ofchiral symmetry breaking and restoration in dense nuclear matter, namely, the mechanism proposed by Nambu to generate most of
hadron masses.
The Gas Electron Multiplier (GEM) technology is adopted for the two key detectors, GEM Tracker (GTR) and Hadron-blind
Cherenkov detector (HBD). To improve electron-identification performance, lead-glass calorimeters (LG) are used in combination
with HBD. We are in the production phase. The parts for six modules of GTR, four modules of HBD and six modules of LG are
assembled and installed in the spectrometer magnet at J-PARC. Read-out electronics and trigger logic modules are also installed andtested. We have been a member of the CERN-RD51 collaboration to acquire the read-out technology for GEM. The MoU for RD51
was extended for the period of 2019–2023.
Due to the budgetary limitation, we aim to install a part of detectors at the beginning of the experiment, eight modules of
GTR/HBD/LG out of 26 modules in the full installation. J-PARC PAC gave us a stage-2 approval on July 2017, to the commissioning run (Run 0), which will be performed when the beam line is completed. Although there is a significant delay from theoriginally planned date of March 2016, the construction of the beam line by KEK was completed finally in early 2020 to perform
this experiment. We performed the 1st half of commissioning run (Run0a) in June 2020 successfully, and the 2nd half is planned in
January 2021.
(4) Detector development for PHENIX experiment
The PHENIX experiment proposes substantial detector upgrades to go along the expected accelerator improvements, including
the future electron-ion collider “EIC”. The present PHENIX detector is repurposed to the sPHENIX (super PHENIX) detector whichreuses the Babar solenoid magnet at SLAC and is covered by the hadronic calorimeter which was not available in the previous RHIC

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experiments. The sPHENIX was approved for the Project Decision-2/3 (corresponds to DOE’s Critical Decision-2/3) in May 2019.
We RIKEN group have been developing the one of the tracking devices of sPHENIX detector, so called intermediate tracker (INTT)
since 2015. The INTT provides the best timing resolution among the sPHENIX tracking system, in conjunction with a time projection
chamber and a MAPS based vertex detectors. The R&D of INTT detector is almost in the last stage. The prototype detectors
demonstrated satisfactory performance in the eﬃciency and position resolutions as designed in the last two beam tests at the Fermilab
Test Beam Facility (FTBF) using 120 GeV proton beam in March 2018 and June 2019. The preparation for the production ladderassembly is ongoing both in Taiwan Silicon Detector Facility (TSiDF) and BNL.
We have been developing a plan to build a forward spectrometer to be added to the sPHENIX detector. With this addition, thefsPHENIX detector will have both hadronic and electromagnetic calorimetry as well as tracking in the forward rapidity region. This
upgrade makes it possible to study forward jets and hadrons in jets which are of vital importance for the cold QCD program inpolarized p + p and p + A collisions at RHIC. The fsPHENIX detector can be further upgraded to the ePHENIX detector to be used
for electron-ion collisions at EIC. We are preparing test bench to perform R&D for the forward hadron calorimeter.
As the further investigation of the neutral pion production asymmetry discovered in the RHICf experiment, we started preparation
for the next phase of the experiment, namely RHICf-II. The target year of physics data taking is 2024 as a part of sPHENIX experiment.
The highlight of the upgraded experiment is the larger acceptance of the high position resolution part of the zero-degree calorimeter(ZDC). We found the detector technology developed for the FoCAL upgrade project of the ALICE experiment at LHC well satisfies
the RHICf-II performance requirement. We thus resumed the associated membership of the ALICE collaboration and the RHICf-II
detectors are to be developed together with the FoCAL collaboration. This new detector technology development is also a part of the
R&D program for the essential ZDC detector for EIC.

Members
Director
Hideto EN’YO
Vice Chief Scientist
Yasuyuki AKIBA
Research/Technical Scientist
Yuji GOTO (Senior Research Scientist)
Itaru NAKAGAWA (Senior Research Scientist)
Seidl RALF (Senior Research Scientist)

Yasushi WATANABE (Senior Research Scientist)
Satoshi YOKKAICHI (Senior Research Scientist)

Contract Researcher
Tomonori TAKAHASHI
Special Postdoctoral Researcher
Koki KANNO
Research Associate
Wataru NAKAIInternational Program Associates
Minho KIM (Korea Univ.)

Benard MULILO (Korea Univ.)

Senior Visiting Scientist
Toshiaki SHIBATA (Nihon Univ.)
Visiting Scientists
Kazuya AOKI (KEK)Se Young HAN (Korea Univ.)
Shoichi HASEGAWA (JAEA)
Takashi KONDO (Tokyo Metropolitan Industrial Tech. Res.
Inst.)
Shunzo KUMANO (KEK)
Tsutomu MIBE (KEK)
Yuhei MORINO (KEK)
Student Trainees
Sakiko ASHIKAGA (Kyoto Univ.)
Ryohei FUJII (Kyoto Univ.)
Kaede KAMANO (Nara Women’s Univ.)
Takehito KONDO (Hiroshima Univ.)
Yoko MINATO (Nara Women’s Univ.)

Ken-ichi NAKANO (Tokyo Tech)
Megumi NARUKI (Kyoto Univ.)
Kyoichiro OZAWA (KEK)
Susumu SATO (JAEA)
Kenta SHIGAKI (Hiroshima Univ.)
Maya SHIMOMURA (Nara Women’s Univ.)
Kiyoshi TANIDA (JAEA)

Seiya MIYATA (Univ. of Tokyo)
Tomoki MURAKAMI (Univ. of Tokyo)
Satomi NAKASUGA (Kyoto Univ.)
Junsang PARK (Seoul Nat’l Univ.)
Kenta SATO (Nagoya Univ.)- 363 -

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Ayaka SUZUKI (Nara Women’s Univ.)
Kazuki SUZUKI (Kyoto Univ.)

Yosuke UEDA (Hiroshima Univ.)
Jaehee YOO (Korea Univ.)

InternAyaka SUZUKI (Nara Women’s Univ.)
AssistantKeiko SUZUKI

List of Publications & Presentations
Publications[Original papers]
C. Aidala et al. (PHENIX Collaboration), “Measurements of µ µ pairs from open heavy flavor and Drell-Yan in p + p collisions at√
sNN = 200 GeV,” Phys. Rev. D 99, 072003 (2019).
C. Aidala et al. (PHENIX Collaboration), “Nonperturbative-transverse-momentum broadening in dihadron angular correlations in√
sNN = 200 GeV proton-nucleus collisions,” Phys. Rev. C 99, 044912 (2019).
A. Adare et al. (PHENIX Collaboration), “Measurement of two-particle correlations with respect to second- and third-order event planes√in Au + Au collisions at sNN = 200 GeV,” Phys. Rev. C 99, 054903 (2019).
C. Aidala et al. (PHENIX Collaboration), “Measurement of charm and bottom production from semileptonic hadron decays in p + p√
collisions at sNN = 200 GeV,” Phys. Rev. D 99, 092003 (2019).
A. Adare et al. (PHENIX Collaboration), “Beam energy and centrality dependence of direct-photon emission from ultra-relativistic
heavy-ion collisions,” Phys. Rev. Lett. 123, 022301 (2019).
C. Aidala et al. (PHENIX Collaboration), “Nuclear dependence of the transverse single-spin asymmetry in the production of charged√
hadrons at forward rapidity in polarized p + p, p + Al, and p + Au collisions at sNN = 200 GeV,” Phys. Rev. Lett. 123, 122001 (2019).
√
U. A. Acharya et al. (PHENIX Collaboration), “J/Ψ and Ψ (2S) production at forward rapidity in p + p collisions at sNN = 510 GeV,”
Phys. Rev. D 101, 052006 (2020).
C. Aidala et al. (PHENIX Collaboration), “Nuclear-modification factor of charged hadrons at forward and backward rapidity in p + Al√
and p + Au collisions at sNN = 200 GeV,” Phys. Rev. C 101, 034910 (2020).
C. A. Aidala, Y. Goto, et al., “The SeaQuest spectrometer at fermilab,” Nucl. Instrum. Methods Phys. Res. A 930, 49–63 (2019).
M. H. Kim, Y. Goto, I. Nakagawa, √J. S. Park, R. Seidl, et al., “Transverse single-spin asymmetry for very forward neutral pion productionin polarized p + p collisions at s = 510 GeV,” Phys. Rev. Lett. 124, 252501 (2019).
M. Ichikawa et al., “Trigger merging module for the J-PARC E16 experiment,” IEEE Trans. Nucl. Sci. 66, 2022 (2019).

[Proceedings]
A. Dote, Y. Goto, A. Hosaka, S. Kumano, and A. Monnai, “Proceedings, 8th international conference on quarks and nuclear physics(QNP2018),” JPS Conf. Proc. 26 (2019).
A. Chen, Y. Goto, et al., “Probing nucleon’s spin structures with polarized Drell-Yan in the fermilab SpinQuest experiment,” PoS
SPIN2018, 164 (2019).
Y. Itow, Y. Goto, I. Nakagawa, R. Seidl, J. S. Park, M. H. Kim, et al., “Recent results from the LHCf and RHICf experiments,” EPJ Web
Conf. 208, 05004 (2019).
0
M. H. Kim, Y. Goto, I. Nakagawa, R. Seidl, J. S. Park,√ M. H. Kim, et al., “Transverse single spin asymmetry for very forward π
production in polarized proton-proton collisions at s = 510 GeV,” EPJ Web Conf. 208, 05007 (2019).
Y. Goto, “Asymmetry measurement of very forward neutral particle production in the RHICf experiment,” Acta Phys. Polon. B Proc.
Suppl. 12, 837 (2019).
S. Ashikaga et al., (J-PARC E16 Collaboration), “Measurement of vector meson mass in nuclear matter at J-PARC,” JPS Conf. Proc. 26,
024005 (2019).

Presentations[International conferences/workshops]
Y. Goto (invited), “Nucleon structure study at RHIC and EIC,” YKIS2018b Symposium on Recent Developments in Quark-Hadron
Sciences, Kyoto, Japan, June 12, 2018.
Y. Goto (invited), “Asymmetry measurement of very forward neutral particle production in the RHICf experiment,” Diﬀraction and Low-x
2018, Reggio Calabria, Italy, August 29, 2018.
Y. Goto (oral), “Very forward neutral particle measurement in the RHICf experiment,” 5th Joint Meeting of the APS Division of Nuclear
Physics and the Physics Society of Japan, Hawaii, USA, October 26, 2018.
Y. Goto (invite), “Electron-ion collider project,” Workshop on Progress on Hadron Structure Functions in 2018, Tsukuba, Japan, November 19, 2018.
Y. Goto (invited), “Forward spin physics at PHENIX and sPHENIX,” International Workshop on Forward Physics and Forward Calorimeter Upgrade in ALICE, Tsukuba, Japan, March 7, 2019.
Y. Goto (invited), “RHICf results,” Cold QCD Workshop, RHIC & AGS Annual Users’ Meeting, Upton, New York, USA, June 4, 2019.

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Y. Goto (invited), “Plan for EIC (Electron-Ion Collider),” 14th ANPhA Board meeting and Symposium in Korea, Jeju Island, Korea, June
28, 2019.
Y. Goto (invited), “Overview of future facilities for nucleon spin studies,” 11th Circum-Pan-Pacific Symposium on High Energy Spin
Physics (Pacific Spin 2019), Miyazaki, Japan, August 30, 2019.
Y. Goto (invited), “Physics and detector requirements at zero degree of EIC,” Workshop on Forward Physics and QCD at the LHC, thefuture Electron Ion Collider and Cosmic Ray Physics, Guanajuato, Mexico, November 19, 2019.
S. Yokkaichi (invited), “Measurement of the spectral change of vector mesons in nuclei at the high-momentum beam line in J-PARC
HEF,” J-PARC Symposium 2019, Tsukuba, Japan, September 23–26, 2019.
S. Ashikaga, “Measurement of vector meson mass in nuclear matter at J-PARC,” The 8th International Conference on Quarks and Nuclear
Physics (QNP2018), Tsukuba, Japan, November 13–17, 2018.
M. Ichikawa, “Trigger merging module for the J-PARC E16 experiment,” 21st IEEE Real Time ConferenceRT2018 (RT2018), Williamsburg, VA, USA, June 12, 2018.

[Domestic conferences/workshops]‫ޙ‬౻༤ೋʢট଴ߨԋʣ, ʮElectron-Ion Collider (EIC) ‫ܭ‬ըʯ, ೔ຊֶज़ձٞެ։γϯϙδ΢Ϝʮૉཻࢠ෺ཧɾ‫֩ࢠݪ‬෺ཧ෼໺ͷେ‫ܕ‬ࢪઃ‫ܭ‬ըɾେ‫ن‬໛‫ܭڀݚ‬ըϚελʔϓϥϯʯ, ౦‫ژ‬, 2019 ೥ 2 ݄ 19 ೔.
‫ޙ‬౻༤ೋ (ট଴ߨԋʣ, “Progress on RHIC-spin physics,” Progress on QCD and Nucleon Structure in 2019, ͭ͘͹, 2019 ೥ 2 ݄ 28 ೔.
‫ޙ‬౻༤ೋ (‫ޱ‬಄ൃදʣ, ʮPHENIX ࣮‫Ͱݧ‬ͷภ‫ۃ‬ཅࢠ + ‫֩ࢠݪ‬িಥʹΑΔ࠷৽ͷ݁Ռʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ,ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17 ೔.
ଜ্ஐ‫ޱ( ل‬಄ൃදʣ, ʮJ-PARC E16 ࣮‫͚ͨ޲ʹݧ‬ඈ੻‫ݕ‬ग़‫ث‬ͷ։ൃ͓ΑͼੑೳධՁʯ, ೔ຊ෺ཧֶձୈ 74 ճ೥࣍େձ, ‫۝‬भେֶҏ౎Ωϟϯύε, ෱Ԭ, 2019 ೥ 3 ݄ 14–17 ೔.
࢛೔ࢢ‫ ޛ‬ʢট଴ߨԋʣ, ʮ‫֩ࢠݪ‬தͰͷϕΫτϧதؒࢠͷ࣭ྔมԽͷଌఆʯ, ELPH ‫ڀݚ‬ձ C023ʮ‫֩ࢠݪ‬தʹ͓͚Δϋυϩϯͷੑ࣭ͱΧΠϥϧରশੑͷ໾ׂʯ, ౦๺େֶిࢠޫཧֶ‫ڀݚ‬ηϯλʔ, ઋ୆, 2018 ೥ 9 ݄ 11–12 ೔.

Press releasesʮཅࢠিಥ͔Βͷࠨӈඇରশੑͳ pi தؒࢠͷੜ੒ʯ, ཧԽֶ‫ॴڀݚ‬, ౦‫ژ‬େֶӉ஦ઢ‫ॴڀݚ‬, ໊‫ݹ‬԰େֶ, ೔ຊ‫ڀݚྗࢠݪ‬։ൃ‫ߏػ‬,2020 ೥ 6 ݄ 23 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
Meson Science Laboratory
1. Abstract
Particles like muons, pions, and kaons have finite life times, so they do not exist in natural nuclei or matters. By implanting theseparticles into nuclei/matters, exotic phenomena in various objects can be studied from new point of view.
For example, kaon is the second lightest meson, which has strange quark as a constituent quark. It is expected that if one embeds
mesons into nuclei, the sizes of the nuclei become smaller and one can form a high-density object beyond the normal nuclear density.
Study of this object could lead to better understanding of the origin of the mass of the matter, and may reveal the quark degree of
freedom beyond the quark-confinement. The other example is the weak interaction in nuclear matter. It can only be studied by the
weak decay of hypernuclei, which have Lambda particle in the nuclei.
Muon provides even wider scope of studies, covering condensed matter physics as well as nuclear and atomic physics, and weare trying to extend the application field further into chemical and biological studies. For instance, stopping positively charged muonin a material, we obtain information on the magnetic properties or the local field at the muon trapped site (µSR). Injecting negatively
charged muon to hydrogen gas, muonic hydrogen atom (µp) is formed. We are planning to measure µp hyperfine splitting energy tomeasure proton magnetic radius, which is complementary quantity to the proton charge radius and its puzzle. We are also interested
in precision measurement of muon property itself, such as muon anomalous magnetic moment (g − 2).
In our research, we introduce diﬀerent kind of impurities into nuclei/matters, and study new states of matter, new phenomena, or
the object properties.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Study of meson property and interaction in nuclei
Origin of matter mass/quark degree of freedom in nuclei
Condensed matter and material studies with muon
Nuclear and particle physics studies via muonic hydrogen
Development of ultra cold muon beam, and its application from material science to particle physics

3. Summary of Research Activity(1) Hadron physics at J-PARC, RIKEN-RIBF, GSI and SPring-8
Kaon and pion will shed a new insight to the nuclear physics. The recent discovery of deeply bound pionic atom enables us toinvestigate the properties of mesons in nuclear matter. At RIKEN-RIBF, we are preparing precise experimental study of the pionicatom. Very lately, we succeeded to discover kaonic nuclear bound state, “K-pp,” at J-PARC. The yield dependence on momentumtransfer shows that observed system is unexpectedly small. We extended our study on Λ(1405) that could be K − p bound state. By
these experiments, we are studying the K̄N interaction, and clarify the nature of kaon in nuclei. At Spring-8 and at GSI, we areplanning to study omega and η′ nuclei. By these experiments, we aim to be a world-leading scientific research group using these lightmeta-stable particles.
(1-1) Deeply bound kaonic nuclei
J-PARC E15 experiment had been performed to explore the simplest kaonic nuclear bound state, “K − pp”. Because of the strong
attraction between K̄N, the K̄ in nuclei may attract surrounding nucleons, resulting in forming a deeply bound and extremely dense
object. Measurement of the kaon properties at such a high-density medium will provide precious information on the origin of hadron
masses, if the standard scenario of the hadron-mass-generation mechanism, in which the hadron masses are depends on matter densityand energy, is correct. Namely, one may study the chiral symmetry breaking of the universe and its partial restoration in nuclear
medium.
The E15 experiment was completed to observe the “K − pp” bound state by the in-flight 3 He(K − , n) reaction, which allows us
the formation via the invariant-mass spectroscopy by detecting decay particles from “K − pp”. For the experiment, we constructed a
dedicated spectrometer system at the secondary beam-line, K1.8BR, in the hadron hall of J-PARC.
With the Λpn final states obtained in the first stage experiment, we observed a kinematic anomaly in the Λp invariant mass
near the mass threshold of M(K − pp) (total mass of kaon and two protons) at the lower momentum transfer q region. We conducteda successive experiment to examine the nature of the observed kinematical anomaly in the Λpn final state, and we confirmed theexistence of the bound state below the mass threshold of M(K − pp) at as deep as the binding energy of 40 MeV. The momentum
transfer q naturally prefers lower momentum for the bound state formation, but the observed event concentration extended having theform-factor parameter ∼400 MeV/c. Based on the PWIA calculation, the data indicated that the “K − pp” system could be as small as∼0.6 fm. It is astonishingly compact in contrast to the mean nucleon distance ∼1.8 fm.
This observed signal shows that a meson ( q̄q) forms a quantum state where baryons (qqq) exist as nuclear medium, i.e., a highly
excited novel form of nucleus with a kaon, in which the mesonic degree-of-freedom still holds. This is totally new form of nuclear
system, which never been observed before.
(1-2) Precision X-ray measurement of kaonic atom
To study the K̄N interaction at zero energy from the atomic state level shift and width of kaon, we have performed an X-ray
spectroscopy of atomic 3d → 2p transition of negatively charged K-mesons captured by helium atoms. However, our first experimentis insuﬃcient in energy resolution to see the K − -nucleus potential. Aiming to provide a breakthrough from atomic level observation,- 366 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

we introduce a novel X-ray detector, namely superconducting transition-edge-sensor (TES) microcalorimeter oﬀering unprecedented
high energy resolution, being more than one order of magnitude better than that achieved in the past experiments using conventional
semiconductor detectors. The experiment J-PARC E62 aims to determine 2p-level strong interaction shifts of kaonic 3 He and 4 He
atoms by measuring the atomic 3d → 2p transition X-rays using TES detector with 240 pixels having about 23 mm2 eﬀective area
and the average energy resolution of 7 eV (FWHM) at 6 keV. We carried out the experiment at J-PARC in June 2018 and successfully
observed distinct X-ray peaks from both atoms. The data analysis is now ongoing.
Another important X-ray measurement of kaonic atom would be 2p → 1 s transition of kaonic deuteron (K − -d). We havemeasured same transition of kaonic hydrogen (K − -p), but the width and shift from electro-magnetic (EM) value reflect only isospin
average of the Kbar N interaction. We can resolve isospin dependence of the strong interaction by the measurements both for K − -p andK − -d. The experiment J-PARC E57 aims at pioneering measurement of the X-rays from K − -d atoms. Prior to full (stage-2) approvalof the E57 proposal, we performed a pilot run with hydrogen target in March 2019.
(1-3) Deeply bound pionic atoms and η′ mesonic nuclei
We have been working on precision spectroscopy of pionic atoms systematically, which leads to understanding of the non-trivial
structure of the vacuum and the origin of hadron masses. The precision data set stringent constraints on the chiral condensate at
nuclear medium. We are presently preparing for the precision systematic measurements at RIBF. A pilot experiment performed in2010 showed a unprecedented results of pionic atom formation spectra with finite reaction angles. The measurement of pionic 121 Sn
performed in 2014 showed a very good performance of the system. We have been analyzing the data to achieve information on thepion-nucleus interaction based on the pionic atom spectroscopy.
We are also working on spectroscopy of η′ mesonic nuclei in GSI/FAIR. Theoretically, peculiarly large mass of η′ is attributed
to UA(1) symmetry and chiral symmetry breaking. As a result, large binding energy is expected for η′ meson bound states in nuclei(η′ -mesonic nuclei). From the measurement, we can access information about gluon dynamics in the vacuum via the binding energy
and decay width of η′ -nuclear bound state.
(1-4) 3 Λ H lifetime puzzle and our approach
Three recent heavy ion experiments (HypHI, STAR, and ALICE) announced surprisingly short lifetime for 3 Λ H hyper-nucleus’s
Mesonic Weak Decay (MWD), which seems to be inconsistent with the fact that the 3 Λ H is a very loosely bound system. It is very
interesting to study this with a diﬀerent experimental approach. We proposed a direct measurement of 3 Λ H MWD lifetime with ∼20%
resolution at J-PARC hadron facility by using K − meson beam at 1 GeV/c. As for the feasibility test, we also measure 4 Λ H lifetime.
A Cylindrical Detector System (CDS) used in J-PARC E15/E31 experiment is employed to capture the delayed π− as a weak
decay product from 3, 4 Λ H; a calorimeter is installed in the very forward region to tag fast π0 meson emission at ∼0 degree, which
ensures that the Λ hyperon production with small recoil momentum. By this selection, we can improve the ratio between 3, 4 Λ H andquasi-free Λ and Σ background. A test beam for feasibility study with 4 He target has been conditionally approved by J-PARC PAC.
We will conduct the experiment and to present the data in short.
(2) Muon science at RIKEN-RAL branch
The research area ranges over particle physics, condensed matter studies, chemistry and life science. Our core activities are
based on the RIKEN-RAL Muon Facility located at the Rutherford-Appleton Laboratory (UK), which provides intense pulsed-muonbeams. We have variety of important research activities such as particle/nuclear physics studies with muon’s spin and condensed
matter physics by muon spin rotation/relaxation/resonance (µSR).
(2-1) Condensed matter/materials studies with µSR
To improve our two µSR spectrometers, ARGUS (Port-2) and CHRNUS (Port-4), we adjusted the threshold level of the muondetector system for the zero-field condition. At this condition, we optimized the eﬃciency of the detector system and the counting rate
was improved nearly 50% without any deformation of the time spectrum.
Among our scientific activities on µSR studies from year 2016 to 2019, following studies are most important subjects of materialsciences at the RIKEN-RAL muon facility:(1) Deformed nodal superconducting gap state and asymmetric spin-fluctuation mediated Cooper pair in the quasi twodimensional organic superconductor Λ-[BETS]2 GaCl4(2) Multi magnetic transitions in the Ru-based pyrochlore systems, R2 Ru2 O7 .
(3) Magnetic properties of the nano-cluster gold in the border of macro- and micro- scale.
(4) Novel magnetic and superconducting properties of nano-size La-based high-TC superconducting curates.
(5) Determination of muon positions estimated from density functional theory (DFT) and dipole-field calculations.
(6) Chemical muonic states in DNA molecules.
(2-2) Nuclear and particle physics studies via ultra-cold muon beam and muonic atoms
If we can improve muon beam emittance, timing and energy dispersion (so-called “ultra-cold muon”), then the capability of µSR
studies will be drastically improved. The ultra-cold muon beam can stop in a thin foil, multi-layered materials and artificial lattices, so
one can apply the µSR techniques to surface and interface science. The development of ultra-cold muon beam is also very importantas the source of pencil-like small emittance muon beam for muon g-2 measurement.
Ultra-cold muon beam has been produced by laser ionization of muoniums in vacuum (bound system of µ+ and electron). We
are developing two key components, high eﬃciency muonium generator at room temperature and high intensity ionization laser. The
study of muonium generator has been done in collaboration with TRIUMF. In 2013, we demonstrated at least 10 times increase of
the muonium emission eﬃciency by fabricating fine laser drill-holes on the surface of silica aerogel. Further study was done in 2017with more than 20 aerogel target having diﬀerent surface conditions. We are analyzing the data to identify which condition most- 367 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

contributed to increasing the muonium emission eﬃciency. We also developed a high power Lyman-α laser in collaboration with lasergroup at RIKEN. In this laser development, we succeeded to synthesize novel laser crystal Nd:YGAG, which has an ideal wavelength
property for laser amplification to generate Lyman-α by four-wave mixing in Kr gas cell. We already achieved 10 times increase of
Lyman-α generation than before. However, in order to increase the intensity by one more order, we need a larger size crystal. So far
we have inhomogeneity problem but we are trying to solve this problem.
Concerning the muonic atom, we are planning a new precise measurement of proton radius. A large discrepancy was foundrecently in the proton charge radius between the new precise value from muonic hydrogen atom at PSI and those from normal hydrogen spectroscopy and e-p scattering. We propose a precise measurement of Zemach radius (with charge and magnetic distributions
combined) using the laser spectroscopy of hyperfine splitting energy in the muonic hydrogen atom. As a key parameter for designing
the experiment, we need the quench rate of the muonic proton polarization due to collision with surrounding protons, for which only
theoretical estimations are available. We successfully measured the quench rate of muonic deuterium polarization in deuterium gas,
which confirmed the long lifetime consistent with the calculation. In this fiscal year, we carried out measurement on muonic proton in
low pressure hydrogen gas.

Members
Director
Masahiko IWASAKI
Research Scientists
Kenta ITAHASHI (Senior Research Scientist)
Yue MA (Senior Research Scientist)
Haruhiko OUTA (Senior Research Scientist)

Fuminori SAKUMA (Senior Research Scientist)
Isao WATANABE (Senior Research Scientist)

Contract Researcher
Katsuhiko ISHIDA
Junior Research Associates
Julia ANGEL (Hokkaido Univ.)
Shun SEO (Univ. of Tokyo)

Muhamad UMAR (Hokkaido Univ.)

International Program Associates
Muhammad H.B. CHE LAH (Univ. Sains Malaysia)
Redo Muhammad RAMADHAN (Univ. Indonesia)
Harison B. ROZAK (Univ. Sains Malaysia)

Suci WINARSIH (Univ. Indonesia)
Utami WIDYAISWARI (Univ. Indonesia)

Research Consultant
Masayasu KAMIMURA
Senior Visiting Scientists
Hiroyuki NOUMI (Osaka Univ.)

Kazuhiro TANAKA (KEK)

Visiting Scientists
Tadashi ADACHI (Sophia Univ.)
Hiroko ARIGA (Hokkaido Univ.)
Retno ASIH (Inst. Teknologi Sepuluh Nopember)
Fahmi ASTUTI (Inst. Teknologi Sepuluh Nopember)
KwangYong CHOI (Chung-Ang Univ.)
Catalina Oana CURCEANU (INFN)
Zyun EZAWA (Tohoku Univ.)
Hiroyuki FUJIOKA (Tokyo Tech)
Takayuki GOTO (Sophia Univ.)
Maryam HASSANVAND (Isfahan Univ. of Tech.)
Wataru HIGEMOTO (JAEA)
Ko-ichi HIRAKI (Fukushima Medical Univ.)
Satoru HIRENZAKI (Nara Women’s Univ.)
Koichi ICHIMURA (Hokkaido Univ.)
Yasuyuki ISHII (Shibaura Inst. of Tech.)
Ryosuke KADONO (KEK)
Takayuki KAWAMATA (Tohoku Univ.)
Seiko KAWAMURA (JAEA)
Takuya KOBAYASHI (Saitama Univ.)
Yoji KOIKE (Tohoku Univ.)

Seungwon LEE (Univ. of Toyama)
Kenji MATSUDA (Univ. of Toyama)
Mototsugu MIHARA (Osaka Univ.)
Yasuhiro MIYAKE (KEK)
Mohamed Ismail MOHAMED-IBRAHIM (Univ. Sains
Malaysia)
Takehito NAKANO (Ibaraki Univ.)
Takahiro NAMIKI (Univ. of Toyama)
Katsuhiko NISHIMURA (Univ. of Toyama)
Yasuo NOZUE (Osaka Univ.)
Agustinus NUGROHO (Inst. Teknologi Bandung)
Kazuki OHISHI (Comprehensive Res. Org. for Sci. and Soc.)
Yu OISHI (KEK)
Atsushi OKAZAWA (Univ. of Tokyo)
Amba D. PANT (Ibaraki Univ.)
Dita PUSPITA SARI (Shibaura Inst. of Tech.)Irwan RAMLI (Univ. Cokroaminoto Palopo)
Yuta SADA (Osaka Univ.)
Lusi SAFRIANI (Univ. Padjadjaran)
Naohito SAITO (KEK)- 368 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Ichiro SHIRAKI (Univ. of Yamanashi)
Shukri SULAIMAN (Univ. Sains Malaysia)
Ken SUZUKI (Stefan Meyer Inst.)
Kensuke SUZUKI (Tohoku Univ.)
Takao SUZUKI (Shibaura Inst. of Tech.)Tomohiro TAKAYAMA (Max Planck Inst.)
Yoshiki TANAKA (GSI)
Hiroshi TANIDA (Toyama Prefectural Univ.)

Andrea VACCHI (INFN)
Eberhard WIDMANN (Stefan Meyer Inst.)
Zhuan XU (Zhejiang Univ.)
Ichihiro YAMAUCHI (Saga Univ.)
Toshimitsu YAMAZAKI (Univ. of Tokyo)
Masaru YOSOI (Osaka Univ.)
Xu-Guang ZHENG (Saga Univ.)
Johann ZMESKAL (Austrian Academy of Sci.)

Student Trainees
Irwan RAMLI (Hokkaido Univ.)
Shu AIKAWA (Tokyo Tech)

Tanawat SAWASDEE (Suranaree Univ. of Tech.)Part-time Worker
Mayumi YOSHIMURA (Administrative Part-time Worker II)
Assistants
Yoko FUJITA
Kumiko TAKAHASHI

Mitsue YAMAMOTO

List of Publications & Presentations
Publications[Original papers]
M. Clemenza, et al., “Muonic atom X-ray spectroscopy for non-destructive analysis of archaological samples,” Journal of Radioanalyticaland Nuclear Chemistry 322, 1357–1363 (2019).
B. V. Hampshire, K. Butcher, K. Ishida, G. Green, D. Paul, and A. Hillier, “Using negative muons as a probe for depth profiling silver
Roman coinage,” Heritage 2, 400–407 (2019).
S. Asano, K. M. Suzuki, K. Kudo, I. Watanabe, A. Koda, R. Kadono, T. Noji, Y. Koike, T. Taniguchi, S. Kitagawa, K. Ishida, and M. Fujita,“Oxidation annealing eﬀects on the spin-glass-like magnetism and appearance of superconductivity in T*-type La1−x/2 Eu1−x/2 Sr x CuO4
(0.14 ≦ x ≦ 0.28),” J. Phys. Soc. Jpn. 88, 084709/1-6 (2019).
F. Astuti, M. Miyajima, T. Fukuda, M. Kodani, T. Nakano, T. Kambe, and I. Watanab, “Anionogenic magnetism combined with latticesymmetry in alkali-metal superoxide RbO2 ,” J. Phys. Soc. Jpn. 88, 043701/1-5 (2019).
M. A. Baqiya, T. Adachi, A. Takahashi, T. Konno, T. Ohgi, I. Watanabe, and Y. Koike, “Muon-spin relaxation study of the spin correlationsin the overdoped regime of electron-doped high-T C cuprate superconductors,” Phys. Rev. B 100, 064514/1-5 (2019).
S. Wenner, C. Marioara, K. Nishimura, K. Matsuda, S. Lee, T. Namiki, I. Watanabe, T. Matsuzaki, and R. Holmestad, “Muon spin
relaxation study of solute-vacancy interactions during natural aging of Al-Mg-Si-Cu alloys,” Metallurgical and Materials Transactions
A 50, 3446–3451 (2019).
T. Suzuki, K. Katayama, I. Watanabe, and H. Tanaka, “Spin-fluctuating ground state in the spin-1/2 kagome lattice (Rb1−x Cs x )2 Cu3 SnF12
with x = 0.53 observed by muon spin relaxation,” J. Phys. Soc. Jpn. 89, 074701 (2020).
K. M. Suzuki, S. Asano, H. Okabe, A. Koda, R. Kadono, I. Watanabe, and M. Fujita, “Successive magnetic ordering sequence observed
from muon spin rotation in T’-structured R2 CuO4 (R = Nd, Eu),” Phys. Rev. B (in press).
H. Yamauchi, D. P. Sari, I. Watanabe, Y. Yasui, L. -J. Chang, K. Kondo, T. U. Ito, M. Ishikado, M. Hagihara, M. D. Frontzek, S. Chi,
J. A. Fernandez-Baca, J. S. Lord, A. Berlie, A. Kotani, S. Mori, and S. Shamoto, “High-temperature short-range order in Mn3 RhSi,”
Commun. Mater. (in press).
K. Oinuma, N. Okano, H. Tsunakawa, S. Michimura, T. Kobayashi, H. Taniguchi, K. Satoh, J. Angel, I. Watanabe, Y. Ishii, H. Okamoto,and T. Itou, “Spin structure at zero magnetic field and field-induced spin reorientation transitions in a layered organic canted antiferromagnet bordered on a superconducting phase,” Phys. Rev. B (in press).
M. Fujita, K. M. Suzuki, S. Asano, H. Okabe, A. Koda, R. Kadono, and I. Watanabe, “New aspects of magnetism in T’-type Eu2 CuO2
revealed by precise muon spin rotation/relaxation measurements,” Phys. Rev. B (in press).

[Review articles]
H. Ohnishi, F. Sakuma, and T. Takahashi, “Hadron physics at J-PARC,” Prog. Part. Nucl. Phys., (in press)[Books]‫࡚ؠ‬խ඙, ࠤ‫࢙ؒٱ‬య, ࢁզ୓າ, ʮ࠷ۙͷ‫͔ڀݚ‬ΒɿK தؒࢠͱཅࢠ 2 ͔ͭΒͳΔ “‫֩ࢠݪ ”ͳົح‬ʯ, ೔ຊ෺ཧֶձࢽ, 2020 ೥ 1
݄߸ ୈ 75 ‫ר‬ୈ 1 ߸ʢ௨‫ ר‬855 ߸ʣpp. 10–15.

[Proceedings]
S. Kawasaki et al., “Λ(1405) spectroscopy via the in-flight d(K − , n) reaction at the J-PARC K1.8BR,” JPS Conf. Proc. 26, 022009 (2019).
T. Yamaga et al., “Results of KbarNN search via the (K − , n) reaction at J-PARC,” JPS Conf. Proc. 26, 023008 (2019).
T. Hashimoto et al., “Kaonic atom experiments at J-PARC,” JPS Conf. Proc. 26, 023013 (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

H. Asano et al., “Spectroscopic study of the Λ(1405) resonance via the d(K − , n) reaction at J-PARC,” AIP Conf. Proc. 2130, 040018(2019).
Y. K. Tanaka et al., “Spectroscopy of η′ -mesic nuclei with WASA at GSI/FAIR,” Acta Phys. Polon. B 51, 39 (2020).

Presentations[International conferences/workshops]
F. Sakuma (invited), “K − pp bound system at J-PARC,” The 15th International Conference on Meson-Nucleon Physics and the Structureof the Nucleon (MENU-2019), Cohon University Center, Carnegie Mellon University, Pittsburgh Pennsylvania, June 2–7, 2019.
K. Itahashi (invited), “Mesons in nuclei: review and perspectives,” 3rd Jagiellonian Symposium on Fundamental and Applied Subatomic
Physics, Krakow, June 23–28, 2019.
K. Itahashi (oral), “Precision spectroscopy of pionic atoms at RIBF,” The 27th International Nuclear Physics Conference (INPC 2019),
Glasgow, UK, July 29–August 2, 2019.
T. Yamaga (oral), “Result of KbarNN search via exclusive measurements of (K − , n) reaction at J-PARC,” The 27th International Nuclear
Physics Conference (INPC 2019), Glasgow, UK, July 29–August 2, 2019.
S. Okada (oral), “Kaonic atom X-ray spectroscopy with superconducting detector,” The 27th International Nuclear Physics Conference(INPC 2019), Glasgow, UK, July 29–August 2, 2019.
T. Hashimoto (oral), “Towards the X-ray measurement of kaonic deuterium at J-PARC,” The 27th International Nuclear Physics Conference (INPC 2019), Glasgow, UK, July 29–August 2, 2019.
K. Ishida, “Status of the g − 2 and EDM experiment at J-PARC,” FCCP2019, Anacapri, Italy, August 2019.
K. Ishida, “Measurement of the proton Zemach radius from the hyperfine splitting in muonic hydrogen utilizing muon spin repolarization
with laser: Principle and Method,” Proton Radius 2019, Veli Losinji, Croatia, September 2019.
S. Kanda, “Measurement of the proton Zemach radius from the hyperfine splitting in muonic hydrogen utilizing muon spin repolarization
with laser: Preparation Status,” Proton Radius 2019, Veli Losinji, Croatia, September 2019.
K. Ishida, “Status of the g − 2 and EDM experiment at J-PARC,” Proton Radius 2019, Veli Losinji, Croatia, September 2019.
M. Iwasaki (invited), “Kaonic nuclear bound state “K − pp” observation and possible future plan,” The 3rd J-PARC symposium (JPARC2019), Tsukuba, September 23–26, 2019.
K. Ishida et al., “Laser spectroscopy of the 1s hyperfine splitting energy of muonic hydrogen for the determination of proton Zemachradius,” The 3rd J-PARC symposium (J-PARC2019), Tsukuba, Japan, September 23–26, 2019.
M. Iwasaki (invited), “A novel and peculiar quantum system—K-meson and two protons bound state,” STRANEX: Recent progress andperspectives in STRANge EXotic atoms studies and related topics ECT*, Trento, October 21–25, 2019.
F. Sakuma (invited), “Λ(1405)pn Final State in the K − + 3 He reaction,” STRANEX: Recent progress and perspectives in STRANge
EXotic atoms studies and related topics ECT*, Trento, October 21–25, 2019.

[Domestic conferences/workshops]‫࡚ؠ‬խ඙ʢট଴ߨԋʣ, ʮK தؒࢠ ͱ̎ͭͷཅࢠ͕ଋറͨ͠‫ࢠྔͳົح‬ଟମ‫ܥ‬ʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2009 ೥ 9݄ 17–20 ೔.
O. Zhadyraʢ‫ޱ‬಄ൃදʣ, ʮThe physics E31 experiment to search the Λ(1405) via the d(K − , πΣ) reaction at J-PARC K1.8BRʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2009 ೥ 9 ݄ 17–20 ೔.
ࢁզ୓າʢট଴ߨԋʣ, ʮ൓ K தؒࢠϏʔϜΛ༻͍ͨ൓ K தؒࢠ‫֩ࢠݪ‬ͷ‫ڀݚ‬ʯ, ELPH ‫ڀݚ‬ձ C024ʮϋυϩϯߏ଄ʹ͓͚Δଟཻ
ࢠ૬ؔʯ, ౦๺େֶిࢠޫཧֶ‫ڀݚ‬ηϯλʔ, ઋ୆, 2019 ೥ 10 ݄ 16–17 ೔.
ؔ԰ྋฏ, ʮGSI ʹ͓͚Δ WASA ‫ݕ‬ग़‫ث‬Λ༻͍ͨϋΠύʔ֩෼ޫ࣮‫͓ݧ‬Αͼ η′ தؒࢠ‫ݧ࣮ࡧ୳֩ࢠݪ‬ͷͨΊͷϓϥενοΫγϯ
νϨʔλόϨϧͷ։ൃʢII)ʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2009 ೥ 9 ݄ 17–20 ೔.
ੴాউ඙, ʮӳࠃཧ‫ ݚ‬RAL ϛϡΦϯࢪઃͱϛϡΦϯར༻෼ੳʯ, ୈ 2 ճจཧ༥߹γϯϙδ΢Ϝ ྔࢠϏʔϜͰྺ࢙Λ୳Δ—Ճ଎‫ث‬͕๰͙จཧ༥߹ͷ஍ฏ—, େࡕ, 2019 ೥ 12 ݄.
দຊᠳଡ (‫ޱ‬಄ൃද), ʮߴਫ਼౓ύΠதؒࢠ‫ࢠݪ‬෼ޫ࣮‫ݧ‬ͷͨΊͷࡾ໘ަସ MWDC ͷ։ൃʯ, ೔ຊ෺ཧֶձ೥࣍େձ, 2020 ೥ 3 ݄.

[Seminars]
RIKEN Symposium, “International Workshop of Topological Quantum Materials,” Tainan, Taiwan, January 10–12, 2019.
RIKEN Symposium, “The 5th International Symposium in Current Progress in Mathematics and Sciences,” Depok, Indonesia, July 9–10,
2019.

AwardsS. Winarsih, RIKEN Summer School 2019, Poster Prize (in Physics).
S. Winarsih, RIKEN Summer School 2019, Poster Prize (Best Presentation).
S. Winarsih, RIKEN Exchange Meeting 2019, Poster Prize (Student Section), ཧ‫ݚ‬ӫๆ৆ ൘‫݈ڮ‬ଠ 2020 ೥ 3 ݄.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
RIKEN BNL Research Center
1. Abstract
The RIKEN BNL Research Center was established in April 1997 at Brookhaven National Laboratory with Professor T. D. Lee ofColumbia University as its initial Director. It is funded by the Rikagaku Kenkyusho (RIKEN, The Institute of Physical and Chemical
Research) of Japan. The Center is dedicated to the study of strong interactions, including spin physics, lattice QCD and RHIC
physics through the nurturing of a new generation of young physicists. Professor Lee was succeeded by BNL Distinguished Scientist,
N. P. Samios, who served until 2013. Dr. S. H. Aronson led the Center from 2013. After strong and significant leadership for 4 years,
S. Aronson stepped down from Director in March 31st 2017. Hideto En’yo succeeds from JFY 2017. Support for RBRC was initiallyfor five years and has been renewed four times, and presently extends to 2023. The Center is located in the BNL Physics Department.
The RBRC Theory Group activities are closely and intimately related to those of the Nuclear Theory, High Energy Theory, andLattice Gauge Theory Groups at BNL. The RBRC Experimental Group works closely with Radiation Laboratory at RIKEN, Wako,
the RHIC Spin Group at BNL, the RHIC Spin Physics community, and the PHENIX/sPHENIX collaboration. BNL provides oﬃce
space, management, and administrative support. In addition, the Computational Science Initiative (CSI) and Information Technology
Division (ITD) at BNL provide support for computing. The Deputy Director of RBRC is D. Morrison (BNL). D. Kharzeev (Stony
Brook/BNL) is leader of the Theory Group. Y. Akiba (RIKEN) is Experimental Group leader. T. Izubuchi (BNL) is Computing Group
leader.

2. Major Research Subjects
Major research subjects of the theory group are(1) Heavy Ion Collision(2) Perturbative QCD(3) Phenomenological QCD
Major research subjects of the computing group are(1) Search for new law of physics through tests for Standard Model of particle and nuclear physics(2) Dynamics of QCD and related theories(3) Theoretical and algorithmic development for lattice field theories, QCD machine design
Major research subject of the experimental group are(1) Experimental Studies of the Spin Structure of the Nucleon(2) Study of Quark-Gluon Plasma at RHIC
(3) sPHENIX detector construction

3. Summary of Research Activity
Summary of Research Activities of the three groups of the Center are given in the sections of each group.

Members
Director
Hideto EN’YO
Deputy Director
David P. MORRISON
Administrative Staﬀ
Kazushige FUKUSHIMA (Administration Manager, Nishina
Center and iTHEMS Promotion Oﬃce)
Hiroshi ITO (Deputy Administration Manager, Nishina Centerand iTHEMS Promotion Oﬃce)- 371 -

Pamela ESPOSITO (Administrative Assistant)
Maureen MCNEIL-SHEA (Administrative Assistant)

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
RIKEN BNL Research Center
Theory Group
1. Abstract
The eﬀorts of the RBRC theory group are concentrated on the major topics of interest in High Energy Nuclear Physics andstrongly interacting Chiral Matter. This includes: understanding of the Quark-Gluon Plasma; the nature of dense quark matter; theinitial state in high energy collisions, the Color Glass Condensate; its evolution through a Glasma; spin physics, as is relevant forpolarized hadronic collisions; physics relevant to electron-hadron collisions and the Electron-Ion Collider; quantum transport and the
Chiral Magnetic Eﬀect.
Theory Group hosted many joint tenure track positions with universities in U.S. and Japan.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Heavy Ion Collisions
Perturbative Quantum Chromo-Dynamics (QCD)
Phenomenological QCD
Chiral Matter

3. Summary of Research Activity(1) Phase diagram of QCD
The heavy ion program at Relativistic Heavy Ion Collider (RHIC) at BNL is focused on the study of the properties of QCD matterat high energy densities and high temperatures. The RBRC Theory group performs research that supports and guides the experimental
program at RHIC. In the past year, RBRC researchers had developed the theory of bulk viscosity’s behavior near the critical point andinvestigated universality-driven analytic structure of QCD crossover (V. Skokov).
Y. Kikuchi (in collaboration with K. Kashiwa and A. Tomiya) have developed a novel approach to the phase transitions using theneural network. In collaboration with R. Kobayashi, K. Shiozaki, and S. Ryu), Y. Kikuchi has proven a new theorem with higher-form
symmetry and applied it to the quantum dimer models.
(2) QCD Matter at High Energy Density and at small x
The RHIC experimental heavy ion program is designed to study the properties of matter at energy densities much greater thanthat of atomic nuclei. This includes the initial state of nucleus-nucleus collisions, the Color Glass Condensate, the intermediate state
to which it evolves, the Glasma, and lastly the thermal state to which it evolves, the Quark-Gluon Plasma. Theorists at the RBRC havemade important contributions to all of these subjects.
During the past year, D. Kharzeev and V. Skokov in their papers investigated the role of entanglement in gluon fields at small
Bjorken x in generating the azimuthal anisotropy of hadrons produced in AA and pA collisions at RHIC. It has been found that thesmall x gluon distributions are directly related to the entanglement entropy. D. Kharzeev, in collaboration with T. Ullrich and Z. Tu,
investigated the role of entanglement in explaining the LHC data on hadron multiplicity distributions, and proposed a program to study
entanglement at the EIC.
Y. Hatta has investigated the photoproduction of J/Ψ charmonium near the threshold and its link to the problem of the origin of
the proton’s mass. He has found that this process can be used to extract the proton mass distribution. Y. Hatta has also developed
the theory of spin dependence of Pomeron and Odderon in elastic scattering, and proposed a mechanism for single spin asymmetry
observed at RHIC. He has also made important contributions to developing the science program at the EIC.
Y. Mehtar-Tani has developed a theory of jet propagation through a dense QCD matter that properly takes into account the multiple
scattering eﬀects. He has also evaluated higher order QCD corrections to jet quenching, and proposed a dynamical grooming algorithm
for QCD jets.
C. Shen has advanced the applications of hydrodynamics to the description of heavy ion collisions, and built a quantitative modelfor the Beam Energy Scan at RHIC. In collaboration with Kharzeev and others, he has implemented the eﬀects of magnetic field on
the hydrodynamical evolution.
The activity of RBRC members described above bridges the gap between fundamental theory and phenomenology of heavy
ion collisions. This includes the lattice QCD studies, the analytical work on the dynamics of phase transitions, the development ofhydrodynamical and kinetic theory approaches incorporating quantum anomalies, and phenomenology. Much of the current work in
the field is based on the ideas originally developed by the RBRC theorists.
(3) Chiral Matter
Much of the work done at the RBRC Theory group has broad implications beyond the domain of Nuclear and High Energy
physics. One example is the Chiral Magnetic Eﬀect, originally proposed to occur in quark-gluon plasma, but discovered recently incondensed matter systems, so-called Dirac and Weyl semimetals (the original experimental observation of CME was made at BNL in
ZrTe5 in a paper co-authored by D. Kharzeev). It has become clear that RBRC can make a very substantial impact also on condensed
matter physics, where the methods developed at RBRC can be applied to a new set of problems. Vice versa, some of the new theoreticaldevelopments in condensed matter physics can be utilized for the study of QCD matter. Because of this, the RBRC developed a new- 372 -

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initiative on Chiral Matter focusing on the studies of quantum behavior in strongly interacting matter containing chiral fermions – thisincludes the quark-gluon plasma, electroweak plasma, Dirac and Weyl semimetals, and topological insulators.
In the past year, the RBRC members within this new initiative obtained a number of new results. Some of them, with a direct
relevance for the quark-gluon plasma, have been already described above; other results are of direct relevance for condensed matterphysics. D. Kharzeev and his students have proposed a new chiral magnetic photocurrent that has been observed experimentally.
Kharzeev in collaboration with Q. Li have developed a concept of a new type of “chiral qubit” based on Dirac and Weyl semimetals.
The Chiral Matter initiative has already broadened the impact of RBRC beyond the traditional domain of high-energy nuclear
physics, and has extended the RBRC research into a new and extremely active area.

Members
Group Leader
Dmitri KHARZEEV
Deputy Group Leaders
Yoshitaka HATTARBRC Researchers
Jordy DE VRIES
Yuta KIKUCHI
Yacine MEHTAR-TANI

Chun SHEN
Vladimir SKOKOV

Visiting Scientists
Hiromichi NISHIMURA (Keio Univ.)

Yuya TANIZAKI (North Carolina State Univ.)

List of Publications & Presentations
Publications[Original papers]
D. E. Kharzeev and Y. Kikuchi, “Real-time chiral dynamics from a digital quantum simulation,” Phys. Rev. Res. 2, 023342 (2020)
doi:10.1103/PhysRevResearch.2.023342 [arXiv:2001.00698 [hep-ph]].
S. Kaushik, D. E. Kharzeev, and E. J. Philip, “Transverse chiral magnetic photocurrent induced by linearly polarized light in symmetric
weyl semimetals,” [arXiv:2006.04857 [cond-mat.mes-hall]].
J. Garaud, M. N. Chernodub, and D. E. Kharzeev, “Vortices with magnetic field inversion in non-centrosymmetric superconductors,”[arXiv:2003.10917 [cond-mat.supr-con]].
U. Gürsoy, D. Kharzeev, E. Marcus, K. Rajagopal, and C. Shen, “Charge-dependent flow induced by electromagnetic fields in heavy ion
collisions,” [arXiv:2002.12818 [hep-ph]].
A. S. Gorsky and D. E. Kharzeev, “Tensor supercurrent in QCD,” Phys. Rev. D 101, 114002 (2020) doi:10.1103/PhysRevD.101.114002[arXiv:2001.07638 [hep-th]].
K. Hao, D. Kharzeev, and V. Korepin, “Bethe Ansatz for XXX chain with negative spin,” Int. J. Mod. Phys. A 34, 1950197 (2019)
doi:10.1142/S0217751X19501975 [arXiv:1909.00800 [hep-th]].
G. Inghirami, M. Mace, Y. Hirono, L. Del Zanna, D. E. Kharzeev, and M. Bleicher, “Magnetic fields in heavy ion collisions: flow andcharge transport,” Eur. Phys. J. C 80, 293 (2020) doi:10.1140/epjc/s10052-020-7847-4 [arXiv:1908.07605 [hep-ph]].
M. Chernodub, J. Garaud, and D. Kharzeev, [arXiv:1908.00392 [cond-mat.supr-con]].
D. Kharzeev, E. Shuryak, and I. Zahed, “Baryogenesis and helical magnetogenesis from the electroweak transition of the minimal Standard
Model,” [arXiv:1906.04080 [hep-ph]].
Z. Tu, D. E. Kharzeev, and T. Ullrich, “Einstein-podolsky-rosen paradox and quantum entanglement at subnucleonic scales,” Phys. Rev.
Lett. 124, 062001 (2020) doi:10.1103/PhysRevLett.124.062001 [arXiv:1904.11974 [hep-ph]].
X. G. Huang, D. E. Kharzeev, and H. Taya, “Real-time dynamics of axion particle production due to spontaneous decay of a coherent
axion field,” Phys. Rev. D 101, 016011 (2020) doi:10.1103/PhysRevD.101.016011 [arXiv:1904.08184 [hep-ph]].
D. Kharzeev and J. Liao, Nucl. Phys. News 29, 26–31 (2019) doi:10.1080/10619127.2018.1495479
D. E. Kharzeev and Q. Li, “The chiral qubit: quantum computing with chiral anomaly,” [arXiv:1903.07133 [quant-ph]].
S. Kaushik, D. E. Kharzeev, and E. J. Philip, “Chiral magnetic photocurrent in dirac and weyl materials,” Phys. Rev. B 99, 075150 (2019)
doi:10.1103/PhysRevB.99.075150 [arXiv:1810.02399 [cond-mat.mes-hall]].
Y. Hatta, “J/Ψ photo-production near threshold and the proton mass problem,” doi:10.1142/9789811214950 0035
Y. Hatta and Y. Zhao, “Parton distribution function for the gluon condensate,” [arXiv:2006.02798 [hep-ph]].
R. Boussarie and Y. Hatta, “QCD analysis of near-threshold quarkonium leptoproduction at large photon virtualities,” Phys. Rev. D 101,
114004 (2020) doi:10.1103/PhysRevD.101.114004 [arXiv:2004.12715 [hep-ph]].
Y. Hatta, “How EIC can help us to understand heavy-ion collisions,” [arXiv:2004.05336 [hep-ph]].
Y. Hagiwara, Y. Hatta, R. Pasechnik, and J. Zhou, “Spin-dependent Pomeron and Odderon in elastic proton-proton scattering,” Eur. Phys.
J. C 80, 427 (2020) doi:10.1140/epjc/s10052-020-8007-6 [arXiv:2003.03680 [hep-ph]].

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C. A. Aidala, E. Aschenauer, F. Aslan, A. Bacchetta, I. Balitsky, S. Benic, S. Bhattacharya, M. Boglione, M. Burkardt, J. Cammarota,
G. A. Chirilli, C. Cocuzza, A. Courtoy, D. de Florian, P. Di Nezza, A. Dumitru, S. Fucini, K. Fukushima, Y. Furletova, L. Gamberg,
O. Garcia-Montero, F. Gelis, V. Guzey, Y. Hatta, F. Hautmann, T. J. Hobbs, T. Horn, E. Iancu, S. Joosten, Z. B. Kang, R. Kishore,
Y. V. Kovchegov, P. Kroll, K. Kumerički, K. Kutak, T. Lappi, H. W. Lin, X. Liu, S. Liuti, C. Lorcé, H. Mäntysaari, C. Marquet,
Y. Makris, K. A. Mamo, Y. Mehtar-Tani, A. Metz, Z. E. Meziani, G. A. Miller, J. Miller, A. Mukherjee, P. M. Nadolsky, F. I. Olness,
B. Pasquini, B. Pire, C. Pisano, D. Pitonyak, M. V. Polyakov, A. Prokudin, J. W. Qiu, M. Radici, A. Rajan, S. Rajesh, M. Rinaldi,
K. Roy, C. Royon, N. Sato, M. Schlegel, G. Schnell, P. Schweitzer, S. Scopetta, R. Seidl, K. Semenov-Tian-Shansky, A. Signori,
D. Sokhan, A. M. Stasto, L. Szymanowski, A. Tarasov, D. Triantafyllopoulos, T. Ullrich, R. Venugopalan, I. Vitev, W. Vogelsang,
A. Vossen, B. T. Wang, S. Wallon, K. Watanabe, C. Weiss, B. W. Xiao, H. U. Yee, and Y. Zhao, “Probing nucleons and nuclei in highenergy collisions,” doi:10.1142/11684 [arXiv:2002.12333 [hep-ph]].
R. Boussarie, Y. Hatta, L. Szymanowski, and S. Wallon, “Probing the Sivers function with an unpolarized target: GTMD distributions
and the Odderons,” Phys. Rev. Lett. 124, 172501 (2020) doi:10.1103/PhysRevLett.124.172501 [arXiv:1912.08182 [hep-ph]].
Y. Hatta, M. Strikman, J. Xu, and F. Yuan, “Sub-threshold J/Ψ and Υ production in γA collisions,” Phys. Lett. B 803, 135321 (2020)
doi:10.1016/j.physletb.2020.135321 [arXiv:1911.11706 [hep-ph]].
S. Benic, Y. Hatta, H. N. Li, and D. J. Yang, “Single-spin asymmetries at two loops,” Phys. Rev. D 100, 094027 (2019)
doi:10.1103/PhysRevD.100.094027 [arXiv:1909.10684 [hep-ph]].
Y. Hatta, N. Mueller, T. Ueda, and F. Yuan, Phys. Lett. B 802, 135211 (2020) doi:10.1016/j.physletb.2020.135211 [arXiv:1907.09491[hep-ph]].
Y. Hatta and X. Yao, “QCD evolution of the orbital angular momentum of quarks and gluons: Genuine twist-three part,” Phys. Lett. B
798, 134941 (2019) doi:10.1016/j.physletb.2019.134941 [arXiv:1906.07744 [hep-ph]].
Y. Hatta, A. Rajan, and D. L. Yang, “Near threshold J/Ψ and Υ photoproduction at JLab and RHIC,” Phys. Rev. D 100, 014032 (2019)
doi:10.1103/PhysRevD.100.014032 [arXiv:1906.00894 [hep-ph]].
R. Boussarie, Y. Hatta, and F. Yuan, “Proton spin structure at small-x,” Phys. Lett. B 797, 134817 (2019) doi:10.1016/j.physletb.2019.134817[arXiv:1904.02693 [hep-ph]].
X. Yao, Y. Hagiwara, and Y. Hatta, “Computing the gluon Sivers function at small-x,” Phys. Lett. B 790, 361–366 (2019)
doi:10.1016/j.physletb.2019.01.029 [arXiv:1812.03959 [hep-ph]].
S. Benić and Y. Hatta, “Single spin asymmetry in forward pA collisions: Phenomenology at RHIC,” Phys. Rev. D 99, 094012 (2019)
doi:10.1103/PhysRevD.99.094012 [arXiv:1811.10589 [hep-ph]].
B. Schenke, C. Shen, and P. Tribedy, “Running the gamut of high energy nuclear collisions,” [arXiv:2005.14682 [nucl-th]].
A. Czajka, S. Hauksson, C. Shen, S. Jeon, and C. Gale, “Eﬀects of the mean field on fluid dynamics in the relaxation time approximation,”[arXiv:2004.11920 [nucl-th]].
B. Schenke, C. Shen, and D. Teaney, “Transverse momentum fluctuations and their correlation with elliptic flow in nuclear collision,”[arXiv:2004.00690 [nucl-th]].
C. Shen and S. Alzhrani, “A collision geometry-based 3D initial condition for relativistic heavy-ion collisions,” [arXiv:2003.05852 [nuclth]].
C. Gale, J. F. Paquet, B. Schenke, and C. Shen, “Probing early-time dynamics and quark-gluon plasma transport properties with photons
and hadrons,” [arXiv:2002.05191 [hep-ph]].
J. F. Paquet et al. [JETSCAPE], “Revisiting Bayesian constraints on the transport coeﬃcients of QCD,” [arXiv:2002.05337 [nucl-th]].
A. Monnai, B. Schenke, and C. Shen, “QCD equation of state at finite densities for nuclear collisions,” [arXiv:2002.02661 [nucl-th]].
C. Shen, “Studying QGP with flow: A theory overview,” [arXiv:2001.11858 [nucl-th]].
B. Schenke, C. Shen, and P. Tribedy, “Bulk properties and multi-particle correlations in large and small systems,” [arXiv:2001.09949[nucl-th]].
Y. Tachibana, C. Shen, and A. Majumder, “Bulk medium evolution has considerable eﬀects on jet observables!,” [arXiv:2001.08321[nucl-th]].
A. Kumar, A. Majumder, and C. Shen, “Energy and scale dependence of q̂ and the “JET puzzle”,” Phys. Rev. C 101, 034908 (2020)
doi:10.1103/PhysRevC.101.034908 [arXiv:1909.03178 [nucl-th]].
B. Schenke, C. Shen, and P. Tribedy, “Hybrid Color Glass Condensate and hydrodynamic description of the Relativistic Heavy Ion
Collider small system scan,” Phys. Lett. B 803, 135322 (2020) doi:10.1016/j.physletb.2020.135322 [arXiv:1908.06212 [nucl-th]].
G. Vujanovic, J. F. Paquet, C. Shen, G. S. Denicol, S. Jeon, C. Gale, and U. Heinz, “Exploring the influence of bulk viscosity of QCD on
dilepton tomography,” Phys. Rev. C 101, 044904 (2020) doi:10.1103/PhysRevC.101.044904 [arXiv:1903.05078 [nucl-th]].
A. Monnai, B. Schenke, and C. Shen, “Equation of state at finite densities for QCD matter in nuclear collisions,” Phys. Rev. C 100, 024907(2019) doi:10.1103/PhysRevC.100.024907 [arXiv:1902.05095 [nucl-th]].
A. Majumder, S. Cao, C. Shen, and G. Y. Qin, “Eﬀects of drag induced radiation and multi-stage evolution on heavy quark energy loss,”
PoS HardProbes2018, 130 (2019) doi:10.22323/1.345.0130 [arXiv:1902.02217 [nucl-th]].
C. Gale, S. Jeon, S. Mcdonald, J. F. Paquet, and C. Shen, “Centrality dependence of the direct photonmultiplicity in heavy ion collisions,”
PoS HardProbes2018, 178 (2019) doi:10.22323/1.345.0178 [arXiv:1901.07019 [nucl-th]].
B. Schenke, C. Shen, and P. Tribedy, “Multi-particle and charge-dependent azimuthal correlations in heavy-ion collisions at the Relativistic
Heavy-Ion Collider,” Phys. Rev. C 99, 044908 (2019) doi:10.1103/PhysRevC.99.044908 [arXiv:1901.04378 [nucl-th]].
√C. Gale, S. Jeon, S. McDonald, J. F. Paquet, and C. Shen, “Photon radiation from heavy-ion collisions in the sNN = 19–200 GeV
regime,” Nucl. Phys. A 982, 767–770 (2019) doi:10.1016/j.nuclphysa.2018.08.005 [arXiv:1807.09326 [nucl-th]].

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M. Singh, C. Shen, S. McDonald, S. Jeon, and C. Gale, “Hydrodynamic fluctuations in relativistic heavy-ion collisions,” Nucl. Phys. A
982, 319–322 (2019) doi:10.1016/j.nuclphysa.2018.10.061 [arXiv:1807.05451 [nucl-th]].
C. Shen and B. Schenke, “Dynamical initialization and hydrodynamic modeling of relativistic heavy-ion collisions,” Nucl. Phys. A 982,
411–414 (2019) doi:10.1016/j.nuclphysa.2018.08.007 [arXiv:1807.05141 [nucl-th]].
B. Schenke, C. Shen, and P. Tribedy, “Features of the IP-Glasma,” Nucl. Phys. A 982, 435–438 (2019) doi:10.1016/j.nuclphysa.2018.08.015[arXiv:1807.05205 [nucl-th]].
S. Ryu, S. McDonald, C. Shen, S. Jeon, and C. Gale, “Eﬀects of hadronic rescattering in mini-jet production and energy loss at the LHC,”PoS High-pT2017, 014 (2019) doi:10.22323/1.320.0014
S. Cao, A. Majumder, G. Y. Qin, and C. Shen, “Drag induced radiation and multi-stage eﬀects in heavy-flavor energy loss,” Phys. Lett.
B 793, 433–439 (2019) doi:10.1016/j.physletb.2019.05.020 [arXiv:1711.09053 [nucl-th]].
B. Chakraborty, M. Honda, T. Izubuchi, Y. Kikuchi, and A. Tomiya, “Digital quantum simulation of the Schwinger model with topologicalterm via adiabatic state preparation,” [arXiv:2001.00485 [hep-lat]].
K. Kashiwa, Y. Kikuchi, and A. Tomiya, “Phase transition encoded in neural network,” PTEP 2019, 083A04 (2019)
doi:10.1093/ptep/ptz082 [arXiv:1812.01522 [cond-mat.dis-nn]].
R. Kobayashi, K. Shiozaki, Y. Kikuchi, and S. Ryu, “Lieb-Schultz-Mattis type theorem with higher-form symmetry and the quantum
dimer models,” Phys. Rev. B 99, 014402 (2019) doi:10.1103/PhysRevB.99.014402 [arXiv:1805.05367 [cond-mat.stat-mech]].
W. Dekens, J. de Vries, K. Fuyuto, E. Mereghetti, and G. Zhou, “Sterile neutrinos and neutrinoless double beta decay in eﬀective field
theory,” J. High Energy Phys. 06, 097 (2020) doi:10.1007/JHEP06(2020)097 [arXiv:2002.07182 [hep-ph]].
J. de Vries, E. Epelbaum, L. Girlanda, A. Gnech, E. Mereghetti, and M. Viviani, “Parity- and time-reversal-violating nuclear forces,”[arXiv:2001.09050 [nucl-th]].
V. Cirigliano, W. Dekens, J. De Vries, M. Graesser, E. Mereghetti, S. Pastore, M. Piarulli, U. Van Kolck, and R. Wiringa, “Renormalized
approach to neutrinoless double- β decay,” Phys. Rev. C 100, 055504 (2019) doi:10.1103/PhysRevC.100.055504 [arXiv:1907.11254[nucl-th]].
J. de Vries, G. Falcioni, F. Herzog, and B. Ruijl, “Two- and three-loop anomalous dimensions of Weinberg’s dimension-six CP-odd
gluonic operator,” [arXiv:1907.04923 [hep-ph]].
V. Cirigliano, A. Crivellin, W. Dekens, J. de Vries, M. Hoferichter, and E. Mereghetti, “CP violation in higgs-gauge interactions: fromtabletop experiments to the LHC,” Phys. Rev. Lett. 123, 051801 (2019) doi:10.1103/PhysRevLett.123.051801 [arXiv:1903.03625 [hepph]].
F. Oosterhof, B. Long, J. de Vries, R. Timmermans, and U. van Kolck, Phys. Rev. Lett. 122, 172501 (2019) doi:10.1103/
PhysRevLett.122.172501 [arXiv:1902.05342 [hep-ph]].
J. Dragos, T. Luu, A. Shindler, J. de Vries, and A. Yousif, “Confirming the existence of the strong CP problem in lattice QCD with thegradient flow,” [arXiv:1902.03254 [hep-lat]].
J. De Vries, M. Postma, and J. van de Vis, “The role of leptons in electroweak baryogenesis,” J. High Energy Phys. 04, 024 (2019)
doi:10.1007/JHEP04(2019)024 [arXiv:1811.11104 [hep-ph]].
J. Kim, J. Dragos, A. Shindler, T. Luu, and J. de Vries, “Towards a determination of the nucleon EDM from the quark chromo-EDM
operator with the gradient flow,” PoS LATTICE2018, 260 (2019) doi:10.22323/1.334.0260 [arXiv:1810.10301 [hep-lat]].
J. de Vries, P. Draper, K. Fuyuto, J. Kozaczuk, and D. Sutherland, “Indirect signs of the peccei-quinn mechanism,” Phys. Rev. D 99,
015042 (2019) doi:10.1103/PhysRevD.99.015042 [arXiv:1809.10143 [hep-ph]].
W. Dekens, J. de Vries, M. Jung, and K. Vos, “The phenomenology of electric dipole moments in models of scalar leptoquarks,” J. HighEnergy Phys. 01, 069 (2019) doi:10.1007/JHEP01(2019)069 [arXiv:1809.09114 [hep-ph]].
J. Dragos, T. Luu, A. Shindler, J. de Vries, and A. Yousif, “Improvements to nucleon matrix elements within a θ vacuum from Lattice
QCD,” PoS LATTICE2018, 259 (2019) doi:10.22323/1.334.0259 [arXiv:1809.03487 [hep-lat]].
A. Connelly, G. Johnson, F. Rennecke, and V. Skokov, “Universal location of the Yang-Lee edge singularity in O(N) theories,”[arXiv:2006.12541 [cond-mat.stat-mech]].
A. Connelly, G. Johnson, S. Mukherjee, and V. Skokov, “Universality driven analytic structure of QCD crossover: radius of convergenceand QCD critical point,” [arXiv:2004.05095 [hep-ph]].
C. P. Korthals Altes, H. Nishimura, R. D. Pisarski, and V. V. Skokov, “Free energy of a holonomous plasma,” Phys. Rev. D 101, 094025(2020) doi:10.1103/PhysRevD.101.094025 [arXiv:2002.00968 [hep-ph]].
A. Dumitru, V. Skokov, and T. Stebel, “Subfemtometer scale color charge correlations in the proton,” Phys. Rev. D 101, 054004 (2020)
doi:10.1103/PhysRevD.101.054004 [arXiv:2001.04516 [hep-ph]].
H. Duan, C. Akkaya, A. Kovner, and V. V. Skokov, “Entanglement, partial set of measurements, and diagonality of the density matrix inthe parton model,” Phys. Rev. D 101, 036017 (2020) doi:10.1103/PhysRevD.101.036017 [arXiv:2001.01726 [hep-ph]].
C. P. Korthals Altes, H. Nishimura, R. D. Pisarski, and V. V. Skokov, “Conundrum for the free energy of a holonomous gluonic plasma at
cubic order,” Phys. Lett. B 803, 135336 (2020) doi:10.1016/j.physletb.2020.135336 [arXiv:1911.10209 [hep-th]].
S. Schlichting and V. Skokov, “Saturation corrections to dilute-dense particle production and azimuthal correlations in the Color Glass
Condensate,” Phys. Lett. B 806, 135511 (2020) doi:10.1016/j.physletb.2020.135511 [arXiv:1910.12496 [hep-ph]].
S. Mukherjee and V. Skokov, “Universality driven analytic structure of QCD crossover: radius of convergence in baryon chemical potential,” [arXiv:1909.04639 [hep-ph]].
V. Skokov, “Measuring the Weizsäcker-Williams distribution of linearly polarized gluons at an electron-ion collider through dijet azimuthal asymmetries,” PoS DIS2019, 256 (2019) doi:10.22323/1.352.0256 [arXiv:1907.10334 [hep-ph]].

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M. Martinez, T. Schäfer, and V. Skokov, “Critical behavior of the bulk viscosity in QCD,” Phys. Rev. D 100, 074017 (2019)
doi:10.1103/PhysRevD.100.074017 [arXiv:1906.11306 [hep-ph]].
R. D. Pisarski, V. V. Skokov, and A. Tsvelik, “A Pedagogical Introduction to the Lifshitz Regime,” Universe 5, 48 (2019)
doi:10.3390/universe5020048
M. Mace, V. V. Skokov, P. Tribedy, and R. Venugopalan, “Initial state description of azimuthally collimated long range correlations inultrarelativistic light-heavy ion collisions,” [arXiv:1901.10506 [hep-ph]].
N. Armesto, F. Dominguez, A. Kovner, M. Lublinsky, and V. Skokov, “The Color Glass Condensate density matrix: Lindblad evolution,
entanglement entropy and Wigner functional,” J. High Energy Phys. 05, 025 (2019) doi:10.1007/JHEP05(2019)025 [arXiv:1901.08080[hep-ph]].
H. Nishimura, C. Korthals-Altes, R. D. Pisarski, and V. Skokov, “Thermal eﬀective potential for the Polyakov loop to higher loop order,”PoS Confinement2018, 155 (2019) doi:10.22323/1.336.0155 [arXiv:1811.11736 [hep-th]].
A. Dumitru, V. Skokov, and T. Ullrich, “Measuring the Weizsäcker-Williams distribution of linearly polarized gluons at an electron-ion
collider through dijet azimuthal asymmetries,” Phys. Rev. C 99, 015204 (2019) doi:10.1103/PhysRevC.99.015204 [arXiv:1809.02615[hep-ph]].
K. Dusling, M. Mace, V. V. Skokov, P. Tribedy, and R. Venugopalan, “Multiparticle correlations and collectivity in small systems fromthe initial state,” Nucl. Phys. A 982, 495–498 (2019) doi:10.1016/j.nuclphysa.2018.09.051 [arXiv:1807.06032 [hep-ph]].
M. Mace, V. V. Skokov, P. Tribedy, and R. Venugopalan, “Systematics of azimuthal anisotropy harmonics in proton–nucleus collisions at
the LHC from the Color Glass Condensate,” Phys. Lett. B 788, 161–165 (2019) doi:10.1016/j.physletb.2018.09.064 [arXiv:1807.00825[hep-ph]].
M. Mace, V. V. Skokov, P. Tribedy, and R. Venugopalan, “Hierarchy of azimuthal anisotropy harmonics in collisions of small systems fromthe Color Glass Condensate,” Phys. Rev. Lett. 121, 052301 (2018) doi:10.1103/PhysRevLett.121.052301 [arXiv:1805.09342 [hep-ph]].
R. D. Pisarski, V. V. Skokov, and A. M. Tsvelik, “Fluctuations in cool quark matter and the phase diagram of Quantum Chromodynamics,”
Phys. Rev. D 99, 074025 (2019) doi:10.1103/PhysRevD.99.074025 [arXiv:1801.08156 [hep-ph]].
A. Dumitru, F. Gelis, T. Lappi, and Y. Mehtar-Tani, “Summary of week VII,” doi:10.1142/9789811214950 0057
Y. Mehtar-Tani, A. Soto-Ontoso, and K. Tywoniuk, “Tagging boosted hadronic objects with dynamical grooming,” [arXiv:2005.07584[hep-ph]].
J. Barata and Y. Mehtar-Tani, “Improved opacity expansion at NNLO for medium induced gluon radiation,” [arXiv:2004.02323 [hep-ph]].
Y. Mehtar-Tani, “Improved opacity expansion for medium-induced parton splitting,” [arXiv:2003.02884 [hep-ph]].
C. A. Aidala, E. Aschenauer, F. Aslan, A. Bacchetta, I. Balitsky, S. Benic, S. Bhattacharya, M. Boglione, M. Burkardt, J. Cammarota,
G. A. Chirilli, C. Cocuzza, A. Courtoy, D. de Florian, P. Di Nezza, A. Dumitru, S. Fucini, K. Fukushima, Y. Furletova, L. Gamberg,
O. Garcia-Montero, F. Gelis, V. Guzey, Y. Hatta, F. Hautmann, T. J. Hobbs, T. Horn, E. Iancu, S. Joosten, Z. B. Kang, R. Kishore,
Y. V. Kovchegov, P. Kroll, K. Kumerički, K. Kutak, T. Lappi, H. W. Lin, X. Liu, S. Liuti, C. Lorcé, H. Mäntysaari, C. Marquet,
Y. Makris, K. A. Mamo, Y. Mehtar-Tani, A. Metz, Z. E. Meziani, G. A. Miller, J. Miller, A. Mukherjee, P. M. Nadolsky, F. I. Olness,
B. Pasquini, B. Pire, C. Pisano, D. Pitonyak, M. V. Polyakov, A. Prokudin, J. W. Qiu, M. Radici, A. Rajan, S. Rajesh, M. Rinaldi,
K. Roy, C. Royon, N. Sato, M. Schlegel, G. Schnell, P. Schweitzer, S. Scopetta, R. Seidl, K. Semenov-Tian-Shansky, A. Signori,
D. Sokhan, A. M. Stasto, L. Szymanowski, A. Tarasov, D. Triantafyllopoulos, T. Ullrich, R. Venugopalan, I. Vitev, W. Vogelsang,
A. Vossen, B. T. Wang, S. Wallon, K. Watanabe, C. Weiss, B. W. Xiao, H. U. Yee, and Y. Zhao, “Probing nucleons and nuclei in highenergy collisions,” doi:10.1142/11684 [arXiv:2002.12333 [hep-ph]].
R. Boussarie and Y. Mehtar-Tani, “On gauge invariance of transverse momentum dependent distributions at small x,” [arXiv:2001.06449[hep-ph]].
Y. Mehtar-Tani, A. Soto-Ontoso, and K. Tywoniuk, “Dynamical grooming of QCD jets,” Phys. Rev. D 101, 034004 (2020) doi:10.1103/
PhysRevD.101.034004 [arXiv:1911.00375 [hep-ph]].
Y. Mehtar-Tani and K. Tywoniuk, “Improved opacity expansion for medium-induced parton splitting,” [arXiv:1910.02032 [hep-ph]].
Y. Mehtar-Tani, A. Soto-Ontoso, and M. Verweij, “Background estimator for jet studies in p + p and A + A collisions,” Phys. Rev. D 100,
114023 (2019) doi:10.1103/PhysRevD.100.114023 [arXiv:1904.12815 [hep-ph]].
Y. Mehtar-Tani, “Gluon bremsstrahlung in finite media beyond multiple soft scattering approximation,” J. High Energy Phys. 07, 057(2019) doi:10.1007/JHEP07(2019)057 [arXiv:1903.00506 [hep-ph]].
Y. Mehtar-Tani and K. Tywoniuk, “Higher-order corrections to jet quenching,” PoS HardProbes2018, 096 (2019) doi:10.22323/1.345.0096[arXiv:1903.01302 [hep-ph]].
K. Tywoniuk and Y. Mehtar-Tani, “Toward a unified description of jet and medium scales in heavy-ion collisions,” Nucl. Phys. A 982,
631–634 (2019) doi:10.1016/j.nuclphysa.2018.12.003
H. A. Andrews, L. Apolinario, R. A. Bertens, C. Bierlich, M. Cacciari, Y. Chen, Y. T. Chien, L. C. Mendez, M. Deak, D. d’Enterria,
F. Dominguez, P. C. Harris, K. Kutak, Y. J. Lee, Y. Mehtar-Tani, J. Mulligan, M. Nguyen, C. Ning-Bo, D. Perepelitsa, G. Salam,M. Spousta, J. G. Milhano, K. Tywoniuk, M. Van Leeuwen, M. Verweij, V. Vila, U. A. Wiedemann, and K. C. Zapp, “Novel tools andobservables for jet physics in heavy-ion collisions,” J. Phys. G 47, 065102 (2020) doi:10.1088/1361-6471/ab7cbc [arXiv:1808.03689[hep-ph]].

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Subnuclear System Research Division
RIKEN BNL Research Center
Experimental Group
1. Abstract

RIKEN BNL Research Center (RBRC) Experimental Group studies the strong interactions (QCD) using RHIC accelerator at
Brookhaven National Laboratory, the world first heavy ion collider and polarized p + p collider. We have three major activities: Spin
Physics at RHIC, Heavy ion physics at RHIC, and detector upgrades of PHENIX experiment at RHIC.
We study the spin structure of the proton using the polarized proton-proton collisions at RHIC. This program has been promoted
by RIKEN’s leadership. The first focus of the research is to measure the gluon spin contribution to the proton spin. Recent resultsfrom PHENIX π0 measurement and STAR jet measurement has shown that gluons in the proton carry about 30% of the proton spin.
This is a major milestone of RHIC spin program. The second goal of the spin program is to measure the polarization of anti-quarks inthe proton using W → e and W → µ decays. The results of W → e measurement was published in 2016. The final results of W → µ
was published in 2018.
The aim of Heavy ion physics at RHIC is to re-create Quark Gluon Plasma (QGP), the state of Universe just after the Big Bang.
Two important discoveries, jet quenching eﬀect and strong elliptic flows, have established that new state of dense matter is indeed
produced in heavy ion collisions at RHIC. We are now studying the property of the matter. Recently, we have measured direct photons
in Au + Au collisions for 1 < pT < 3 GeV/c, where thermal radiation from hot QGP is expected to dominate. The comparison between
the data and theory calculations indicates that the initial temperature of 300 MeV to 600 MeV is achieved. These values are well above
the transition temperature to QGP, which is calculated to be approximately 160 MeV by lattice QCD calculations.
We had major roles in detector upgrades of PHENIX experiment, namely, the silicon vertex tracker (VTX) and muon trigger
upgrades. Both of the upgrade is now complete. The VTX is the main device to measure heavy quark (charm and bottom) production
and the muon trigger is essential for W → µ measurement. The results from the first run with VTX detector in 2011 was published.
The results show that electrons from bottom quark decay is strongly suppressed at high pT , but the suppression is weaker than that ofcharm decay electron for 3 < pT < 4 GeV/c. We have recorded 10 times as much Au + Au collisions data in each of the 2014 run and2016 run. The large dataset will produce definitive results on heavy quark production at RHIC.
PHENIX completed its data taking in 2016. We are now working on R&D of intermediate silicon tracker INTT for sPHENIX, a
new experiment at RHIC that will be installed in the PHENIX IR.

2. Major Research Subjects(1) Experimental Studies of the Spin Structure of the Nucleon(2) Study of Quark-Gluon Plasma at RHIC
(3) PHENIX detector upgrades

3. Summary of Research Activity

We study the strong interactions (QCD) using the RHIC accelerator at Brookhaven National Laboratory, the world first heavy ion
collider and polarized p + p collider. We have three major activities: Spin Physics at RHIC, Heavy ion physics at RHIC, and detector
upgrades of PHENIX experiment. From 2015, Y. Akiba (Experimental Group Leader) is the Spokesperson of PHENIX experiment.
(1) Experimental study of spin structure of proton using RHIC polarized proton collider
How is the spin of proton formed with 3 quarks and gluons? This is a very fundamental question in Quantum Chromodynamics(QCD), the theory of the strong nuclear forces. The RHIC Spin Project has been established as an international collaboration between
RIKEN and Brookhaven National Laboratory (BNL) to solve this problem by colliding two polarized protons for the first time inhistory. This project also has extended the physics capabilities of RHIC.
The first goal of the Spin Physics program at RHIC is to determine the gluon contribution to proton spin. It is known that the spinof quark accounts for only 25% of proton spin. The remaining 75% should be carried either by the spin of gluons or the orbital angularmomentum of quarks and gluons. One of the main goals of the RHIC spin program has been to determine the gluon spin contribution.
Before the start of RHIC, there was little experimental constraint on the gluon polarization, ∆G.
PHENIX measures the double helicity asymmetry (ALL ) of π0 production to determine the gluon polarization. Our most recent
publication of π0 ALL measurement at 510 GeV shows non-zero value of ALL , indicating that gluons in the proton is polarized. Global
analysis shows that approximately 30% of proton spin is carried by gluons.
RHIC achieved polarized p + p collisions at 500 GeV in 2009. The collision energy increased to 510 GeV in 2012 and 2013. The
main goal of these high energy p + p run is to measure anti-quark polarization via single spin asymmetry AL of the W production. We
upgraded the muon trigger system to measure W → µ decays in the forward direction. With the measurement of W → e and W → µ,we can cover a wide kinematic range in anti-quark polarization measurement. The 2013 run is the main spin run at 510 GeV. PHENIX
has recorded more than 150/pb of data in the run. The final results of the AL measurement in W → e channel in combined data of2011 to 2013 was published in 2016. The paper on the final results of W → µ was published in 2018. These high statistics results givestrong constraints on the polarization of anti-quarks in the proton.
RHIC has the first polarized proton nucleus collision run in 2015. In this run, we discovered a surprisingly large nuclear dependence of single spin asymmetry of very forward neutron. The paper of this discovery was published in Physical Review Letters.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Fig. 1. Single spin asymmetry AL of electrons from W and Z decays. The AL is sensitive to the polarization of anti-quarks in the proton. The curves and theshaded region show theoretical calculations based on various polarized parton distribution (PDF) sets. The mid-rapidity points were published in Phys.
Rev. D 93, 051103(R) (2016). The forward/backward points were published in Phys. Rev. D 98, 032007 (2018).

Fig. 2. Single spin asymmetry AN of very forward neutron in p + p, p + Al, and p + Au collision. Published in Phys. Rev. Lett. 120, 022001 (2018).

(2) Experimental study of Quark-Gluon Plasma using RHIC heavy-ion collider
The goal of high energy heavy ion physics at RHIC is study of QCD in extreme conditions i.e. at very high temperature and atvery high energy density. Experimental results from RHIC have established that dense partonic matter is formed in Au + Au collisions
at RHIC. The matter is very dense and opaque, and it has almost no viscosity and behaves like a perfect fluid. These conclusions areprimarily based on the following two discoveries:• Strong suppression of high transverse momentum hadrons in central Au + Au collisions (jet quenching)• Strong elliptic flow
These results are summarized in PHENIX White paper, which has approximately 2700 citations to date. The focus of the research inheavy ion physics at RHIC is now to investigate the properties of the matter. RBRC have played the leading roles in some of the mostimportant results from PHENIX in the study of the matter properties. These include (1) measurements of heavy quark production
from the single electrons from heavy flavor decay (2) measurements of J/Ψ production (3) measurements of di-electron continuumand (4) measurements of direct photons.
Our most important result is the measurement of direct photons for 1 < pT < 5 GeV/c in p + p and Au + Au through their internalconversion to e+ e− pairs. If the dense partonic matter formed at RHIC is thermalized, it should emit thermal photons. Observation ofthermal photon is direct evidence of early thermalization, and we can determine the initial temperature of the matter. It is predictedthat thermal photons from QGP phase is the dominant source of direct photons for 1 < pT < 3 GeV/c at the RHIC energy. We
measured the direct photon in this pT region from measurements of quasi-real virtual photons that decays into low-mass e+ e− pairs.
Strong enhancement of direct photon yield in Au + Au over the scaled p + p data has been observed. Several hydrodynamical models
can reproduce the central Au + A data within a factor of two. These models assume formation of a hot system with initial temperatureof T init = 300 MeV to 600 MeV. This is the first measurement of initial temperature of quark gluon plasma formed at RHIC. These- 378 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Fig. 3. Left: Cover of Nature Physics March 2019 issue featuring the PEHNIX article reporting strong evidence of small QGP droplent formation. Right: Dataof elliptic and triangular flow measured in p+Au, d+Au and 3 He+Au collisions.

Fig. 4. Preliminary results of the elliptic flow strength ν2 of single electrons from charm and bottom decays.

results are recently published in Physical Review Letters. Y. Akiba is the leading person of the analysis and the main author of thepaper. He received 2011 Nishina memorial Prize mainly based on this work.
PHENIX experiment measured the flow in small collision systems (p + Au, d + Au, and 3 He + Au), and observed strong flow in allof these systems. Theoretical models that assume formation of small QGP droplets best describe the data. These results are publishedin Nature Physics in 2019.
(3) Detector upgrade
The group had major roles in several PHENIX detector upgrades, namely, the silicon vertex tracker (VTX) and muon trigger
upgrades. VTX is a high precision charged particle tracker made of 4 layers of silicon detectors. It is jointly funded by RIKEN andthe US DOE. The inner two layers are silicon pixel detectors and the outer two layers are silicon strip detectors. Y. Akiba is the project
manager and A. Deshpande is the strip system manager. The VTX detector was completed in November 2010 and subsequently
installed in PHENIX. The detector started taking data in the 2011 run. With the new detector, we measure heavy quark (charm andbottom) production in p + p, A + A collisions to study the properties of quark-gluon plasma. The final result of the 2011 run was
published. The result show that single electrons from bottom quark decay is suppressed, but not as strong as that from charm decay
in low pT region (3 < pT < 4 GeV/c). This is the first measurement of suppression of bottom decay electrons at RHIC and the firstobservation that bottom suppression is smaller than charm. We have recorded 10 times as much Au + Au collisions data in eachof the 2014 run and 2016 run. The large dataset will produce definitive results on heavy quark production at RHIC. A preliminary
results on the elliptic flow strength ν2 of b → e and c → e has been presented in Quark Matter 2018 conference. The results ofbottom/charm ratios in p + p collisions at 200 GeV from the 2015 run was published (Phys. Rev. D99 092003 (2019)). A paper
reporting measurements of the nuclear suppression factor RAA of charm and bottom in Au+Au collisions from the 2014 data is inpreparation.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Fig. 5. Three ladder telescope made from INTT silicon tracker prototype. The prototype detector was tested in a beam test at FNAL in February 2018.

PHENIX completed its data taking in 2016. We are now working on R&D of intermediate silicon tracker INTT for sPHENIX, a
new experiment at RHIC that will be installed in the PHENIX IR. A three ladder telescope of INTT prototype modules was tested ina beam test at FNAL. The prototype detector worked very well during the test.

Members
Group Leader
Yasuyuki AKIBARBRC Researchers
Jan C. BERNAUER
Megan CONNORS
Yuji GOTO
Takashi HACHIYA
Itaru NAKAGAWA
Seidl RALF

Atsushi TAKETANI
Takahito TODOROKI
Marta VERWEIJ
Yasushi WATANABE
Satoshi YOKKAICHISpecial Temporary Research Scientist
Takashi ICHIHARA
Visiting Scientists
Stefan BATHE (Baruch College Univ. of New York)
Gaku MITSUKA (KEK)
Rachid NOUICER (BNL)

Masahiro OKAMURA (BNL)
Takao SAKAGUCHI (BNL)
Takashi SAKO (Univ. of Tokyo)

Student Trainees
Kai-Yu Cheng (National Central U)
Anthony Hodges (Georgia State U)
Lihan Liu (Vanderbilt U)

Xiao Rui (Purdue U)
Cheng-Wei Shih (National Central U)
Cheuk-Ping Wong (Georgia State U)

List of Publications & Presentations
Publications[Original papers]
C. Aidala et al., “Creation of quark-gluon plasma droplets with three distinct geometries,” Nature Physics 15, 214 (2019).
A. Adare et al., “Beam energy and centrality dependence of direct-photon emission from ultrarelativistic heavy-ion collisions,” Phys. Rev.
Lett. 123, 022301 (2019).
C. Aidala et al., “Nuclear dependence of the transverse single-spin asymmetry in the production of charged hadrons at forward rapidity√
in polarized p+p, p+Al, and p+Au collisions at sNN = 200 GeV,” Phys. Rev. Lett. 123, 122001 (2019).
A. Adare et al., “Multiparticle azimuthal correlations for extracting event-by-event elliptic and triangular flow in Au+Au collisions at√
sNN = 200 GeV,” Phys. Rev. C 99, 024903 (2019).
√
C. Aidala et al., “Nonpertuarbative transverse momentum broadening in dihedron angular correlations in sNN = 200 GeV proton-nucleus
collisions,” Phys. Rev. C 99 044912 (2019).
A. Adare et al., “Measurement of two-particle correlations with respect to second- and third- order event planes in Au+Au collisions at√
sNN = 200 GeV,” Phys. Rev. C 99, 5,054903 (2019).
√
C. Aidla et al., “Measurements of µµ pairs from open heavy flavor and Drell-Yan in p+p collisions at s = 200 GeV,” Phys. Rev. D 99,
072003 (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

C. Aidla et al., “Measurement of charm and bottom production from semileptonic hadron decays in p+p collisons at
Phys. Rev. D 99, 092003 (2019).

√

sNN = 200 GeV,”

Presentations[International conferences/workshops]
T. Hachiya (invited), “PHENIX heavy flavor highlights,” 8th International conference on new frontiers in physics (ICNFP 2019), Crete,
Greece, August 21–29, 2019.
M. Connors (invited), “PHENIX jighlights,” 28th International conference on ultrarelativistic nucleus-nucleus collisions (Quark Matter2019), Wuhan, China, November 4–9, 2019.
T. Todoroki (oral), “Quark flavor dependence of particle flow in nucleus-nucleus collisions measured by PHENIX,” 28th International
conference on ultrarelativistic nucleus-nucleus collisions (Quark Matter 2019), Wuhan, China, November 4–9, 2019.

AwardsMegan Connors, CAREER award from the National Science Foundation.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
RIKEN BNL Research Center
Computing Group
1. Abstract

The computing group founded in 2011 as a part of the RIKEN BNL Research Center established at Brookhaven National Laboratory in New York, USA, and dedicated to conduct researches and developments for large-scale physics computations important forparticle and nuclear physics. The group was forked from the RBRC Theory Group.
The main mission of the group is to provide important numerical information that is indispensable for theoretical interpretationof experimental data from the first principle theories of particle and nuclear physics. Their primary area of research is lattice quantum
chromodynamics (QCD), which describes the sub-atomic structures of hadrons, which allow us the ab-initio investigation for stronglyinteracting quantum field theories beyond perturbative analysis.
The RBRC group and its collaborators have emphasized the necessity and importance of precision calculations, which will precisely check the current understandings of nature, and will have a potential to find a physics beyond the current standard model offundamental physics. We have therefore adopted techniques that aim to control and reduce any systematic errors. This approach has
yielded many reliable results.
The areas of the major activities are R&D for high performance computers, developments for computing algorithms, and researches of particle, nuclear, and lattice theories. Since the inception of RBRC, many breakthroughs and pioneering works has carriedout in computational forefronts. These are the use of the domain-wall fermions, which preserve chiral symmetry, a key symmetry forunderstanding nature of particle nuclear physics, the three generations of QCD devoted supercomputers, pioneering works for QCD
calculation for Cabibbo-Kobayashi-Maskawa theory, QCD + QED simulation for isospin breaking, novel algorithm for error reduction
in general lattice calculation. Now the chiral quark simulation is performed at the physical up, down quark mass, the precision formany basic quantities reached to accuracy of sub-percent, and the group is aiming for further important and challenging calculations,such as the full and complete calculation of CP violating K → ππ decay and ε′ /ε, or hadronic contributions to muon’s anomalous
magnetic moment g − 2. Another focus area is the nucleon’s shape, structures, and the motion of quarks and gluon inside nucleon
called parton distribution, which provide theoretical guidance to physics for sPHENIX and future Electron Ion Collider (EIC), Hyper
Kamiokande, DUNE, or the origin of the current matter rich universe (rather than anti-matter). Towards finite density QCD, they also
explore Quantum Computing to overcome the sign problem.

2. Major Research Subjects(1) Search for new law of physics through tests for Standard Model of particle and nuclear physics, especially in the frameworkof the Cabibbo-Kobayashi-Maskawa (CKM), hadronic contributions to the muon’s anomalous magnetic moment (g − 2) for
FNAL and J-PARC’s experiments, as well as B physics at Belle II and LHCb.
(2) Nuclear Physics and dynamics of QCD or related theories, including study for the structures of nucleons related to physics
for Electron Ion Collider (EIC or eRHIC), Hyper Kamiokande, T2K, DUNE.
(3) Theoretical and algorithmic development for lattice field theories, QCD machine (co-)design and code optimization.

3. Summary of Research Activity

In 2011, QCD with Chiral Quarks (QCDCQ), a third-generation lattice QCD computer that is a pre-commercial version of IBM’s
Blue Gene/Q, was installed as an in-house computing resource at the RBRC. The computer was developed by collaboration among
RBRC, Columbia University, the University of Edinburgh, and IBM. Two racks of QCDCQ having a peak computing power of 2 × 200
TFLOPS are in operation at the RBRC. In addition to the RBRC machine, one rack of QCDCQ is owned by BNL for wider use forscientific computing. In 2013, 1/2 rack of Blue Gene/Q is also installed by US-wide lattice QCD collaboration, USQCD. The group
has also used the IBM Blue Gene supercomputers located at Argonne National Laboratory and BNL (NY Blue), and Hokusai and
RICC, the super computers at RIKEN (Japan), Fermi National Accelerator Laboratory, the Jeﬀerson Lab, and others. From 2016, thegroup started to use the institutional cluster both GPU and Intel Knight Landing (KNL) clusters installed at BNL and University ofTokyo extensively.
Such computing power enables the group to perform precise calculations using up, down, and strange quark flavors with proper
handling of the important symmetry, called chiral symmetry, that quarks have. The group and its collaborators carried out the first
calculation for the direct breaking of CP (Charge Parity) symmetry in the hadronic K meson decay (K → ππ) amplitudes, ε′ /ε, which
provide a new information to CKM paradigm and its beyond. They also provide the hadronic contribution in muon’s anomalous magnetic moment (g − 2)µ . These calculation for ε′ /ε, hadronic light-by-light of (g − 2), are long waited calculation in theoretical physics
delivered for the first time by the group. The K → ππ result in terms of ε′ /ε currently has a large error, and deviates from experimental
results by 2.1 σ. To collect more information to decide whether this deviation is from the unknown new physics or not, the group continues to improve the calculation in various way to reduce their error. Hadronic light-by-light contribution to (g − 2)µ is improved bymore than two order of magnitudes compared to our previous results. As of 2019 summer, their calculation is among the most precise
determination for the g − 2 hadronic vacuum polarization (HVP), and only one calculation in the world for the hadronic light-by-light(HLbL) contribution at physical point. These (g − 2)µ calculations provide the first principle theoretical prediction for on-going newexperiment at FNAL and also for the planned experiment at J-PARC. Other projects including flavor physics in the framework of the
CKM theory for kaons and B mesons that include the new calculation of b-baryon decay, Λb → p; the electromagnetic properties- 382 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

of hadrons; the proton’s and neutron’s form factors and structure function including electric dipole moments; proton decay; nucleon
form factors, which are related to the proton spin problem or neutrino-nucleon interaction; Neutron-antineutron oscillations; inclusive
hadronic decay of τ leptons; nonperturbative studies for beyond standard model such composite Higgs or dark matter models fromstrong strongly interacting gauge theories; a few-body nuclear physics and their electromagnetic properties; QCD thermodynamics
in finite temperature/density systems such as those produced in heavy-ion collisions at the Relativistic Heavy Ion Collider; Quantum
Information, Quantum Computing; and applications of machine learning in field theories.
The RBRC group and its collaborators have emphasized the necessity and importance of precision calculations, which will provide
stringent checks for the current understandings of nature, and will have a potential to find physics beyond the current standard modelof fundamental physics. We have therefore adopted techniques that aim to control and reduce any systematic errors. This approach
has yielded many reliable results, many of basic quantities are now computed within sub-percent accuracies.
The group also delivers several algorithmic breakthroughs, which speed up generic lattice gauge theory computation. These novel
technique divides the whole calculation into frequent approximated calculations, and infrequent expensive and accurate calculation
using lattice symmetries called All Mode Averaging (AMA), or a compression for memory needs by exploiting the local-coherenceof QCD dynamics. Together with another formalism, zMobius fermion, which approximate chiral lattice quark action eﬃciently, thetypical calculation is now improved by a couple of orders of magnitudes, and more than an order of magnitude less memory needs
compared to the traditional methods. RBRC group and its collaborators also provide very eﬃcient and generic code optimized to thestate-of-arts CPU or GPU, and also improve how to eﬃciently generate QCD ensemble.

Extrapolation to continuum and infinite volume (prelim)30

48I-64I
24D
32D
48D
32Dfine25aµ × 1010

c1
1−(1 − c2 a2)(m µL)2

20
15
10

(6)

0

48I-64I
24D
32D
32Dfine−2−4aµ × 1010

F2(a, L) = F2



13/20

−6
−8
−10

5

−12

0

−14
0

0.05

0.1

0.15

0.2

0

1/(mµ L)2

0.05

0.1

0.15

0.2

1/(mµ L)2

Connected diagrams

Disconnected diagrams± 0.28) × 10−10
acHLbL = (28.46 ± 3.66
adHLbL= (−12.39 ± 2.09stat ± 1.63sys,a2) × 10−10
µ

(7)
(8)

aHLbL
= (16.06 ± 3.90stat ± 1.91sys,a2) × 10−10µ(9)Fig. 1. The bottom plots are Hadronic
Light-by-Light (HLbL) contributionsstat
to muon anomalous
magnetic
moment shown at top diagram.
2
sys,a
µ

• Plenary talk given at LATTICE 2018. We are still accumulating more statistics.

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0.5
0

JAM
xFitter
FNAL
ASV

RIKEN Accel.
0 Prog. Rep. 53

0.2

0.4

0.6

Ⅵ. RNC ACTIVITIES

0.8

1

x
4
0.4

µ = 3.2 GeV

3.5

fv⇡ (x)2.5
20.3
xfv⇡ (x)

3

and
to 2
was
futu

0.2

0.1

1.5
0

0

0.2

0.4

0.8

1

x

1
continuum est.
JAM18
0.5
xFitter
FNAL
ASV
0
0
0.2

0.6

0.4

0.6

0.8

1

x

FIG. 29.
Our determinations of valence PDF of pion,⇡fv (x, µ), at factorization scale µ = 3.2 GeV. (Top panel)
The PDF determination from a = 0.04 fm data (red) andMembersa = 0.04 fm data (blue). (Bottom panel) Our estimate ofGroup Leader
PDF in the continuum limit (blue). In both top and bottom
Taku IZUBUCHI
panels, the darker inner band includes only the statistical erSpecial Postdoctoral Researchersror.
The lighter outer band includes
both statistical error as
Akio
TOMIYA
Enrico RINALDI
well as the systematic errors. Our estimates are compared
RBRC Researcherswith AOKIthe(RIKEN
FNAL
E-0615
estimate[37](greensymbols),
ASV
Yasumichi
BNL Fellow,
KEK)
SergeySYRITSYN(RHIC Physics
Fellow)
Ethan NEIL (RHIC Physics Fellow)
Luchang JIN (RHIC Physics Fellow)
estimate[27](greenStefanMEINEL (RHIC
Physics
Fellow) dashed line), JAM estimate [70] (blackband) and xFitter analysis [75] (purple line). Insets: the same
Visiting Scientists⇡
dataBLUM
are(Univ.
replotted
xf(BNL)
Thomasof Connecticut) as the traditional
Meifeng LINv (x) versus x.

Fig. 2. Parton Distribution of pion as function of momentum fraction of valence quark, x, at factorization scale 3.2 GeV compred to phenomenological andexperimental determinations. From arXiv:2007.06590

Chulwoo JUNG (BNL)
Shigemi OHTA (KEK)
Tomomi ISHIKAWA (Shanghai Jiao-Tong Univ.)
Christoph LEHNER (BNL)

Robert MAWHINNEY (Columbia Univ.)
Hiroshi OKI (Nara Women’s Univ.)
Christopher KELLY (Columbia Univ.)

Finally, we compare our PDF determinations with
384 other global fit analysis in - thesummary plot in Fig. 29.
Along with our determinations of valence PDFs at the

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Original papers]
C. Y. Seng, X. Feng, M. Gorchtein, and L. C. Jin, “Joint lattice QCD–dispersion theory analysis confirms the quark-mixing top-row
unitarity deficit,” Phys. Rev. D 101, 111301 (2020). doi:10.1103/PhysRevD.101.111301 [arXiv:2003.11264 [hep-ph]].
X. Feng, M. Gorchtein, L. C. Jin, P. X. Ma, and C. Y. Seng, “First-principles calculation of electroweak box diagrams from lattice QCD,”
Phys. Rev. Lett. 124, 192002 (2020). doi:10.1103/PhysRevLett.124.192002 [arXiv:2003.09798 [hep-lat]].
T. Blum, N. Christ, M. Hayakawa, T. Izubuchi, L. Jin, C. Jung, and C. Lehner, “Hadronic light-by-light scattering contribution to themuon anomalous magnetic moment from lattice QCD,” Phys. Rev. Lett. 124, 132002 (2020). doi:10.1103/PhysRevLett.124.132002[arXiv:1911.08123 [hep-lat]].
X. Feng, Y. Fu, and L. C. Jin, “Lattice QCD calculation of the pion charge radius using a model-independent method,” Phys. Rev. D 101,
051502 (2020). doi:10.1103/PhysRevD.101.051502 [arXiv:1911.04064 [hep-lat]].
X. Y. Tuo, X. Feng, and L. C. Jin, “Long-distance contributions to neutrinoless double beta decay π− → π+ ee,” Phys. Rev. D 100, 094511(2019). doi:10.1103/PhysRevD.100.094511 [arXiv:1909.13525 [hep-lat]].
G. Rendon, S. Meinel et al., “I = 1/2 S -wave and P-wave Kπ scattering and the κ and K ∗ resonances from lattice QCD,” arXiv:2006.14035[hep-lat]
T. Blake, S. Meinel, and D. van Dyk. “Bayesian analysis of b → sµ+ µ− Wilson coeﬃcients using the full angular distribution ofΛb → Λ(→ p π− )µ+ µ− Decays,” Phys. Rev. D 101, 035023 (2020).
R. Larsen, S. Meinel, S. Mukherjee, and P. Petreczky, “Excited bottomonia in quark-gluon plasma from lattice QCD,” Phys. Lett. B 800,
135119 (2020).
R. Larsen, S. Meinel, S. Mukherjee, and P. Petreczky, “Thermal broadening of bottomonia: Lattice nonrelativistic QCD with extended
operators,” Phys. Rev. D 100, 074506 (2019).
J. R. Green, M. Engelhardt, N. Hasan, S. Krieg, S. Meinel, J. W. Negele, A. V. Pochinsky, and S. N. Syritsyn, “Excited-state eﬀects innucleon structure on the lattice using hybrid interpolators,” Phys. Rev. D 100, 074510 (2019).
L. Leskovec, S. Meinel, M. Pflaumer, and M. Wagner, “Lattice QCD investigation of a doubly-bottom b̄b̄ud tetraquark with quantum
numbers I(J P ) = 0(1+ )” Phys. Rev. D 100, 014503 (2019).
N. Hasan, J. Green, S. Meinel, M. Engelhardt, S. Krieg, J. Negele, A. Pochinsky, and S. Syritsyn, “Nucleon axial, scalar, and tensor
charges using lattice QCD at the physical pion mass,” Phys. Rev. D 99, 114505 (2019).
T. Izubuchi, S. Syritsyn et al., “Valence parton distribution function of pion from fine lattice,” Phys. Rev. D 100, 034516 (2019).
E. Rinaldi, S. Srytsyn, et al. “Lattice QCD determination of neutron-antineutron matrix elements with physical quark masses,” Phys. Rev.
D 99, 074510 (2019).
K. -Y. Kim, M. Nishida, M. Nozaki, M. Seo, Y. Sugimoto, and A. Tomiya, “Entanglement after quantum quenches in lifshitz scalar
theories,” J. Stat. Mech. 1909, 093104 (2019) arXiv:1904.01276 [hep-lat]
B. Chakraborty, M. Honda, T. Izubuchi, Y. Kikuchi, and A. Tomiya, “Digital quantum simulation of the schwinger model with topologicalterm via adiabatic state preparation,” arXiv:2001.00485 [hep-lat][Review articles]
T. Aoyama, L. Jin, T. Blum, T. Izubuchi, C. Lehner et al., “The anomalous magnetic moment of the muon in the standard model,”arXiv:2006.04822 [hep-ph]V. Cirgliano, Z. Davoudi, T. Izubuchi et al., “The role of lattice QCD in searches for violations of fundamental symmetries and signals
for new physics,” Eur. Phys. J. A 55, 197 (2019).
P. Gambino, S. Meinel, et al., “Challenges in semileptonic B decays,” arXiv:2006.07287 [hep-ph]W. Detmold, S. Meinel, S. Syritsyn, et al. [USQCD Collaboration]. “Hadrons and nuclei,” Eur. Phys. J. A 55, 193 (2019).
C. Lehner, S. Meinel et al. [USQCD Collaboration]. “Opportunities for lattice QCD in quark and lepton flavor physics,” Eur. Phys. J. A
55, 195 (2019).
T. Izubuchi[Books]K. Hashimoto, A. Tomiya et al., “Physisits use machine learning (in Japanese),” Asakura, October 2019.
K. Hashimoto, A. Tanaka, and A. Tomiya, “Deep Learning and physics (in Japanese),” Kodansha, June 2019.

[Proceedings]
K. Maltman, T. Izubuchi, et al., “Current status of inclusive hadronic τ determinations of |Vus |,” SciPost Phys. Proc. 1, 006 (2019).
M. Kawaguchi, S. Matsuzaki, and A. Tomiya, “Analysis on nonperturbative flavor violation at chiral crossover criticality in QCD,”
arXiv:2005.07003 [hep-ph]
M. Kawaguchi, S. Matsuzaki, and A. Tomiya, “Nonperturbative flavor breaking in topological susceptibility at Hot QCD criticality,”
arXiv:2003.11375 [hep-ph]
H. -T. Ding, S. -T. Li, S. Mukherjee, A. Tomiya, and X. -D. Wang, “Meson masses in external magnetic fields with HISQ fermions,”
arXiv:2001.05322 [hep-lat]
H. -T. Ding, O. Kaczmarek, F. Karsch, S. -T. Li, S. Mukherjee, A. Tomiya, and Y. Zhang, “Dirac Eigenvalue spectrum of Nf = 2+1 QCD- 385 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

towards the chiral limit using HISQ fermions,” arXiv:2001.05217 [hep-lat]
A. Tomiya, H. -T. Ding, X. -D. Wang, Y. Zhang, S. Mukherjee, and C. Schmidt, “Phase structure of three flavor QCD in external magnetic
fields using HISQ fermions,” arXiv:1904.01276 [hep-lat]

Presentations[International conference/workshops]
L. Jink (invited), “QED corrections to hadron masses,” χ QCD collaboration meeting at University of Kentucky, December 13, 2019.
L. Jin (invited), “Status of Muon g − 2,” Brookhaven Forum 2019: Particle Physics and Cosmology in the 2020’s, September 26, 2019.
L. Jin (invited), “Hadronic Light-by-Light RBC,” Hadronic contributions to (g − 2) µ , INT Workshop INT-19-74W, September 11, 2019.
L. Jin (invited, plenary) “QED∞ in muon g − 2, hadron spectroscopy, and beyond,” 37th international conference on lattice field theory,
June 20, 2019.
A. Tomiya (invited), “Applications of machine learning to computational physics,” A.I. for nuclear physics (invited), Jeﬀerson Laboratory,
Virginia, USA, November 3, 2020.
A. Tomiya, “Chiral condensate in Schwinger model by quantum computer,” International Workshop on “Theoretical Particle Physics
2019,” Tokyo, Japan, November 4, 2019.
A. Tomiya, “Phase structure of three flavor QCD in external magnetic fields,” XQCD 2019, Tokyo, Japan, June 2019.
A. Tomiya, “Phase structure of three flavor QCD in external magnetic fields,” Lattice 2019, Wuhan, China, June 2019.

[Domestic Conferences/Workshops]
A. Tomiya, “Phase structure of three flavor QCD in external magnetic fields,” JPS meeting, Kyushu University, March 2019.
A. Tomiya, “QCD phase transition under external magnetic field with improved staggered fermions,” JPS meeting, Tokyo University of
Science, March 2018.

[Seminars]
A. Tomiya, “Lattice gauge theory with quantum computers,” (Virtual) RIKEN Center for Computational Science, Japan, June 3, 2020.
A. Tomiya, “Lattice gauge theory with quantum computers,” (Virtual) Osaka university, Japan, May 12, 2020.
A. Tomiya, “An introduction to deep learning (lecture),” Jamstec (Japan Agency for Marine-Earth Science and Technology), Japan,
January 13, 2019.
A. Tomiya, “An introduction to lattice gauge theories (lecture),” Math club, Tokyo, Japan, December 28, 2019.
A. Tomiya, “An introduction to deep learning (lecture),” Kochi Technological university, Kochi, Japan, December 13, 2019.
A. Tomiya, “An introduction to Machine learning and science (lecture),” Kochi Technological university, Kochi, Japan, December 13,
2019.
A. Tomiya, “An introduction to lattice gauge theories (lecture),” Jilin U, China, November 18, 2019.
A. Tomiya, “An introduction to deep learning (lecture),” Waseda U (hpc-phys working group), Japan, November 7, 2019.
A. Tomiya, “Phase transition in three flavor QCD with background magnetic field,” Jilin U, China, September 24, 2019.
A. Tomiya, “Phase transition in three flavor QCD with background magnetic field,” Keio, Japan, July 10 2019.
A. Tomiya, “Applications of machine learning to computational physics,” Brookhaven National Laboratory, NY, US, May 30, 2019.
A. Tomiya, “Towards reduction of autocorrelation in HMC by machine learning,” Riken CCS, Kobe, Japan, March 29, 2019.
A. Tomiya, “Deep Learning and Holographic QCD,” Riken, Wako, Japan, December 10, 2018.

AwardsL. Jin and K. G. Wilson, “For his outstanding contributions to the calculation of the hadronic light-by-light scattering component of theanomalous magnetic moment of the muon,” Award for Excellence in Lattice Field Theory, 2019.
L. Jin, “Lattice Calculation of the QED Correction to Meson Leptonic Decay,” U.S. Department of Energy (DOE), Early Career Research
Program, Proposal 0000253629.
S. Syritsyn, “Nucleon Structure, Fundamental Symmetries, and Lattice QCD,” U.S. National Science Foundation (NSF), Career Award
A. Tanaka and A. Tomiya, “Particle Physics Medal, Young Scientist Award in Theoretical Particle Physics,” Japan Particle and Nuclear
Theory Forum, 2019.
A. Tanaka and A. Tomiya, “Journal of the Physical Society of Japan Most Cited Articles in 2018 from Vol.86 (2017),” Journal of the
Physical Society of Japan, 2019.
T. Izubuchi, BNL Science and Technology Award, 2020.

Press Releases
https://www.bnl.gov/newsroom/news.php?a=117139
May 5, 2020, RIKEN, Brookhaven National Laboratory, Columbia University, Universities of Connecticut, Nagoya, Regensburg,“Four Years of Calculations Lead to New Insights into Muon Anomaly”- 386 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Subnuclear System Research Division
RIKEN Facility Oﬃce at RAL
1. Abstract
Our core activities are based on the RIKEN-RAL Muon Facility located at the ISIS Neutron & Muon Source at the Rutherford
Appleton Laboratory (UK), which provides intense pulsed-muon beams. The RIKEN-RAL Muon Facility is a significant and longstanding collaboration between RIKEN and RAL in muon science—with 2020 being the 30th years of continuous agreements between
RIKEN and RAL. The Facility enables muon science throughout Japan and other field—it continues to attract proposals from a wide
variety of Japanese universities and institutions (with over 80 groups having now used the facility), and including industrial users suchat Toyota, and has been instrumental in establishing scientific links with other Asian universities.
Muons have their own spins with 100% polarization, and can detect local magnetic fields and their fluctuations at muon stoppingsites very precisely. The method to study the characteristics of materials by observing time dependent changes of muon spin polarization is called “Muon Spin Rotation, Relaxation and Resonance” (µSR method), and is applied to study electro-magnetic properties
of insulating, metallic, magnetic and superconducting systems. Muons reveal static and dynamic properties of the electronic state ofmaterials in the zero-field condition, which is the ideal magnetic condition for research into magnetism. For example, we have carriedout µSR investigations on a wide range of materials including frustrated pyrochlore systems, which have variety of exotic groundstates of magnetic spins, so the magnetism study of this system using muon is quite unique.
The ultra-cold muon beam can be stopped in thin foil, multi-layered materials and artificial lattices, which enables us to apply theaSR techniques to surface and interface science. The development of an ultra-cold muon beam is also very important as a source of
pencil-like small emittance muon beam for muon g-2/EDM measurement. We have been developing muonium generators to create
more muonium atoms in vacuum even at room temperature to improve beam quality compared with the conventional hot-tungsten
muonium generator. We have demonstrated a strong increase in the muonium emission eﬃciency by fabricating fine laser drill-holeson the surface of silica aerogel. We are also developing a high power Lyman-alpha laser in collaboration with the Advanced Photonics
group at RIKEN. The new laser will ionize muoniums 100 times more eﬃciently for slow muon beam generation.
Over the past 2–3 years, a significant development activity in muon elemental analysis has taken place, proton radius experiments
have continued and been developed, and chip irradiation experiments have also continued.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Materials science by muon-spin-relaxation method and muon site calculation
Development of elemental analysis using pulsed negative muons
Nuclear and particle physics studies via muonic atoms and ultra-cold muon beam
Other muon applications

3. Summary of Research Activity(1) Material Science at the RIKEN-RAL Muon Facility
Muons have their own spins with 100% polarization, and can detect local magnetic fields and their fluctuations at muon stoppingsites very precisely. The µSR method is applied to studies of newly fabricated materials. Muons enable us to conduct (1) material
studies under external zero-field condition, (2) magnetism studies with samples without nuclear spins, and (3) measurements of muon
spin relaxation changes at wide temperature range with same detection sensitivity. The detection time range of local field fluctuations
by µSR is 10−6 to 10−11 second, which is an intermediate region between neutron scattering method (10−10 −10−12 second) and Nuclear
Magnetic Resonance (NMR) (longer than 10−6 second). At Port-2 and 4 of the RIKEN-RAL Muon Facility, we have been performingµSR researches on strong correlated-electron systems, organic molecules, energy related materials and biological samples to study
electron structures, superconductivity, magnetism, molecular structures and crystal structures.
Among our scientific activities on µSR studies from year 2017 to 2020, following subjects of material sciences are most importantachievements at the RIKEN-RAL muon facility:(1) Deformed nodal superconducting gap state and asymmetric spin-fluctuation mediated Cooper pair in the quasi twodimensional organic superconductor λ-[BETS]2 GaCl4(2) Multi magnetic transitions in the Ru-based pyrochlore systems, R2 Ru2 O7 .
(3) Magnetic properties of the nano-cluster gold in the border of macro- and micro- scale.
(4) Novel magnetic and superconducting properties of nano-size La-based high-TC superconducting cuprates.
(5) Determination of muon positions estimated from density functional theory (DFT) and dipole-field calculations.
(6) Chemical muonic states in DNA molecules.
Result-1) We developed a novel method to determine deformed superconducting-gap structure with the density functional theory
calculations. It was concluded that the two-dimensional organic superconductor λ-[BETS]2 GaCl4 has a deformed nodal gap which
has the steeper width rather than that of the d-wave state. Result-2) Doped hole eﬀects on the magnetic properties of corner-sharedmagnetic moments on pyrochlore systems gave us new interpretations to understand exotic phenomena, like the quantum criticalityof magnetic moments and a quasi-magnetic monopole state. Result-3) and 4) The nano-size eﬀect show a new scheme of electronic
properties of metallic element. We confirmed that the nano-gold cluster can have free electronic moment on one nano-cluster. The
same nano-size eﬀect was examined on the La-based high-TC superconducting oxide changing the electronic state from insulating tosuperconducting. We confirmed the reduction in the magnetic interaction and the disappearance of the superconducting state leading- 387 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

the increase in the ferromagnetic interaction within the wide-range of the hole concentration. Result-5) Well known and deeply
investigated La2 CuO4 has opened a new scheme of the Cu spin. Taking into account quantum eﬀects to expand the Cu-spin orbital
and muon positions, we have succeeded to explain newly found muon sites and hyperfine fields at those sites.
We have been continuing to develop muon-science activities in Asian countries. We enhanced international collaborations toorganize new µSR experimental groups and to develop muon-site calculation groups using computational method. We are creating
new collaborations with new teams in diﬀerent countries and also continuing collaborations in µSR experiments on strongly correlated
systems with researchers from Taiwan, Indonesia, China, Thailand and Malaysia including graduate students. We are starting tocollaborate with the new Chinese muon group who are developing the Chinese Muon Facility and trying to develop more muon
activities in the Asian area.
(2) Development of elemental analysis using pulsed negative muons
There has been significant development of elemental analysis using negative muons on Port 4 and Port 1 over the past coupleof years. Currently, elemental analysis commonly uses X-ray and electron beams, which accurately measure surfaces. However asignificant advantage of muonic X-rays over those of electronic X-rays is their higher energy due to the mass of the muon. These highenergy muonic X-rays are emitted from the bulk of the samples without significant photon self-absorption. The penetration depth ofthe muons can be varied by controlling the muon momentum, providing data from a thin slice of sample at a given depth. This can beover a centimetre in iron, silver and gold or over 4 cm in less dense materials such as carbon.
Some techniques for elemental analysis are destructive or require the material under investigation to undergo significant treatment
and some of the techniques are only sensitive to the surface. Therefore, negative muons oﬀer a unique service in which they canmeasure inside, beyond the surface layer and completely non-destructively.
The areas of science that have used negative muons for elemental analysis have been very diverse. The largest area is the cultural
heritage community as the non-destructive ability is particularly important and will become more so. This community have investigated swords from diﬀerent eras, coins (Roman gold and silver, Islamic silver and from the Tudor Warship Mary Rose), miniatureboats from Sardinia, reliefs on Baptist church gate, Bronze Age tools and cannon balls. In addition, energy materials (Li composition
for hydrogen storage), bio-materials (search for iron to potentially help understand Alzheimer’s), engineering alloys (manufacturing
processes for new materials for jet engines), and functional materials (surface eﬀects in piezo electrics) have also been investigated.
The study was extended to see the diﬀerence by isotopes of silver and lead, which may give hint on the source of the material.
(3) Ultra-cold (low energy) Muon Beam Generation and Applications
Positive muon beam with thermal energy has been produced by laser ionization of muonium (bound system of µ+ and electron)
emitted from a hot tungsten surface with stopping surface muon beam at Port-3. The method generates a positive muon beam withacceleration energy from several 100 eV to several 10 keV, small beam size (a few mm) and good time resolution (less than 8 nsec).
By stopping the ultra-cold muon beam in thin foil, multi-layered materials and artificial lattices, we can precisely measure local
magnetic field in the materials, and apply the µSR techniques to surface and interface science. In addition, the ultra-cold muon is very
important as the source of pencil-like small emittance muon beam for muon g-2/EDM measurement. It is essential to increase the slow
muon beam production eﬃciency by 100 times for these applications. There are three key techniques in ultra-cold muon generation:
production of thermal muonium, high intensity Lyman-alpha laser and the ultra-cold muon beam line.
A high-power Lyman-alpha laser was developed in collaboration with the Advanced Photonics group at RIKEN. The new laser
system is used at J-PARC U-line and, upon completion, will ionize muoniums 100 times more eﬃciently for slow muon beam
generation. In this development, we succeeded to synthesize novel ceramic-based Nd:YGAG crystal, which realized a highly eﬃcientand stable laser system. However, larger size crystal than presently available is needed for full design power. We are working hard to
improve the crystal homogeneity including the option of using slightly diﬀerent material.
We also succeeded in developing an eﬃcient muonium generator, laser ablated silica aerogel, which emits more muoniums into
vacuum even at room temperature. Study has been done at TRIUMF utilizing positron tracking method of muon decay position.
We demonstrated in 2013 at least 10 times increase of the muonium emission eﬃciency by fabricating fine laser drill-holes on thesurface of silica aerogel. Further study was carried out in 2017 to find the optimum fabrication that will maximize the muonium
emission. From the analysis, we found the emission has large positive correlation with the laser ablated area rather than with anyother parameters. We also confirmed the muon polarization in vacuum. An alternative detection method for muonium emission using
muonium spin rotation, which will be sensitive even to muoniums near the surface, was tested at RIKEN-RAL in 2018 and was foundsuccessful. The study was further applied the measurement of the temperature dependence.
In RIKEN-RAL Port 3, the ultra-cold muon beam line, which had been designed with hot tungsten, was completely rebuilt touse advantage of the new room temperature silica aerogel target. The equipment was tested with surface muon beam and basic datasuch as muon stopping in aerogel were taken. We are waiting the laser crystal development in order to proceed to ultra-cold muon
generation. A similar target design will be adopted in the ultimate cold muon source planned for muon g-2/EDM at J-PARC.
(4) Other Fundamental Physics Studies
A measurement of the proton radius using 2S-2P transition of muonic hydrogen at PSI revealed that the proton charge radius
is surprisingly smaller than the radius measured using normal hydrogen spectroscopy and e-p scattering by more than 5 times theirexperimental precision. The muonic atom has larger sensitivity to the proton radius because the negative muon orbits closer tothe proton, although there is no reason why these measurements can yield inconsistent results if there exists no exotic physics orunidentified phenomenon behind. The cause of the discrepancy is not understood yet, thus a new measurement with independent
method is much anticipated.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

We proposed the measurement of the proton radius by using the hyperfine splitting of the muonic hydrogen ground state. This
hyperfine splitting is sensitive to the Zemach radius, which is a convolution of charge and magnetic-dipole distributions inside proton.
We are planning to re-polarize the muonic hydrogen by a circularly polarized excitation laser (excites one of the F = 1 states andregenerates the muon spin polarization), and detect the recovery of the muon decay-asymmetry along the laser.
At RIKEN, we are developing dedicated laser system (mid-infrared high-power pulse laser system at around 6 µm). We havetested the eﬃciency of our wavelength conversion scheme. We are going to test band-width narrowing using a seed laser of (Quantum
Cascade Laser) and the laser reflection cavity. Preparation using muon beam is also in progress. We measured the muon stopping
distribution in low-density hydrogen-gas cell, which gave us consistent results with beam simulation. Another key is the lifetime of
the upper hyperfine state of the muonic hydrogen that will contribute the polarization. We successfully observed the clear muon spin
precession of muonic deuterium atom in 2018 for the first time in the world. The measurement with muonic protium was carried out
in 2019.
(5) Other topics
RIKEN and ISIS have signed a new collaboration agreement for the period 2018–2023. This is the fourth in a continuous series ofagreements, the first being signed in 1990, resulting in a partnership which will have lasted over 30 years. Under the new agreement,
ownership and operation of the facility was passed to ISIS, a refurbishment programme of the facility has started, a user programme forJapanese scientists continued under the partnership between RIKEN and ISIS. The RIKEN-RAL collaboration is regularly highlighted
as a good example of UK-Japanese science partnership at the UK-Japan Joint Committee on Science and Technology (chaired by the
UK Chief Scientific Advisor to Government and a counterpart from Japan)—for example, Dr. King and Dr. Watanabe presented
RIKEN-RAL at the November 2016 meeting of the Committee. The RIKEN-RAL collaboration has also enabled the developmentof collaborative activity between RIKEN and other Asian universities, e.g. through several MoUs with Indonesian and Malaysian
universities.

Members
Director
Philip KING
Research Scientist
Isao WATANABE (Senior Research Scientist)
Contract Researcher
Katsuhiko ISHIDA

List of Publications & Presentations
Publications[Original papers]
M. Abe et al. (J-PARC E34 collaboration), “A new approach for measuring the muon’s anomalous magnetic moment and electric dipole
moment,” Prog. Theor. Exp. Phys. 2019, 053C02 (2019).
M. Clemenza et al., “Muonic atom X-ray spectroscopy for non-destructive analysis of archaological samples,” Journal of Radioanalyticaland Nuclear Chemistry 322, 1357–1363 (2019).
B. V. Hampshire, K. Butcher, K. Ishida, G. Green, D. Paul, and A. Hillier, “Using negative muons as a probe for depth profiling silver
Roman coinage,” Heritage 2, 400–407 2019.
S. Asano, K. M. Suzuki, K. Kudo, I. Watanabe, A. Koda, R. Kadono, T. Noji, Y. Koike, T. Taniguchi, S. Kitagawa, K. Ishida, andM. Fujita, J. Phys. Soc. Jpn. 88, 084709-1–6 (2019).
F. Astuti, M. Miyajima, T. Fukuda, M. Kodani, T. Nakano, T. Kambe, and I. Watanab, J. Phys. Soc. Jpn. 88, 043701-1–5 (2019).
M. A. Baqiya, T. Adachi, A. Takahashi, T. Konno, T. Ohgi, I. Watanabe, and Y. Koike, “Muon-spin relaxation study of the spin correlationsin the overdoped regime of electron-doped high-TC cuprate superconductors,” Phys. Rev. B 100, 064514-1–5 (2019).
S. Wenner, C. Marioara, K. Nishimura, K. Matsuda, S. Lee, T. Namiki, I. Watanabe, T. Matsuzaki, and R. Holmestad, “Muon spin
relaxation study of solute-vacancy interactions during natural aging of Al-Mg-Si-Cu alloys,” Metallurgical and Materials Transactions
A 50, 3446–3451 (2019).

Presentations[International conferences/workshops]
K. Ishida (oral), “Status of the g-2 and EDM experiment at J-PARC,” FCCP2019, Anacapri, Italy, August 29–31, 2019.
K. Ishida (oral), “Measurement of the proton Zemach radius from the hyperfine splitting in muonic hydrogen utilizing muon spin repolarization with laser: Principle and Method,” Proton Radius 2019, Veli Losinji, Croatia, September 15–20, 2019.
S. Kanda (oral), “Measurement of the proton Zemach radius from the hyperfine splitting in muonic hydrogen utilizing muon spin repolarization with laser: Preparation Status,” Proton Radius 2019, Veli Losinji, Croatia, September 15–20, 2019.
K. Ishida (oral), “Status of the g-2 and EDM experiment at J-PARC,” Proton Radius 2019, Veli Losinji, Croatia, September 15–20, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

K. Ishida (oral), “Laser spectroscopy of the 1 s hyperfine splitting energy of muonic hydrogen for the determination of proton Zemachradius,” The 3rd J-PARC symposium (J-PARC2019), Tsukuba, Japan, September 23–26, 2019.
I. Watanabe (oral), The 1st International MIPAnet Conference on Science and Mathematics (IMC-SciMath 2019), Parapat, Indonesia,
October 9–11, 2019.
I. Watanabe (oral), 4th Padjadjaran International Physics Symposium (PIPS2019), Bandung, Indonesia, November 13–14, 2019.
I. Watanabe (oral), International Conference on Magnetism and Its Application (IICMIA2019), Solo, Indonesia, November 20–21, 2019.

[Domestic conferences/workshops]ੴాউ඙ʢট଴ߨԋʣ, ʮӳࠃཧ‫ ݚ‬RAL ϛϡΦϯࢪઃͱϛϡΦϯར༻෼ੳʯ, ୈ 2 ճจཧ༥߹γϯϙδ΢Ϝ ྔࢠϏʔϜͰྺ࢙Λ୳Δ—Ճ଎‫͕ث‬๰͙จཧ༥߹ͷ஍ฏ—, େࡕେֶத೭ౡηϯλʔ, େࡕ, 2019 ೥ 12 ݄ 25 ೔–26 ೔.
ੴాউ඙ʢ‫ޱ‬಄ൃදʣ, ʮཧ‫ ݚ‬RAL ͷ‫ݱ‬ঢ়ͱల๬ʯ, ୈ 10 ճʮmuon ՊֶͱՃ଎‫ڀݚث‬ʯ‫ڀݚ‬ձ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2020 ೥ 1 ݄
8 ೔–9 ೔.

[Seminars]
RIKEN Symposium, “International workshop of topological quantum materials,” Tainan, Taiwan, January 10–2, 2019.
RIKEN Symposium, “The 5th international symposium in current progress in mathematics and sciences,” Depok, Indonesia, July 9–10,
2019.

AwardsS. Winarsih, RIKEN Summer School 2019, Poster Prizeʢin Physicsʣ
S. Winarsih, RIKEN Summer School 2019, Poster PrizeʢBest Presentationʣ
S. Winarsih, RIKEN Exchange Meeting 2019, Poster PrizeʢStudent Sectionʣ

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Safety Management Group
1. Abstract

The RIKEN Nishina Center for Accelerator-Based Science possesses one of the largest accelerator facilities in the world, which
consists of two heavy-ion linear accelerators and five cyclotrons. This is the only site in Japan where uranium ions are accelerated.
The center also has electron accelerators of microtron and synchrotron storage ring. Our function is to keep the radiation level inand around the facility below the allowable limit and to keep the exposure of workers as low as reasonably achievable. We are also
involved in the safety management of the Radioisotope Center, where many types of experiments are performed with sealed andunsealed radioisotopes.

2. Major Research Subjects(1) Safety management at radiation facilities of Nishina Center for Accelerator-Based Science(2) Safety management at Radioisotope Center(3) Radiation shielding design and development of accelerator safety systems

3. Summary of Research Activity

Our most important task is to keep the personnel exposure as low as reasonably achievable, and to prevent an accident. Therefore,
we daily patrol the facility, measure the ambient dose rates, maintain the survey meters, shield doors and facilities of exhaust air
and wastewater, replenish the protective supplies, and manage the radioactive waste. Advice, supervision and assistance at major
accelerator maintenance works are also our task.
The interlock system for which is the part of the radiation control system developed for the RILAC upgrade was installed andstarted to operate. Access management system for the RILAC building, which was installed previous year, was improved to control
Minor improvements of the radiation safety systems were also done. The old UPS for radiation management system of Nishinabuilding was replaced. Halogen sensitive filter for the exhaust system of Nishina building was newly installed.

Members
Director
Kanenobu TANAKA
Research/Technical Scientists
Rieko HIGURASHI (Technical Scientist)

Hisao SAKAMOTO (Technical Scientist)

Expert Technician
Atsuko AKASHIO
Technical Staﬀ I
Hiroki MUKAI
Junior Research Associate
Kenta SUGIHARA
Visiting Scientists
Masayuki HAGIWARA (KEK)
Noriaki NAKAO (Shimizu Corporation)
Toshiya SANAMI (KEK)

Nobuhiro SHIGYO (Kyushu Univ.)
Hiroshi YASHIMA (Kyoto Univ.)

Student Trainees
Shougo IZUMITANI (Kyushu Univ.)

Eunji LEE (Kyushu Univ.)

Part-time Workers
Kimie IGARASHI (Administrative Part-time Worker I)
Satomi IIZUKA (Administrative Part-time Worker II)

Yukiko SHIODA (Administrative Part-time Worker II)
Naoko USUDATE (Administrative Part-time Worker II)

Temporary Staﬃng
Ryuji SUZUKI
Assistant
Tomomi OKAYASU- 391 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Proceedings]
ాத৊৴,ʮେ‫ن‬໛Ճ଎‫ࢪث‬ઃʹ͓͚Δ, ࣄ‫࣌ނ‬ͷԁ‫ͳ׈‬δϣ౬ํ఻ୡͱආ೉ͷऔΓ૊Έʯ, ೔ຊ์ࣹઢ҆શ؅ཧֶձࢽ 18, 2 (2019).
޲Ҫ߂थ, ాத৊৴, ্ຸٛ๎,ʮRIBF Ճ଎‫ࢪث‬ઃͷྫྷ٫ਫʹؔ͢Δ์ࣹઢ؅ཧʯ, Isotope News 762, 4 (2019).

Presentations[International conferences/workshops]
K. Tanaka (oral), “Recent trouble and measures in unsealed radioisotope handling at RIBF,” International Technical Safety Forum 2019,
Lund, Sweden, May 13–17, 2019.
K. Tanaka (invited), “Radiation evaluation in RIBF,” Tsukuba, Japan, September 23–26, 2019.
K. Sugihara(poster), “Measurement of neutron energy spectra of 345 MeV/u 238 U Incidence on a Cu Target,” 2019 Symposium on Nuclear
Data, Kasuga, Japan, November 28–30, 2019.
S. Izumitani(poster), “Production via the 7 Li(p ,n) 7 Be reaction with 2.49 MeV proton injection,” 2019 Symposium on Nuclear Data,
Kasuga, Japan, November 28–30, 2019.

[Domestic conference/workshops]ాத৊৴ (ট଴ߨԋ),ʮRIBF ͷΠϯλʔϩοΫͱӡ༻ʯ, ୈ 7 ճՃ଎‫ࢪث‬ઃ҆શγϯϙδ΢Ϝ, ౦ւଜ, 2020 ೥ 1 ݄ 23–24 ೔.

Awards[Excellent poster award]
S. Izumitani, “Production via the 7 Li(p, n) 7 Be reaction with 2.49 MeV proton injection,” 2019 Symposium on Nuclear Data, Kasuga,
Japan, November 28–30, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

User Liaison Group
1. Abstract
The essential mission of the User Liaison Group is to maximize the research activities of RIBF by attracting users in various fields
with a wide scope. The Group consists of two teams. The RIBF User Liaison Team provides various supports to visiting RIBF users
through the RIBF Users Oﬃce. Managing RIBF beam time and organizing the Program Advisory Committee Meetings to review
RIBF experimental proposals are also important mission of the Team in order to enhance collaborative-use of the RIBF. The OutreachTeam has created various information materials, such as pamphlets, posters, and homepages, to introduce the research activities in
the RNC. On the homepage, we provide information on usage of the RIBF facility. The team also participate in science introduction
events hosted by public institutions. In addition, the User Liaison Group also takes care of laboratory tours for RIBF visitors frompublic. The numbers of visitors amounts to 2,300 per year.

Members
Director
Hideki UENO
Research Consultants
Ikuko HAMAMOTO (The Lund Univ.)

Munetake ICHIMURA (Univ. of Tokyo)

Assistants
Yu NAYA
Tomomi OKAYASU

Midori YAMAMOTO- 393 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

User Liaison GroupRIBF User Liaison Team
1. Abstract
To enhance synergetic common use of the world-class accelerator facility, the Radioisotope Beam Factory (RIBF), it is necessary
to promote a broad range of applications and to maximize the facility’s importance. The facilitation and promotion of the RIBF are
important missions charged to the team. Important operational activities of the team include: i) the organization of international Program Advisory Committee (PAC) meetings to review experimental proposals submitted by RIBF users, ii) RIBF beam-time operation
management, and iii) promotion of facility use by hosting outside users through the RIBF Independent Users program, which is a
new-user registration program begun in FY2010 at the RIKEN Nishina Center (RNC) to enhance the synergetic common use of the
RIBF. The team opened the RIBF Users Oﬃce in the RIBF building in 2010, which is the main point of contact for Independent Usersand provides a wide range of services and information.

2. Major Research Subjects(1) Facilitation of the use of the RIBF
(2) Promotion of the RIBF to interested researchers

3. Summary of Research Activity(1) Facilitation of the use of the RIBF
The RIBF Users Oﬃce, formed by the team in 2010, is a point of contact for user registration through the RIBF Independent User
program. This activity includes:• registration of users as RIBF Independent Users,• registration of radiation workers at the RIKEN Wako Institute,• provision of an RIBF User Card (a regular entry permit) and an optically stimulated luminescence dosimeter for each RIBF
Independent User, and• provision of safety training for new registrants regarding working around radiation, accelerator use at the RIBF facility, andinformation security, which must be completed before they begin RIBF research.
The RIBF Users Oﬃce is also a point of contact for users regarding RIBF beam-time-related paperwork, which includes:• contact for beam-time scheduling and safety review of experiments by the In-House Safety Committee,• preparation of annual Accelerator Progress Reports, and• maintaining the above information in a beam-time record database.
In addition, the RIBF Users Oﬃce assists RIBF Independent Users with matters related to their visit, such as invitation procedures,visa applications, and the reservation of on-campus accommodation.
(2) Promotion of the RIBF to interested researchers• The team has organized an international PAC for RIBF experiments; it consists of leading scientists worldwide and reviews
proposals in the field of nuclear physics (NP) purely on the basis of their scientific merit and feasibility. The team also assists
another PAC meeting for material and life sciences (ML) organized by the RNC Advanced Meson Laboratory. The NP and ML
PAC meetings are organized twice a year.
• The team coordinates beam times for PAC-approved experiments and other development activities. It manages the operatingschedule of the RIBF accelerator complex according to the decisions arrived at by the RIBF Machine Time Committee.
• To promote research activities at RIBF, proposals for User Liaison and Industrial Cooperation Group symposia/mini-workshops
are solicited broadly both inside and outside of the RNC. The RIBF Users Oﬃce assists in the related paperwork.
• The team is the point of contact for the RIBF users’ association. It arranges meetings at RNC headquarters for the RIBF User
Executive Committee of the users’ association.
• The Team conducts publicity activities, such as arranging for RIBF tours, development and improvement of the RNC oﬃcial web
site, and delivery of RNC news via email and the web.

Members
Team Leader
Ken-ichiro YONEDA
Contract Researcher
Tadashi KAMBARA- 394 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

User Liaison Group
Outreach Team
1. Abstract
The Outreach Team has created various information materials to introduce research activities in the RNC. For instance, the teammakes brochures introducing the RNC and the RIBF accelerator facility, posters of symposia and the summer school hosted by RNC,
the center homepage containing information such as details of RNC and the procedure for the use of the RIBF facility, and images ofequipment and facilities available for researchers inside and outside RIKEN, among the others. Furthermore, the team also participatesin science introduction events hosted by public institutions.

2. Major Work Contents
The major work contents of the Outreach Team is to promote the publicity of RNC, through the creation of various materials suchas brochures, websites, posters, and videos, among the others. The arrangement of tours of the RIBF facility and the exhibition andintroduction of the RIBF facility at science events are also conducted independently or in cooperation with RIKEN Public Relations
Oﬃce.

3. Summary of Work Activity
The specific work contents performed by the team are as follows:• [Website] The Team creates/manages the RNC oﬃcial website (http://www.nishina.riken.jp), which introduces the organization and its research activities. This website plays an important role in providing information to researchers who visit RNC
to conduct his/her own research.
• [Brochures] The Team has produced various brochures introducing the organization and the studies performed at RNC. The
brochures named “Your body is made of star scraps” explaining element synthesis in the universe and “Introduction of RIBF
Facility” in a cartoon style for children are among them.
• [Posters] Conference/Symposium posters connected with RNC were prepared on the request of organizers. For general purpose,a special poster featuring the nuclear chart has been prepared for distribution. In commemoration of the discovery of nihonium,
brochures and posters dedicated to the ceremony were made.
• [RIBF Cyclopedia] In April 2012, the permanent exhibition hall (RIBF Cyclopedia) located at the entrance hall of the RIBF
building was set up in cooperation with RIKEN Public Relations Oﬃce. Explanatory illustrations on nuclear science, research at
RIBF, RIBF history, a 3D nuclear chart built with LEGO blocks, and a 1/6-size GARIS model are displayed to help understanding
through visual means. The Team is also working on updating the exhibits.
• [RIBF facility tour] The Team arranges RIBF facility tour for over 2000 visitors per year. The tour is guided by a researcher.
• [Science event participation] In 2010, 2012, 2013, 2015, and 2016, the sub-team opened an exhibition booth of RNC to introduce
the latest research activities on the occasion of the “Science Agora” organized by Japan Science and Technology Agency (JST).
From time to time, the sub-team was invited to participate in scientific events by MEXT, Wako city, and Nissan global foundation.
One attraction targeting children is the hands-on work of assembling “Iron-beads” to create a nuclear chart or a shape of nihonium.
In addition to the above-noted work contents, the Team conducts a variety of works, such as taking pictures of meetings organized by
RNC, cooperation in the production of a 3D video to explain the accelerators and the research at RIBF, among the others.

Members
Team Leader
Hideki UENO
Deputy Team Leader
Yasushi WATANABE
Technical Staﬀ I
Narumasa MIYAUCHI

List of Publications & Presentations
Outreach activities
Special Exhibition of the International Year of the Periodic Table 2019ʢࠃࡍप‫ظ‬ද೥ಛผల 2019ʮཧԽֶ‫ॴڀݚ‬ͷχϗχ΢Ϝ໛‫ܕ‬Λͭ͘Ζ͏ʯʣ, Niihama (Ehime Prefectural Science Museum), January 18–19, 2020.
RIKEN Osaka Campus Open Day 2019, Suita, November 23, 2019.
Science Agora 2019 (an open forum organized by the Japan Science and Technology Agency), Tokyo (The National Museum of Emerging
Science and Innovation), November 15–17, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Oﬃce of the Center Director
Summary of Research Activity
This oﬃce is in place from JFY2018 to support the center director in subjects which the promotion oﬃce is not able to cover. It
also works as a home laboratory for research administrators and assistants with an indefinite term contract. This year’s most important
activity of the oﬃce was to support the International Symposium on Superheavy Elements (SHE2019) held at Hakone, Japan from 1st
to 5th of December 2019. The Chair parsons K. Morita and H. Haba run the symposium and were supported largely by this oﬃce;
research administrator Narumasa MIYAUCHI and assistants Noriko ASAKAWA and Noriko KIYAMA. Miyachi also contributed
largely to the International Year of Periodic table (IYPT2019), in the preparation of the travelling exhibitions and the preparationof the session “Creation of superheavy elements” in the IYPT2019 Closing Ceremony. His handmade video of “The Landscape of
Nihonium Avenue” was greatly appreciated by the audience. Below is a list of activity of Nishina Center Director’s Oﬃce, in public
or semi-public events.
2019.03.01

NuPECC at Warsaw

2019.03.11
2019.03.17

RBRC SRC
JPS meeting at Ito Campus,
Kyushu University

2019.04.17

Nishina Center,
New-commers’ Orientation
Completion Ceremony for
Nihonium Avenue

2019.05.19

2019.05.29

ORNL visit

2019.06.11

Sakura Science High School
Visit

2019.06.24

NCAC

2019.06.28

ML-PAC

2019.07.10

IN-PAC

2019.07.27

Mendeleev 150

2019.08.01

SCK-CEN visit

2019.08.02

IUPAP-WG9

2019.08.21

NICT Visit

2019.08.26

TAN19

2019.09.07

IYPT2019 Special Exhibition
in Kyoto

2019.10.03

J. Soffer’s Memorial2019.10.23
2019.11.00

RAC
Chemistry and Chemical
Industry

Nishina Center is the associate member of (NuPECC: Nuclear Physics European Collaboration
Committee, an Expert Committee of the European Science Foundation). The status report ofNishina Center was presented at their regular meeting at Warsaw, Poland. The minutes areavailable in http://www.nupecc.org/misc/min94.pdf
Nishina Director participated in Scientific Review Committee of RIKEN-BNL Research Center.
As recommended by Nishina Center, Japan Physics Society organized a special joint session for
IYPT2019 at the Ito Campus of Kyushu University with the Chemical Society of Japan at
Kobe-Okamoto Campus of Konan University. K. Morita gave a plenary talk.
In the orientation for new commers in Nishina Center, introductory talk of “Researcher’s MustHave” was given by Nishina Director.
Wako City held the Completion Ceremony of Nihonium Avenue in the RIKEN Wako Campus.
The Mayer Matsumoto invited the donors and students to the Ceremony. The Nishina Director
gave the presentation of “Welcome to the birthplace of 113th element, nihonium (in Japanese)”.
Many of audience also attended the challenge exam for chemical elements, held together with the
ceremony.
Nishina Director visited Oak Ridge National Laboratory to participate in the collaboration
meeting for superheavy element search.
Sakura Science High School, a government-driven virtual school for foreign exchange Students,
visited RIKEN. Nishina Director gave a presentation of “Welcome to the birthplace of 113th
element, nihonium”.
Nishina Center Advisory Committee was held. Nishina Director and the Center activities werereviewed for three days.
Nishina Director gave an introductory talk for ML-PAC (Program Advisory Committee forMaterials and Life Science).
Nishina Director gave an introductory talk for In-PAC( Program Advisory Committee forIndustrial usage), which was held in a closed session.
4th International Conference on the Periodic Table (Mendeleev 150) was held at ITMO University
in Saint Petersburg, Russian Federation (see https://mendeleev150.ifmo.ru/). Nishina Director
gave a lecture titled “History of Nihonium” on behalf of Kosuke Morita. The talk was publishedin https://doi.org/10.1515/pac-2019-0810
Nishina Director visited CNK-CEN which is the Belgian nuclear research centre, to seek forpossible collaboration in MYRRHA(Multi-purpose hYbrid Research Reactor for High-tech
Application).
Nishina Director participated in the annual general meeting for IUPAP-WG9 (Working Group 9)
held at University of Notre Dame in London, UK. Agenda is available athttps://iupap.triumf.ca/icnp/meetings.html.
A delegation from NICT (National Institute of Information and Communication Technology)
visited Nishina Center. Nishina Director made an introduction to them with a story of the first
cyclotron made by Nishina was made on the Paulsen’s arc converted which was developed forradio communication.
Tan19(6th International Conference on the Chemistry and Physics of the Transactinide Elements)
was held in Wilhelmshaven, Germany. Nishina Director was invited to give a lecture “Element
Genesis over 13.8 Billion Universal Years” in a session dedicated to the International Year of
Periodic Table: https://www-win.gsi.de/tan19/symposium.html.
Nishina Director gave a public lecture in the Special Exhibition in Kyoto for the InternationalYear of Periodic Table, titled “13.8 billion years of element genesis, from Big-Bang to nihonium( in Japanese)”.
Nishina Director participated in a memorial symposium for J. Soffer, who was a leading theoristof perturbative QCD and the father of the RHIC spin project, at BNL, NY, USA.
Nishina director gave a presentation in RIKEN Advisory Council.
Nishina Director contributed a report of Mendeleev150 Symposium to the special contents for
IYPT2019 in Chemistry and Chemical Industry, 940, Vol72-11, 2019.

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Ⅵ. RNC ACTIVITIES2019.11.25

Event Myrrha

2019.12.05

IYPT2019 Closing Ceremony

2019.12.01

SHE20192019.12.16

NP-PAC

2020.01.24

ML-PAC

2020.01.00

Nuclear Physics News

2020.01.27

Strategic review of Helmholtz
Association

RIKEN Accel. Prog. Rep. 53

Nishina Director participated in Event MYRRHA (introduction of MYRRHA project to Japanesecommunities) held at Belgian Embassy at Tokyo, Japan
Nishina director was a port of the organizing committee for the closing ceremony of IYPT2019,held in Tokyo, Japan. He produced and chaired a session named “Creation of superheavy
elements” attended by many of actual discoverers. https://iypt.jp
Director’s office fully supported the international Symposium on Superheavy Elements(SHE2019) held at Hakone, Japan from 1st to 5th of December 2019. The Chair parsons are K.
Morita and H. Haba. https://she2019.riken.jp
Nishina Director gave an introductory talk for NP-PAC (Program Advisory Committee for
Nuclear Physics).
Nishina Director gave an introductory talk for ML-PAC (Program Advisory Committee forMaterials and Life Science).
Nishina Director reported “Superheavy Elements at the Closing Ceremony of IYPT” to Nuclear
Physics News, Vol. 30, No. 1, 2020.
Nishina Director visited Helmholtz Association in Berlin, Germany, to review of the scientificfield “MATTER” which includes GSI, DESY and other large-scale laboratories

Members
Director
Hideto EN’YO
Research Administrator
Narumasa MIYAUCHI (concurrently appointed to OutreachTeam)
Assistants
Noriko ASAKAWA
Noriko KIYAMAYu NAYA (concurrently appointed to RIBF User Liaison
Team)
Karen SAKUMA (concurrently appointed to Accelerator
Group)

Asako TAKAHASHI (concurrently appointed to Spin Isospin
Laboratory)
Mitsue YAMAMOTO (concurrently appointed to Meson Science Laboratory)
Izumi YOSHIDA (concurrently appointed to Nuclear Spectroscopy Laboratory)

List of Publications & Presentations
Publications[Proceedings]
Hideto En’yo (invited), “History of nihonium,” Proceedings of Mendeleev 150, Pure and Applied Chemistry, 91, 1941 (2019).

Presentations[International conferences/workshops]
Hideto En’yo (invited), “History of nihonium,” 4th International Conference on the Periodic Table (Mendeleev 150), ITMO University inSaint Petersburg, Russian Federation, July 26–28, (2019).
Hideto En’yo (invited), “Element genesis over 13.8 billion Universal years,” Special Symposium for International Year of Periodic Tablein the 6th International Conference on the Chemistry and Physics of the Transactinide Elements (TAN19), Wilhelmshaven, Germany,
August 25–30, 2019.

Outreach activities
Hideto En’yo, “Welcome to the birthplace of 113th element, nihonium,” a lecture given to the Sakura Science High School, RIKEN-Wako,
June 11, 2019.
Hideto En’yo et al. (invited), “Creation of superheavy elements,” The Closing Ceremony of IYPT2019, Tokyo, Japan, December 5, 2019.
Hideto En’yo, “Superheavy Elements at the Closing Ceremony of IYPT” contributed to Nuclear Physics News 30, 39 2020.
Ԇᢛलਓ, ʮΑ͏ͦ͜, 113 ൪‫ݩ‬ૉχϗχ΢Ϝͷੜ஀஍, ཧ‫ݚ‬ਔՊηϯλʔ΁ʯ, χϗχ΢Ϝ௨Γ‫׬‬੒‫ه‬೦ࣜయʢ࿨ޫࢢओ࠵ʣ, ཧ‫ݚ‬࿨ޫΩϟϯύε, ࿨ޫ, 2019 ೥ 5 ݄ 19 ೔.
Ԇᢛलਓ, ʮ‫ݩ‬ૉ૑੒ͷ 138 ԯ೥: Ϗοάόϯ͔Βχϗχ΢ϜʹࢸΔ·Ͱʯ, ࠃࡍप‫ظ‬ද೥ 2019 ಛผల, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019 ೥ 9
݄ 7 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Partner Institutions

The Nishina Center started research collaboration with universities and research institutes in 2008 under the “Research Partnership”
agreement. This collaboration framework permits an external institute to develop its own projects at the RIKEN Wako campus inequal partnership with the Nishina Center. At present, two institutes, the Center for Nuclear Study (CNS), the University of Tokyo;
and the Wako Nuclear Science Center (WNSC), Institute of Particle and Nuclear Studies (IPNS), High-energy Accelerator Research
Organization (KEK) are conducting research activities under the “Research Partnership” agreement.
The CNS and the Nishina Center signed the partnership agreement in 2008. Until then, the CNS had collaborated in joint programswith RIKEN under the “Research Collaboration Agreement on Heavy Ion Physics” (collaboration agreement) signed in 1998. The
partnership agreement redefines procedures related to the joint programs while keeping the spirit of the collaboration agreement. The
joint programs include experimental nuclear-physics activities using CRIB, SHARAQ, and GRAPE at RIBF, accelerator development,
and activities at RHIC PHENIX.
KEK started low-energy nuclear physics activity at RIBF in 2011 under the Research Partnership System. The joint experimental
programs are based on KISS (KEK Isotope Separator). After the R&D studies on KISS, it became available for users from 2015.
The experimental proposals that request the use of the above-noted devices of the CNS and KEK together with the other RIBF
key devices are screened by the Program Advisory Committee for Nuclear Physics experiments at RI Beam Factory (NP-PAC) The
NP-PAC meetings are co-hosted together with the CNS and KEK.
The activities of the CNS and KEK are reported in the following pages.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Partner Institution
Center for Nuclear Study, Graduate School of Science
The University of Tokyo
1. Abstract

The Center for Nuclear Study (CNS) aims to elucidate the nature of nuclear system by producing the characteristic states where
the Isospin, Spin and Quark degrees of freedom play central roles. These researches in CNS lead to the understanding of the matterbased on common natures of many-body systems in various phases. We also aim at elucidating the explosion phenomena and theevolution of the universe by the direct measurements simulating nuclear reactions in the universe. In order to advance the nuclear
science with heavy-ion reactions, we develop AVF upgrade, CRIB and SHARAQ facilities in the large-scale accelerators laboratories
RIBF. The OEDO facility has been developed as an upgrade of the SHARAQ, where a RF deflector system has been introduced toobtain a good quality of low-energy beam. A new project for fundamental symmetry using heavy RIs has been starting to install new
experimental devices in the RIBF. We promote collaboration programs at RIBF as well as RHIC-PHENIX and ALICE-LHC with
scientists in the world, and host international meetings and conferences. We also provide educational opportunities to young scientists
in the heavy-ion science through the graduate course as a member of the department of physics in the University of Tokyo and throughhosting the international summer school.

2. Major Research Subjects(1) Accelerator Physics(2) Nuclear Astrophysics(3) Nuclear spectroscopy of exotic nuclei(4) Quark physics(5) Nuclear Theory(6) OEDO/SHARAQ project(7) Exotic Nuclear Reaction(8) Low Energy Nuclear Reaction Group(9) Active Target Development(10) Fundamental Physics

3. Summary of Research Activity(1) Accelerator Physics
One of the major tasks of the accelerator group is the AVF upgrade project that included development of ion sources. In 2019, theoperating time of the HyperECR was 2326 hours, which is 76% of the total operating time of the AVF cyclotron. The beam extraction
system of the HyperECR is under development realize a high intensity and low emittance beam. For the pepper-pot emittance monitor
used for the analysis of the beam injection transport system, we optimized the exposure time and gain of digital camera for a varietyof thicknesses of fluorescent agent and was able to keep homogenized measurements despite of thickness. For the beam transport
analysis of the beamline to CRIB, E7B, and EDM experiment from AVF cyclotron, we started developing 4D emittance monitor
because the transverse components of beam are coupled and it is expected to measure high intensity beam in a few seconds.
(2) Nuclear Astrophysics
The main activity of the nuclear astrophysics group is to study astrophysical reactions and special nuclear clustering using the
low-energy RI beam separator CRIB. Several experimental projects on big-bang nucleosynthesis (BBN) are currently under way. To
give a solution to the cosmological 7 Li abundance problem, 7 Be(n, α)/(n, p) astrophysical reactions were studied with the Trojan
Horse method, and the rate of 7 Be(n, p1 ), the (n, p) reaction with 7 Li excitation, is evaluated at the BBN temperature for the first time.
7
Be(d, p) measurement with a 7 Be-implanted target was carried out in 2018, in collaboration with RCNP, Osaka Univ. and JAEA.
8
Li(α, n) reaction has been considered as responsible to the production of nuclei heavier than boron in some models of the BBN. To
solve the discrepancy between the previous measurements of 8 Li(α, n), a new experiment with γ-ray measurement was performed
at CRIB in September 2018. To confirm the exotic linear-chain cluster structure in 14 C nucleus indicated in the previous 10 Be + α
resonant scattering measurement at CRIB, a new measurement was carried out at INFN-LNS, Catania, Italy, under the collaborationof CNS, INFN, Univ. Edinburgh and other institutes, in October 2018. A measurement on 25 Al + p resonant scattering was performed
at CRIB in February 2019, to study the resonances relevant for the astrophysical 22 Mg(α, p) reaction in X-ray bursters.
The main activity of the nuclear astrophysics group is to study astrophysical reactions and special nuclear clustering using the lowenergy RI beam separator CRIB. As the first experiment of the INSPIRATION project, a measurement of the proton-halo 8 B+120 Sn
system at energies around the Coulomb barrier was carried out in April 2019, under the collaboration of Japan and China. This wasto study the reaction mechanism, including the break-up, of the system involving a weakly-bound nucleus, 8B. On the interest of
nuclear clustering in the 14 O nucleus, a measurement of 10 C+α elastic scattering was performed, under the collaboration of Belgium(ULB), Kyoto Univ., Osaka Univ., CNS, and other groups. We identified several peaks in the energy spectrum, which may show theexistence of cluster states. Studies on big-bang nucleosynthesis (BBN) are currently under way. To give a solution to the cosmological7
Li abundance problem, 7 Be(n, α)/(n, p) astrophysical reactions were measured with the Trojan Horse method, and the first reliableevaluation of the rate of 7 Be(n, p1), the (n, p) reaction with 7 Li excitation, at the BBN temperature, was made during 2019. To produce- 400 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

RI beams at CRIB with higher intensity, a project to improve the heat capacity of the cryogenic gas target was initiated in 2019. We
tested several materials for the sealing foils and the flanges, and a thermal monitoring with a thermography was introduced.
(3) Nuclear structure of exotic nuclei
The NUSPEQ (NUclear SPectroscopy for Extreme Quantum system) group studies exotic structures in high-isospin and/or highspin states in nuclei. The CNS GRAPE (Gamma-Ray detector Array with Position and Energy sensitivity) is a major apparatus forhigh-resolution in-beam gamma-ray spectroscopy. Missing mass spectroscopy using the SHARAQ is used for another approach on
exotic nuclei. The group plays a major role in the OEDO/SHARAQ project described below. In 2019, analysis of a new measurementof the 4 He(8 He, 8 Be)4n reaction for better statistics and better accuracy has been proceeding.
(4) Quark Physics
Main goal of the quark physics group is to understand the properties of hot and dense nuclear matter created by colliding heavy
nuclei at relativistic energies. The group has been involved in the PHENIX experiment at Relativistic Heavy Ion Collider (RHIC) at
Brookhaven National Laboratory, and the ALICE experiment at Large Hadron Collider (LHC) at CERN. As for ALICE, the group has
involved in the data analyses, which include the measurement of low-mass lepton pairs in Pb-Pb and p-Pb collisions, J/ψ measurements in p-Pb collisions, long range two particle correlations in p-Pb collisions, and searches for thermal photons in p-Pb collisions.
The group has been involved in the ALICE-TPC upgrade using a Gas Electron Multiplier (GEM). Installation of GEM chambers in
the TPC and commissioning of the TPC were carried out in 2019. The group has started working on the online space-charge distortion
correction of the TPC by utilizing the GPUs and Machine learning technique.
(5) Nuclear Theory
The nuclear theory group participated in a project, “Priority Issue 9 to be tackled by using the Post-K Computer” and promotes
computational nuclear physics utilizing supercomputers. We developed shell-model codes for the conventional Lanczos method andthe Monte Carlo shell model for massively parallel computation. In FY2019, we performed the Monte Carlo shell model calculationsof the Sm isotopes and revealed that the excited states of 154 Sm and 166 Er whose structures were considered to be β/γ vibration can beinterpreted in view of shape coexistence.
(6) OEDO/SHARAQ project
The OEDO/SHARAQ group pursues experimental studies of RI beams by using the high-resolution beamline and the SHARAQ
spectrometer. A mass measurement by TOF-Bρ technique for very neutron-rich successfully reaches calcium isotopes beyond N = 34,
55, 57Ca, and the preparation of publication is ongoing. The experimental study of 0− strength in nuclei using the parity-tansfer charge
exchange (16 O, 16 F) is on progress and the data analysis is on the final stage. The OEDO beamline, which was an upgrade of the highresolution beamline to produce low-energy RI beams, has started the operation in June and has successfully achieved the designed
ion-optical performance. The first and second experiments were performed in October and November, and new data for nuclear
transmutation of long lived fission products (LLFPs) were successfully obtained.
(7) Exotic Nuclear Reaction
The Exotic Nuclear Reaction group studies various exotic reactions induced by beams of unstable nuclei. One subject is inversekinematics (p, n) reaction. In 2017 a set of neutron counters PANDORA was used for the first time at HIMAC facility for the study ofthe 6 He(p, n) reaction. Candidate nuclei to study are high spin isomers such as 52 Fe(12+ ). Development of isomer beam was carriedout.
(8) Low Energy Nuclear Reaction GroupA recoil particle detector for missing mass spectroscopy, named TiNA, had been developed under the collaboration with RIKEN
and RCNP. TiNA consists of 6 sector telescopes. Each of which as a stripped-type SSD and 2 CsI(Tl) crystals. After the test experimentat the tandem facility of Kyushu Univ., TiNA was employed at the physics experiment with OEDO. Development of the tritium target
is still on-going. Several deuterium doped Ti targets were fabricated at the Toyama Univ. They were tested by using d(12 C, d) reaction
at the tandem facility at Kyushu. The amount of deuterium was found to be scattered. The optimum condition to make the target will
be sought for. The production cross section 178m2 Hf was evaluated for the mass production in the future. The digital signal processing
devices for the GRAPE have been developed to measure the cascade transitions from the isomeric state. After chemical separation of
Hf at the hot laboratory at RIBF. The week cascade decay was successfully measured.
(9) Active Target Development
Two types of gaseous active target TPCs called CAT’s and GEM-MSTPC are developed and used for the missing mass spectroscopy. The CAT’s are employed for the study of equation of state of nuclear matter. The measurement of giant monopole resonancein 132 Sn at RIBF with CAT-S and the data analysis is ongoing. In 2017, we developed a larger active target called CAT-M, which has
10-times larger active volume than that of CAT-S. The CAT-M was commissioned at HIMAC and the excitation energy spectrum of136
Xe for proton scattering was measured. The GEM-MSTPC is employed for the nuclear astrophysics study. The data analysis of(α, p) reaction on 18 Ne and 22 Mg and the β-decay of 16 Ne followed by α emission are ongoing.
(10) Fundamental Physics
Although the Standard Model of particle physics is being steadily and successfully verified, the disappearance of the antimatterin the universe could not be suﬃciently explained; a more fundamental framework is required and has to be studied. In order to- 401 -

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understand the mechanism of matter-antimatter symmetry violation, we are developing the next generation experiments employing
ultracold atoms to search for the electron electric dipole moment (EDM) using heavy element francium (Fr) in an optical latticeat RIBF. In 2019, we developed a surface ionizer for production of a high intensity Fr ion beam. Using the surface ionizer, the
1st Fr production experiment was also conducted in 2019. At present, the development of a magneto-optical trap and an atomic
interferometer are in progress.

Members
Director
Susumu SHIMOURA
Scientific Staﬀ
Susumu SHIMOURA (Professor)
Yasuhiro SAKEMI (Professor)
Nobuaki IMAI (Associate Professor)
Kentaro YAKO (Associate Professor)
Taku GUNJI (Associate Professor)

Noritaka SHIMIZU (Project Associate Professor)
Hidetoshi YAMAGUCHI (Lecturer)
Shin’ichiro MICHIMASA (Assistant Professor)
Shinsuke OTA (Assistant Professor)
Hiroki NAGAHAMA (Assistant Professor)

Guest Scientists
Yutaka UTSUNO (Guest Professor)
Daiki NISHIMURA (Guest Associate Professor)

Toshitaka KAJINO (Guest Post Doctoral Associate)

Technical Staﬀ
Yasuteru KOTAKA
Techinical Assistants
Yukimitsu OHSHIRO

Masayoshi YAGYU

Project Research Associates
Masanori DOZONO
Seiya HAYAKAWA

Takashi ABE

Post Doctoral Associates
Shinichi HAYASHI
Daiki SEKIHATA
Keisuke NAKAMURA
Keita KAMAKURA
Jongwon HWANG
Nanru MA

Yusuke TSUNODA
Kota YANASE
Laszlo STUHLLei YANG
Javier MENÉNDEZ

Assistant Teaching Staﬀ
Yuko SEKIGUCHI
Academic Support Staﬀ
Reiko KOJIMA

Chihiro IWAMOTO

Graduate Students
Shoichiro MASUOKA
Noritaka KITAMURA
Keita KAWATA
Hideki SHIMIZU

Rieko TSUNODA
Naoya OZAWA
Shutaro HANAINatsuki SHIMIZU

Administration Staﬀ
Toshio OSUGI
Ikuko YAMAMOTO

Takako ENDO
Yukino KISHI- 402 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

List of Publications & Presentations
Publications[Original papers]
K. Nakano, Y. Watanabe, S. Kawase, H. Wang, H. Otsu, H. Sakurai, S. Takeuchi, Y. Togano, N. Nakamura, M. Maeda, D. S. Ahn,
M. Aikawa, S. Araki, S. Chen, N. Chiga, P. Doornenbal, N. Fukuda, T. Ichihara, T. Isobe, S. Kawakami, T. Kin, Y. Kondo, S. Koyama,
T. Kubo, S. Kubono, M. Uesaka, A. Makinaga, M. Matsushita, T. Matsuzaki, S. Michimasa, S. Momiyama, S. Nagamine, M. Niikura,T. Ozaki, A. Saito, T. Saito, Y. Shiga, M. Shikata, Y. Shimizu, S. Shimoura, T. Sumikama, P. A. Söderström, H. Suzuki, H. Takeda,
R. Taniuchi, J. Tsubota, Y. Watanabe, K. Wimmer, T. Yamamoto, and K. Yoshida, “Isotope production in proton-, deuteron-, andcarbon-induced reactions on 93 Nb at 113 MeV/nucleon,” Phys. Rev. C 100, 044605 (2019).
A. Corsi, Y. Kubota, J. Casal, M. Gómez-Ramos, A. M. Moro, G. Authelet, H. Baba, C. Caesar, D. Calvet, A. Delbart, M. Dozono,
J. Feng, F. Flavigny, J. -M. Gheller, J. Gibelin, A. Giganon, A. Gillibert, K. Hasegawa, T. Isobe, Y. Kanaya, S. Kawakami, D. Kim,
Y. Kiyokawa, M. Kobayashi, N. Kobayashi, T. Kobayashi, Y. Kondo, Z. Korkulu, S. Koyama, V. Lapoux, Y. Maeda, F. M. Marques,
T. Motobayashi, T. Miyazaki, T. Nakamura, N. Nakatsuka, Y. Nishio, A. Obertelli, A. Ohkura, N. A. Orr, S. Ota, H. Otsu, T. Ozaki,
V. Panin, S. Paschalis, E. C. Pollacco, S. Reichert, J. - Y. Rousse, A. T. Saito, S. Sakaguchi, M. Sako, C. Santamaria, M. Sasano,
H. Sato, M. Shikata, Y. Shimizu, Y. Shindo, L. Stuhl, T. Sumikama, Y. L. Sun, M. Tabata, Y. Togano, J. Tsubota, T. Uesaka, Z. H. Yang,
J. Yasuda, K. Yoneda, and J. Zenihiro, “Structure of 13 Be probed via quasi-free scattering,” Phys. Lett. B 797, 134843 (2019).
M. Mazzocco, N. Keeley, A. Boiano, C. Boiano, M. La Commara, C. Manea, C. Parascandolo, D. Pierroutsakou, C. Signorini, E. Strano,
D. Torresi, H. Yamaguchi, D. Kahl, L. Acosta, P. Di Meo, J. P. Fernandez-Garcia, T. Glodariu, J. Grebosz, A. Guglielmetti, Y. Hirayama,
N. Imai, H. Ishiyama, N. Iwasa, S. C. Jeong, H. M. Jia, Y. H. Kim, S. Kimura, S. Kubono, G. La Rana, C. J. Lin, P. Lotti, G. MarquinezDuran, I. Martel, H. Miyatake, M. Mukai, T. Nakao, M. Nicoletto, A. Pakou, K. Rusek, Y. Sakaguchi, A. M. Sanchez-Bentez, T. Sava,
O. Sgouros, V. Soukeras, F. Soramel, E. Stiliaris, L. Stroe, T. Teranishi, N. Toniolo, Y. Wakabayashi, Y. X. Watanabe, L. Yang,
Y. Y. Yang, and H. Q. Zhang, “Elastic scattering for the 8 B and 7 Be + 208 Pb systems at near-Coulomb barrier energies,” Phys. Rev. C
100, 024602 (2019).
H. Wang, H. Otsu, N. Chiga, S. Kawase, S. Takeuchi, T. Sumikama, S. Koyama, H. Sakurai, Y. Watanabe, S. Nakayama, D. S. Ahn,
H. Baba, S. D. Chen, K. Chikaato, M. L. Cortés, N. Fukuda, A. Hirayama, R. Hosoda, T. Isobe, S. Kawakami, Y. Kondo, S. Kubono,
Y. Maeda, S. Masuoka, S. Michimasa, I. Murray, R. Nakajima, T. Nakamura, K. Nakano, M. Nishimura, T. Ozaki, A. Saito, T. Saito,
H. Sato, Y. Shimizu, S. Shimoura, P. A. Söderström, Y. Soudo, X. H. Sun, J. Suwa, D. Suzuki, H. Suzuki, H. Takeda, M. Takechi,
Y. Togano, T. Tomai, H. Yamada, M. Yasuda, and K. Yoshida “Enhancement of element production by incomplete fusion reaction withweakly bound deuteron,” Commun. Phys. 2, Article number 78 (2019).
R. Taniuchi, C. Santamaria, P. Doornenbal, A. Obertelli, K. Yoneda, G. Authelet, H. Baba, D. Calvet, F. Chateau, A. Corsi, A. Delbart,
J. -M. Gheller, A. Gillibert, J. D. Holt, T. Isobe, V. Lapoux, M. Matsushita, J. Menéndez, S. Momiyama, T. Motobayashi, M. Niikura,
F. Nowacki, K. Ogata, H. Otsu, T. Otsuka, C. Peron, S. Peru, A. Peyaud, E. C. Pollacco, A. Poves, J. - Y. Rousse, H. Sakurai,
A. Schwenk, Y. Shiga, J. Simonis, S. R. Stroberg, S. Takeuchi, Y. Tsunoda, T. Uesaka, H. Wang, F. Browne, L. X. Chung, Z. Dombradi,
S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadynska-Klek, Z. Korkulu, S. Koyama, Y. Kubota, J. Lee, M. Lettmann, C. Louchart,
R. Lozeva, K. Matsui, T. Miyazaki, S. Nishimura, L. Olivier, S. Ota, Z. Patel, E. Sahin, C. Shand, P. -A. Söderström, I. Stefan,
D. Steppenbeck, T. Sumikama, D. Suzuki, Z. Vajta, V. Werner, J. Wu, and Z. Y. Xu, “78 Ni revealed as a doubly magic stronghold
against nuclear deformation,” Nature 569, 53 (2019).
N. Paul, A. Obertelli, C. A. Bertulani, A. Corsi, P. Doornenbal, J. L. Rodriguez-Sanchez, G. Authelet, H. Baba, D. Calvet, F. Chateau,
S. Chen,, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama,, T. Motobayashi,
M. Niikura, H. Otsu, C. Peron, A. Peyaud, E. C. Pollacco, J. -Y. Rousse, H. Sakurai, C. Santamaria, M. Sasano, Y. Shiga, D. Steppenbeck, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang, K. Yoneda, T. Ando,, T. Arici, A. Blazhev, F. Browne, A. M. Bruce, R. Carroll,
L. X. Chung, M. L. Cortes,,, M. Dewald, B. Ding, Zs. Dombradi, F. Flavigny, S. Franchoo, F. Giacoppo, M. Gorska, A. Gottardo,
K. Hadynska- Klek, Z. Korkulu, S. Koyama,, Y. Kubota,, A. Jungclaus, J. Lee, M. Lettmann, B. D. Linh, J. Liu, Z. Liu, C. Lizarazo,
C. Louchart, R. Lozeva,, K. Matsui, T. Miyazaki, K. Moschner, S. Nagamine,, N. Nakatsuka, C. Nita, S. Nishimura, C. R. Nobs,
L. Olivier, S. Ota, Z. Patel, Zs. Podolyak, M. Rudigier, E. Sahin, T. Y. Saito,, C. Shand, P. -A. Söderström, I. G. Stefan, T. Sumikama,
D. Suzuki, R. Orlandi, V. Vaquero, Zs. Vajta, V. Werner, K. Wimmer, J. Wu, and Z. Xu, “Prominence of Pairing in Inclusive (p, 2p)
and (p, pn) Cross Sections from Neutron-Rich Nuclei,” Phys. Rev. Lett. 122, 162503 (2019).
S. Michimasa, J. Hwang, K. Yamada, S. Ota, M. Dozono, N. Imai, K. Yoshida, Y. Yanagisawa, K. Kusaka, M. Ohtake, M. Matsushita,
D. S. Ahn, O. Beliuskina, N. Chiga, K. Chikaato, N. Fukuda, S. Hayakawa, E. Ideguchi, K. Iribe, C. Iwamoto, S. Kawase, K. Kawata,
N. Kitamura, S. Masuoka, H. Miyatake, D. Nagae, R. Nakajima, T. Nakamura, K. Nakano, S. Omika, H. Otsu, H. Sakurai, P. Schrock,H. Shimizu, Y. Shimizu, T. Sumikama, X. Sun, D. Suzuki, H. Suzuki, M. Takaki, M. Takechi, H. Takeda, S. Takeuchi, T. Teranishi,
R. Tsunoda, H. Wang, Y. Watanabe, Y. X. Watanabe, K. Wimmer, K. Yako, H. Yamaguchi, L. Yang, H. Yoshida, and S. Shimoura,“OEDO, the energy-degrading beamline at RI Beam Factory,” Prog. Theor. Exp. Phys. 2019, 043D01 (2019).
J. Hwang, S. Michimasa, S. Ota, M. Dozono, N. Imai, K. Yoshida, Y. Yanagisawa, K. Kusaka, M. Ohtake, D. S. Ahn, O. Beliuskina,
N. Fukuda, C. Iwamoto, S. Kawase, K. Kawata, N. Kitamura, S. Masuoka, H. Otsu, H. Sakurai, P. Schrock, T. Sumikama, H. Suzuki,
M. Takaki, H. Takeda, R. Tsunoda, K. Wimmer, K. Yako, and S. Shimoura, “Angle-tunable wedge degrader for an energy-degrading
RI beamline,” Prog. Theor. Exp. Phys. 2019, 043D02 (2019).
S. Takeuchi, T. Nakamura, M. Shikata, Y. Togano, Y. Kondo, J. Tsubota, T. Ozaki, A. Saito, H. Otsu, H. Wang, H. Sakurai, Y. Watanabe,
S. Kawase, D. S. Ahn, M. Aikawa, T. Ando, S. Araki, S. Chen, N. Chiga, P. Doornenbal, S. Ebata, N. Fukuda, T. Isobe, S. Kawakami,
T. Kin, S. Koyama, S. Kubono, Y. Maeda, A. Makinaga, M. Matsushita, T. Matsuzaki, S. Michimasa, S. Momiyama, S. Nagamine,
K. Nakano, M. Niikura, K. Ogata, T. Saito, Y. Shiga, Y. Shimizu, S. Shimoura, T. Sumikama, P. A. Söderström, H. Suzuki, H. Takeda,
R. Taniuchi, M. Uesaka, Y. Watanabe, K. Wimmer, T. Yamamoto, and K. Yoshida, “Coulomb breakup reactions of 93, 94 Zr in inverse
kinematics,” Prog. Theor. Exp. Phys. 2019, 013D02 (2019).

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Z. Elekes, A. Kripko, D. Sohler, K. Sieja, K. Ogata, K. Yoshida, P. Doornenbal, A. Obertelli, G. Authelet, H. Baba, D. Calvet, F. Chateau,
A. Corsi, A. Delbart, J. -M. Gheller, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi, H. Otsu,
C. Peron, A. Peyaud, E. C. Pollacco, J. -Y. Rousse, H. Sakurai, C. Santamaria, Y. Shiga, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang,
K. Yoneda, F. Browne, L. X. Chung, Zs. Dombradi, F. Flavigny, S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadynska-Klek, Z. Korkulu,
S. Koyama, Y. Kubota, J. Lee, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, M. Niikura, S. Nishimura, L. Olivier,S. Ota, Z. Patel, E. Sahin, C. Shand, P. -A. Söderström, I. Stefan, D. Steppenbeck, T. Sumikama, D. Suzuki, Zs. Vajta, V. Werner, J. Wu,
and Z. Xu, “Nuclear structure of 76 Ni from the (p,2p) reaction,” Phys. Rev. C 99, 014312 (2019).
S. Chen, J. Lee, P. Doornenbal, A. Obertelli, C. Barbieri, Y. Chazono, P. Navratil, K. Ogata, T. Otsuka, F. Raimondi, V. Soma, Y. Utsuno,
K. Yoshida, H. Baba, F. Browne, D. Calvet, F. Chateau, N. Chiga, A. Corsi, M. L. Cortes, A. Delbart, J. M. Gheller, A. Giganon,
A. Gillibert, C. Hilaire, T. Isobe, J. Kahlbow, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu,
V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer,
K. Yoneda, N. Achouri, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. -B. Gerst, J. Gibelin, K. I. Hahn,
D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park,D. Rossi, E. Sahin, D. Sohler, P. A. Söderström, S. Takeuchi, H. Tornqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu,
H. Yamada, D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “Quasifree neutron knockout from 54 Ca corroborates arising N = 34 neutron
magic number,” Phys. Rev. Lett. 123, 142501 (2019).
L. Stuhl, M. Sasano, J. Gao, Y. Hirai, K. Yako, T. Wakasa, D. S. Ahn, H. Baba, A. I. Chilug, S. Franchoo, Y. Fujino, N. Fukuda, J. Gibelin,
I. S. Hahn, Z. Halasz, T. Harada, M. N. Harakeh, D. Inomoto, T. Isobe, H. Kasahara, D. Kim, G. G. Kiss, T. Kobayashi, Y. Kondo,
Z. Korkulu, S. Koyama, Y. Kubota, A. Kurihara, H. N. Liu, M. Matsumoto, S. Michimasa, H. Miki, M. Miwa, T. Motobayashi,
T. Nakamura, M. Nishimura, H. Otsu, V. Panin, S. Park, A. T. Saito, H. Sakai, H. Sato, T. Shimada, Y. Shimizu, S. Shimoura,
A. Spiridon, I. C. Stefanescu, X. Sun, Y. L. Sun, H. Suzuki, E. Takada, Y. Togano, T. Tomai, L. Trache, D. Tudor, T. Uesaka, H. Yamada,Z. Yang, M. Yasuda, K. Yoneda, K. Yoshida, J. Zenihiro, and N. Zhang, “Study of spin-isospin responses of radioactive nuclei with thebackground-free neutron spectrometer, PANDORA,” Nucl. Instrum. Methods Phys. Res. B 463, 189–194 (2020).
S. Michimasa, N. Imai, M. Dozono, J. W. Hwang, K. Yamada, S. Ota, K. Yoshida, Y. Yanagisawa, K. Kusaka, M. Ohtake, M. Matsushita,
D. S. Ahn, O. Beliuskina, N. Chiga, K. Chikaato, N. Fukuda, S. Hayakawa, E. Ideguchi, K. Iribe, C. Iwamoto, S. Kawase, K. Kawata,
N. Kitamura, S. Masuoka, H. Miyatake, D. Nagae, R. Nakajima, T. Nakamura, K. Nakano, S. Omika, H. Otsu, H. Sakurai, P. Schrock,H. Shimizu, Y. Shimizu, T. Sumikama, X. Sun, D. Suzuki, H. Suzuki, M. Takaki, M. Takechi, H. Takeda, S. Takeuchi, T. Teranishi,
R. Tsunoda, H. Wang, Y. Watanabe, Y. X. Watanabe, K. Wimmer, K. Yako, H. Yamaguchi, L. Yang, H. Yoshida, and S. Shimoura,“New energy-degrading beamline for in-flight RI beams, OEDO,” Nucl. Instrum. Methods Phys. Res. B 463, 143 (2020).
M. L. Cortés, W. Rodriguez, P. Doornenbal, A. Obertelli, J. D. Holt, S. M. Lenzi, J. Menéndez, F. Nowacki, K. Ogata, A. Poves,
T. R. Rodrguez, A. Schwenk, J. Simonis, S. R. Stroberg, K. Yoshida, L. Achouri, H. Baba, F. Browne, D. Calvet, F. Chateau, S. Chen,
N. Chiga, A. Corsi, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux,
H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun,
Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. -B. Gerst,
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N. Tsunoda, T. Otsuka, A. J. Knapton, G. C. Ball, N. Bernier, C. Burbadge, A. Chester, D. S. Cross, S. Cruz, C. Aa. Diget, T. Domingo,
T. E. Drake, L. J. Evitts, F. H. Garcia, S. Hallam, E. MacConnachie, M. Moukaddam, D. Muecher, E. Padilla-Rodal, O. Paetkau,
J. Park, J. L. Pore, U. Rizwan, J. Smallcombe, J. K. Smith, K. Starosta, C. E. Svensson, J. Williams, and M. Williams, “Shell evolution
approaching the N = 20 island of inversion: Structure of 29 Mg,” Phys. Rev. C 99, 044320 (2019).
F. Flavigny, J. Elseviers, A. N. Andreyev, C. Bauer, V. Bildstein, A. Blazhev, B. A. Brown, H. De Witte, J. Diriken, V. N. Fedosseev,
S. Franchoo, R. Gernhäuser, M. Huyse, S. Ilieva, S. Klupp, Th. Kröll, R. Lutter, B. A. Marsh, D. Mücher, K. Nowak, T. Otsuka,
J. Pakarinen, N. Patronis, R. Raabe, F. Recchia, P. Reiter, T. Roger, S. Sambi, M. Seidlitz, M. D. Seliverstov, B. Siebeck, Y. Tsunoda,
P. Van Duppen, M. Vermeulen, M. Von Schmid, D. Voulot, N. Warr, F. Wenander, and K. Wimmer, “Microscopic structure of coexisting0+ states in 68Ni probed via two-neutron transfer,” Phys. Rev. C 99, 054332 (2019).
T. Shizuma, M. Omer, R. Hajima, N. Shimizu, and Y. Utsuno, “Spin and parity determination of the 3.004 MeV level in 27 Al: Its low-lying
multiplet structure,” Phys. Rev. C 100, 014307 (2019).
B. Abromeit, Vandana Tripathi, H. L. Crawford, S. N. Liddick, S. Yoshida, Y. Utsuno, P. C. Bender, B. P. Crider, R. Dungan, P. Fallon,
K. Kravvaris, N. Larson, R. S. Lubna, T. Otsuka, C. J. Prokop, A. L. Richard, N. Shimizu, S. L. Tabor, and A. Volya, “β-decay of T z= +11/2 isotopes 37 Al and 39 Si; Understanding Gamow-Teller strength distribution in neutron-rich nuclei,” Phys. Rev. C 100, 014323(2019).
L. Kaya, A. Vogt, P. Reiter, M. Siciliano, N. Shimizu, Y. Utsuno, H. -K. Wang, A. Gargano, L. Coraggio, N. Itaco, K. Arnswald,
D. Bazzacco, B. Birkenbach, A. Blazhev, A. Bracco, B. Bruyneel, L. Corradi, F. C. L. Crespi, G. de Angelis, M. Droste, J. Eberth,A. Esmaylzadeh, E. Farnea, E. Fioretto, C. Fransen, A. Gadea, A. Giaz, A. Görgen, A. Gottardo, K. Hadyńska-Klȩk, H. Hess, R. Hirsch,P. R. John, J. Jolie, A. Jungclaus, V. Karayonchev, L. Kornwebel, W. Korten, S. Leoni, L. Lewandowski, S. Lunardi, R. Menegazzo,
D. Mengoni, C. Michelagnoli, T. Mijatović, G. Montagnoli, D. Montanari, C. Müller-Gatermann, D. Napoli, Zs. Podolyák, G. Pollarolo, F. Recchia, J. -M. Régis, N. Saed-Samii, E. Şahin, F. Scarlassara, K. Schomacker, M. Seidlitz, B. Siebeck, P. -A. Söderström,
A. M. Stefanini, O. Stezowski, S. Szilner, B. Szpak, E. Teruya, C. Ur, J. J. Valiente-Dobón, K. Wolf, K. Yanase, N. Yoshinaga, andK. O. Zell, “Isomer spectroscopy in 133 Ba and high-spin structure of 134 Ba,” Phys. Rev. C 100, 024323 (2019).
T. Miyagi, T. Abe, M. Kohno, P. Navrátil, R. Okamoto, T. Otsuka, N. Shimizu, and S. R. Stroberg, “Ground-state properties of doubly
magic nuclei from the unitary-model-operator approach with chiral two- and three-nucleon forces,” Phys. Rev. C 100, 034310 (2019).
Md. S. R. Laskar, R. Palit, S. N. Mishra, N. Shimizu, Y. Utsuno, E. Ideguchi, U. Garg, S. Biswas, F. S. Babra, R. Gala, C. S. Palshetkar,
and Z. Naik, “Structure of the 11/2- isomeric state in 133 La,” Phys. Rev. C 101, 034315 (2020).
M. Hoferichter, P. Klos, J. Menéndez, and A. Schwenk, “Nuclear structure factors for general spin-independent WIMP-nucleus scattering,”
Phys. Rev. D 99, 055031 (2019).
L. W. Iskra, R. Broda, R. V. F. Janssens, M. P. Carpenter, B. Fornal, T. Lauritsen, T. Otsuka, T. Togashi, Y. Tsunoda, W. B. Walters, andS. Zhu, “Revised B(E3) transition rate and structure of the 3− level in 96 Zr,” Phys. Lett. B 788, 396 (2019).
L. Xie, X. F. Yang, C. Wraith, C. Babcock, J. Bieroń, J. Billowes, M. L. Bissell, K. Blaum, B. Cheal, L. Filippin, K. T. Flanagan,
R. F. Garcia Ruiz, W. Gins, G. Gaigalas, M. Godefroid, C. Gorgesk, L. K. Grob, H. Heylen, P. Jönsson, S. Kaufman. M. Kowalska,
J. Krämer, S. Malbrunot-Ettenauer, R. Neugart, G. Neyens, W. Nörtershäuser, T. Otsuka, J. Papuga, R. Sánchez, Y. Tsunoda, and
D. T. Yordanov, “Nuclear charge radii of 62–80 Zn and their dependence on cross-shell proton excitations,” Phys. Lett. B 797, 134805(2019).
E. A. Coello Perez, J. Menéndez, and A. Schwenk, “Two-neutrino double electron capture on 124 Xe based on an eﬀective theory and thenuclear shell model,” Phys. Lett. B 797, 134885 (2019).
C. Hornung, D. Amanbayev, I. Dedes, G. Kripko-Koncz, I. Miskun, N. Shimizu, S. A. S. Andres, J. Bergmann, T. Dickel, J. Dudek,
J. Ebert, H. Geissel, M. Gorska, H. Grawe, F. Greiner, E. Haettner, T. Otsuka, W. R. Plass, S. Purushothaman, A. -K. Rink, C. Scheidenberger, H. Weick, S. Bagchi, A. Blazhev, O. Charviakova, D. Curien, A. Finlay, S. Kaur,W. Lippert, J. -H. Otto, Z. Patyk, S. Pietri,
Y. K. Tanaka, Y. Tsunoda, and J. S. Winfield, “Isomer studies in the vicinity of the doubly-magic nucleus 100 Sn; observation of a new
low-lying isomeric state in 97 Ag,” Phys. Lett B 802, 135200 (2020).

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Y. L. Sun, A. Obertelli, P. Doornenbal, C. Barbieri, Y. Chazono, T. Duguet, H. N. Liu, P. Navrátil, F. Nowacki, K. Ogata, T. Otsuka,
F. Raimondid, V. Somà, Y. Utsuno, K. Yoshida, N. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chenq, N. Chiga, A. Corsi,
M. L. Cortés, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. Togano, T. Uesaka,
K. Wimmer. K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R. -B. Gerst, J. Gibelin, K. I. Hahna,
D. Kima, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. Ma, Cormick, K. Moschner, T. Nakamura,
S. Y. Park, D. Rossi, E. Sahin, D. Sohler, P. -A. Söderström, S. Takeuchi, H. Törnqvista, V. Vaquero, V. Wagner, S. Wang, V. Werner,
X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, and L. Zanetti, “Restoration of the natural E(1/2+1)-E(3/2+1) energy splitting in
Odd-K isotopes towards N = 40,” Phys. Lett. B 802, 135215 (2020).
N. Shimizu, T. Mizusaki, Y. Utsuno, and Y. Tsunoda, “Thick-restart block Lanczos method for large-scale shell-model calculations,”
Comp. Phys. Comm. 244, 372 (2019).
M. L. Cortés, W. Rodriguez, P. Doornenbal, A. Obertelli, J. D. Holt, S. M. Lenzi, J. Menéndez, F. Nowacki, K. Ogata, A. Poves,
T. R. Rodrı́guez, A. Schwenk, J. Simonis, S. R. Stroberg, K. Yoshida, L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château,jS. Chens, N. Chiga, A. Corsi, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota,
V. Lapoux. H. N. Liu, T. Motobayashi. I. Murray, H. Otsu, V. Panin. N. Paul, H. Sakurai. M. Sasano, D. Steppenbeck, L. Stuhl,
Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R. B. Gerst, J. Gibelin, K. I. Hahn, D. Kima, T. Koiwai, Y. Kondo, P. Koseogloue, J. Lee, C. Lehr B. D. Linh, T. Lokotko. M. MacCormick,
K. Moschner. T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, D. Sohler, P. -A. Söderström, S. Takeuchi, H. Toernqviste, V. Vaqueroa,
V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan. Z. Yang, M. Yasuda, and L. Zanetti, “Shell evolution of N = 40 isotones
towards 60 Ca; First spectroscopy of 62 Ti,” Phys. Lett. B 800, 135071 (2020).
V. Manea, J. Karthein, D. Atanasov, M. Bender, K. Blaum, T. E. Cocolios, S. Eliseev, A. Herlert, J. D. Holt, W. J. Huang, Yu. A. Litvinov,
D. Lunney, J. Menéndez, M. Mougeot, D. Neidherr, L. Schweikhard, A. Schwenk, J. Simonis, A. Welker, F. Wienholtz, and K. Zuber,First glimpse of the N = 82 shell closure below Z = 50 from masses of neutron-rich cadmium isotopes and isomers, Phys. Rev. Lett.
124, 092502 (2020).
M. Ciemala, S. Ziliani, F. C. L. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni,
S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Orynczak, E. Clement, S. Coelli, O. Dorvaux, S. Erturk,
G. de France, C. Fransen, A. Goldkuhle, J. Grebosz, M. N. Harakeh, L. W. Iskra, B. Jacquot, A. Karpov, M. Kicinska-Habior, Y. Kim,
M. Kmiecik, A. Lemasson, S. M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million,
C. Muller-Gatermann, V. Nanal, P. Napiorkowski, D. R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci,
B. Wasilewska, O. Wieland, M. Zieblinski, M. Zielinska, A. Atac, D. Barrientos, B. Birkenbach, A. J. Boston, B. Cederwall, L. Charles,
J. Collado, D. M. Cullen, P. Desesquelles, C. Domingo-Pardo, J. Dudouet, J. Eberth, V. Gonzalez, J. Goupil, L. J. Harkness-Brennan,
H. Hess, D. S. Judson, A. Jungclaus, W. Korten, M. Labiche, A. Lefevre, R. Menegazzo, D. Mengoni, J. Nyberg, R. M. Perez-Vidal,
Zs. Podolyak, A. Pullia, F. Recchia, P. Reiter, F. Saillant, M. D. Salsac, E. Sanchis, O. Stezowski, Ch. Theisen, J. J. Valiente-Dobon,
J. D. Holt, J. Menéndez, A. Schwenk, and J. Simonis, “Lifetime measurements of the second 2+ state in neutron-rich 16 C and 20 O as atest of ab initio nuclear structure, Phys. Rev. C 101 021303 (2020).
֯ా༎հ, “Ni ಉҐମʹ͓͚Δ৽‫ͳح‬ม‫ڞܗ‬ଘ‫ݱ‬৅ͱ֩ࢠ഑Ґʹґଘ֪ͨ͠ਐԽͷ‫ڀݚ‬,” ‫ڀݚ֩ࢠݪ‬ୈ 64 ‫ ר‬1 ߸ 25 ท (2019).

[Books]T. Shibata, I. Tanihata, M. Fujiwara, T. Otsuka, and S. Shimoura: “Large-scale investigation of deposited radioactive materials,” Environmental Contamination from the Fukushima Nuclear Disaster, ed., Teruyuki Nakajima, Toshimasa Ohara, Mitsuo Uematsu and Yuichi
Onda, CAMBRIDGE ENVIRONMENTAL CHEMISTRY SERIES, CAMBRIDGE, 2019, pp. 309–323.

[Proceedings]
S. Hayakawa, K. Abe, O. Beliuskina, S. M. Cha, K. Y. Chae, S. Cherubini, P. Figuera, Z. Ge, M. Gulino, J. Hu, A. Inoue, N. Iwasa,
D. Kahl, A. Kim, D. H. Kim, G. G. Kiss, S. Kubono, M. La Cognata, M. La Commara, L. Lamia, M. Lattuada, E. J. Lee, J. Y. Moon,
S. Palmerini, C. Parascandolo, S. Y. Park, D. Pierroutsakou, R. G. Pizzone, G. G. Rapisarda, S. Romano, H. Shimizu, C. Spitaleri,
X. Tang, O. Trippella, A. Tumino, P. Vi, H. Yamaguchi, L. Yang, and N. T. Zhang, “Cross section measurements of the 7 Be(n, p)7 Li
and the 7 Be(n, α)4 He reactions covering the Big-bang nucleosynthesis energy range by the Trojan horse method at CRIB,” Nuclei in
the Cosmos XV (Springer International Publishing), 33–37 (2019).
H. Yamaguchi, S. Hayakawa, L. Yang, H. Shimizu, D. Kahl, and CRIB collaboration, “Study on explosive nucleosynthesis with lowenergy RI beams at CRIB,” Nuclei in the Cosmos XV (Springer International Publishing), 265–268 (2019).
L. Lamia, C. Spitaleri, M. Mazzocco, S. Hayakawa, C. A. Bertulani, A. Boiano, C. Boiano, C. Broggini, A. Caciolli, R. Depalo, F. Galtarossa, G. L. Guardo, M. Gulino, S. Kubono, M. La Cognata, M. La Commara, G. La Rana, M. Lattuada, R. Menegazzo, A. Pakou,
C. Parascandolo, D. Piatti, D. Pierroutsakou, R. G. Pizzone, S. Romano, G. G. Rapisarda, M. L. Sergi, O. Sgouros, F. Soramel, V. Soukeras, E. Strano, D. Torresi, A. Tumino, H. Yamaguchi, F. L. Villante, and G. L. Zhang, “The cosmologically relevant 7 Be(n, α)4 Hereaction in view of the recent THM investigations,” Nuclei in the Cosmos XV (Springer International Publishing), 53–56 (2019).
A. A. Oliva, L. Lamia, G. L. Guardo, C. Spitaleri, S. Cherubini, A. Cvetinovic, G. D’Agata, N. de Sereville, A. Di Pietro, P. Figuera,
M. Gulino, F. Hammache, S. Hayakawa, I. Indelicato, M. La Cognata, M. La Commara, D. Lattuada, M. Lattuada, G. Manicò,
M. Mazzocco, S. Messina, S. Palmerini, R. G. Pizzone, M. L. Pumo, G. G. Rapisarda, S. Romano, M. L. Sergi, N. Soic, R. Spartà, and
A. Tumino, “Study of the neutron induced reaction 17 O(n, α)14 C at astrophysical energies via the Trojan Horse Method,” EPJ Web ofConferences 227, 02007 (2020).
R. G. Pizzone, G. D’Agata, I. Indelicato, M. L. Cognata, P. Figuera, G. L. Guardo, S. Hayakawa, L. Lamia, M. Lattuada, M. Milin,
G. G. Rapisarda, S. Romano, M. L. Sergi, N. Skukan, N. Soic, C. Spitaleri, and A. Tumino, “Fluorine destruction in stars studied via
Trojan horse method,” Proceedings of the 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15),- 408 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

JPS Conf. Proc. 31, 011002 (2020).
S. Ishikawa, N. Iwasa, S. Kubono, K. Asada, D. Guru, S. Hayakawa, K. Hirose, T. Kawabata, K. Kominato, H. Makii, M. Matsuda,
S. Nishimura, K. Nishio, R. Orlandi, and T. Sakakibara, “Experimental study of the 7 Be(n, p1)7 Li* reaction for the cosmologicallithium problem,” Proceedings of the 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15), JPS
Conf. Proc. 31, 011037 (2020).
S. Palmerini, M. L. Cognata, L. Acosta, R. Alba, E. Chavez, S. Cherubini, G. D. Agata, A. D. Pietro, P. Figuera, K. D. L. Rios,
G. L. Guardo, M. Gulino, S. Hayakawa, G. Kiss, M. L. Commara, L. Lamia, C. Maiolino, G. Manico, M. Mazzocco, J. Mrazek,
C. Parascandalo, T. Petruze, D. Pierroutsakou, R. Pizzone, G. Rapisarda, S. Romano, D. Santonocito, R. Sparta, C. Spitaleri, and
A. Tumino, “Measurement of the 27 Al(p, α)24 Mg reaction at astrophysical energies via the Trojan horse method,” Proceedings of the
15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15), JPS Conf. Proc. 31, 011056 (2020).
S. Hayakawa, M. L. Cognata, L. Lamia, H. Shimizu, L. Yang, H. Yamaguchi, K. Abe, O. Beliuskina, S. M. Cha, K. Y. Chae, S. Cherubini,
P. Figuera, Z. Ge, M. Gulino, J. Hu, A. Inoue, N. Iwasa, D. Kahl, A. Kim, D. H. Kim, G. Kiss, S. Kubono, M. L. Commara, M. Lattuada,
E. J. Lee, J. Y. Moon, S. Palmerini, C. Parascandolo, S. Y. Park, D. Pierroutsakou, R. G. Pizzone, G. G. Rapisarda, S. Romano,
C. Spitaleri, X. D. Tang, O. Trippella, A. Tumino, P. Vi, and N. T. Zhang, “Experimental study on the 7 Be(n, p)7 Li and the 7 Be(n, α)4 Hereactions for cosmological lithium problem,” Proceedings of the 15th International Symposium on Origin of Matter and Evolution of
Galaxies (OMEG15), JPS Conf. Proc. 31, 011036 (2020).
H. Shimizu, D. Kahl, H. Yamaguchi, K. Abe, O. Beliuskina, S. M. Cha, K. Y. Chae, A. A. Chen, Z. Ge, S. Hayakawa, N. Imai, N. Iwasa,
A. Kim, D. H. Kim, M. J. Kim, S. Kubono, M. S. Kawag, J. Liang, J. Y. Moon, S. Nishimura, S. Oka, S. Y. Park, A. Psaltis, T. Teranishi,
Y. Ueno, and L. Yang, “Study on 26m Al(p, γ), reaction at the SNe temperature,” Proceedings of the 15th International Symposium on
Origin of Matter and Evolution of Galaxies (OMEG15), JPS Conf. Proc. 31, 011073 (2020).
L. Yang, C. Lin, H. Jia, N. Ma, D. Wang, F. Yang, L. Sun, X. Xu, P. Wen, and F. Zhong, “Reactions with exotic nuclei at near andsub-barrier energies,” EPJ Web of Conferences 223, 01071 (2019).
A. Uchiyama, K. Harada, T. Inoue, H. Kawamura, K. S. Tanaka, M. Itoh, T. Aoki, A. Hatakeyama, Y. Takahashi and Y. Sakemi, “Development of a dual isotope co-magnetometer using laser cooled rubidium toward electron electric dipole moment measurement using
Francium,” Journal of Physics: Conf. Series 1206, 012008 (2019).
M. Hoferichter, P. Klos, J. Menéndez, and A. Schwenk, “Dark-matter-nucleus scattering in chiral eﬀective field theory,” Proceedings of
the 9th International Workshop on Chiral Dynamics, PoS CD2018 (2019) 095.

Presentations[International conferences/workshops]
N. Imai (Oral), “Single particle structure coupled to the second 0+ state in 32Mg,” High resolution gamma ray spectroscopy at RIBF,
T. U. Darmstadt, Germany, April 10–12, 2019.
N. Imai (Invited), “Controlling the motions of two kinds of fermions in a nucleus, a new energy degraded RI beam line OEDO,” Frontier
Session of KPS meeting, Deajon, Korea, April 24–26, 2019.
N. Imai (Oral), “Evaluation of the neutron capture reaction on 79 Se via a surrogate reaction of d(79 Se, p) reaction at OEDO,” The 15th
International Symposium on Origin of Matter and Evolution of Galaxies, Kyoto, July 2–5, 2019.
S. Michimasa (Oral), “Closed-shell nature in neutrons of 54 Ca,” International Nuclear Physics Conference 2019 (INPC2019), Scottish
Event Campus, Glasgow, UK, July 29–August 2, 2019.
M. Dozono (Oral), “Proton-induced reactions on 107 Pd at around 30 MeV/nucleon: First result using slowed-down RI beams at OEDO,”
International Nuclear Physics Conference 2019 (INPC2019), Scottish Event Campus, Glasgow, UK, July 29–August 2, 2019.
J. Hwang (Oral), “Performance of the OEDO beamline,” International Nuclear Physics Conference 2019 (INPC2019), Scottish Event
Campus, Glasgow, UK, July 29–August 2, 2019.
N. Kitamura (Oral), “Structure of 30 Mg studied by in-beam gamma-ray spectroscopy via neutron knockout reactions,” International
Nuclear Physics Conference 2019 (INPC2019), Scottish Event Campus, Glasgow, UK, July 29–August 2, 2019.
N. Kitamura (Oral), “High-resolution spectroscopy of 95–98 Kr,” 8th SUNFLOWER Workshop / HiCARI Workshop, Osaka University,
Osaka, Japan, August 26–28, 2019.
S. Michimasa (Invited), “OEDO status report and development,” OEDO collaboration meeting 2019, Nishina, Saitama, Japan, September
2, 2019.
N. Imai (Invited), “Status report of ImPACT17-02-02,” OEDO collaboration meeting 2019, Nishina, Saitama, Japan, September 2, 2019.
M. Dozono (Invited), “Status report of ImPACT17-02-01,” OEDO collaboration meeting 2019, Nishina, Saitama, Japan, September 2,
2019.
J. Hwang (Invited), “Study of octupole deformation at OEDO,” OEDO collaboration meeting 2019, Nishina, Saitama, Japan, September
2, 2019.
N. Imai (Invited), “Proposal of he surrogate reaction of 130 Sn(n, γ),” OEDO collaboration meeting 2019, Nishina, Saitama, Japan, September 2, 2019.
S. Shimoura (Invited), “OEDO project—Slowing-down beam line in RIKEN RIBF,” XXIII International School on Nuclear Physics andApplication (Varna2019), Varna, Bulgaria, September 23–27, 2019.
S. Michimasa (Invited), “Present status of the OEDO-SHARAQ system,” Expert Meeting on Next-Generation Fragment Separators
2019, GSI, Germany, September 30–October 2, 2019.
S. Shimoura (Invited), “Slowing-down beam line in RIKEN RIBF—OEDO,” 14th Asia-Pacific Physics Conference (APPC2019), Kuching, Malaysia, November 17–22, 2019.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

S. Michimasa (Oral), “Experimental study of neutron shell gap in Calcium-54,” 14th Asia-Pacific Physics Conference (APPC2019),
Kuching, Malaysia, November 17–22, 2019.
S. Ota (Oral), “Research of isoscalar giant monopole resonances using gaseous activetarget,” 14th Asia-Pacific Physics Conference(APPC2019), Kuching, Malaysia, November 17–22, 2019.
N. Imai (Invited), “Shape coexistence of atomic nuclei,” Frontier Session of KPS meeting, KDJ Center, Gwangju, Korea, December
23–25, 2019.
M. Dozono (Invited), “Nuclear astrophysics studies with OEDO,” JSPS/NRF/NSFC A3 Foresight Program “Nuclear Physics in the 21stCentury” Joint Kickoﬀ Meeting, Kobe, Hyogo, Japan, December 6–7, 2019.
S. Ota (invited), “Kτ from ISGMR measurements on and around 132 Sn,” Gordon Research Conference, Nuclear Chemistry, “Exploring
simple structure patterns and the dynamics of nuclei,” New London, NH, US, June 16–21, 2019.
S. Ota (oral), “Giant resonances in Tin-region nuclei studied using gaseous active target,” Vth Topical Workshop on Modern Aspects inNuclear Structure, Bormio, Italy, February 04–09, 2020.
H. Yamaguchi (invited), “Studying astrophysical reactions and nuclear clusters with low-energy RI beams,” 2019 KPS Spring Meeting,Pioneering session: Low energy nuclear science for astrophysics, Daejeon, Korea, April 25, 2019.
H. Yamaguchi (invited), “Experiments on astrophysical reactions with low-energy unstable nuclei beams at CRIB,” The 27th International
Nuclear Physics Conference (INPC 2019), Glasgow, U.K., July 29–August 2, 2019.
H. Yamaguchi (invited), “Nuclear astrophysics with low-energy RI beams,” Nuclear Physics School for Young Scientists (NUSYS-2019),
Lanzhou, China, August 12–17, 2019.
H. Shimizu (poster), “Isomeric 26 Al beam production with CRIB,” NUclear physics School for Young Scientists (NUSYS-2019), Lanzhou,
China, August 12–17, 2019.
H. Yamaguchi (oral), “Activities at the low-energy RI beam separator CRIB,” RIBF Users Meeting 2019, Wako, Saitama, Japan, September 3–4, 2019.
H. Yamaguchi (invited), “Nuclear astrophysics projects at CNS, the University of Tokyo,” International workshop on Origin of Elements
and Cosmic Evolution: From Big-Bang to Supernovae and Mergers (OECE), Beijing, China, November 27–29, 2019.
H. Yamaguchi (oral), “Active target for the TTIK method,” Workshop on RI-beam Spectroscopy by Innovative Gaseous Active Targets,
Osaka, Japan, December 19–20, 2019.
S. Hayakawa (invited), “Experimental study on the 7 Be(n, p)7 Li and the 7 Be(n, α)4 He reactions for cosmological lithium problem,” The
15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15), Kyoto, Japan, July 2–5, 2019.
H. Shimizu (poster), “Study on 26m Al(p, γ) reaction at the SNe temperature,” The 15th International Symposium on Origin of Matter and
Evolution of Galaxies (OMEG15), Kyoto, Japan, July 2–5, 2019
T. Gunji for the ALICE Collaboration (oral), “Recent results in relativistic heavy-ion collisions with the ALICE experiment at the CERNLHC,” 14th Asia-Pacific Physics Conference (APPC 2019), Kuching, Sarawak, Malaysia, November 17–22, 2019.
D. Sekihata for the ALICE Collaboration (Oral), “Light neutral mesons production at the LHC measured by ALICE,” PHOTON 2019
International Conference on the Structure and the Interactions of the Photon, INFN-LNF, Frascati, Italy, 3–7 June 2019.
D. Sekihata for the ALICE Collaboration (Poster), “Study of dielectron production in Pb-Pb collisions at sqrt(sNN ) = 5.02 TeV with
ALICE,” Quark Matter 2019 - the XXVIIIth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions, Wuhan, China,
November 3–9, 2019.
Y. Sekiguchi for the ALICE collaboration (Oral), “Measurement of long-range two- and multi-particle correlations by ALICE,” theXXVIIIth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions, Wuhan, China, November 3–9, 2019.
Y. Sakemi(invited), “Fundamental physics with cold radioactive atoms,” 14th ASIA-PACIFIC PHYSICS CONFERENCE(APPC14),
Kuching, Malaysia, November 20, 2019.
Y. Sakemi(invited), “Fundamental physics with laser cooled atoms,” 36th Mazurian Lakes Conference on Physics (Probing fundamental
laws of nature with exotic nuclei and atoms), Poland, Piaski, September-2, 2019.
Y. Kotaka (Poster), “Development of the calculation method of injection beam trajectory of RIKEN AVF Cyclotron with 4D emittancemeasured by the developed pepper-pot emittance monitor,” 8th International Beam Instrumentation Conference, Malmö, Sweden,
September 8–12, 2019.
N. Shimizu (invited), “Configuration-interaction shell-model calculations for nuclear structure physics,” 11th Symposium on Discovery,
Fusion, Creation of New Knowledge by Multidisciplinary Computational Sciences, Tsukuba International Congress Center, Tsukuba,
Ibaraki, Japan, October 15, 2019.
N. Shimizu (invited), “Level densities of pf-shell nuclei by large-scale shell-model calculations,” 7th Workshop on Nuclear Level Density
and Gamma Strength, Oslo University, Oslo, Norway, May 28, 2019.
T. Abe (oral), “Alpha-cluster structure of light nuclei from no-core Monte Carlo shell model,” RIBF Users Meeting, RIKEN RIBF,
Saitama, Japan, September 3, 2019.
T. Abe (oral), “Alpha-cluster structure from an ab-initio point of view,” RCNP Workshop on RI-beam Spectroscopy by Innovative Gaseous
Active Targets, RCNP, Osaka University, Osaka, Japan, October 20, 2019.
T. Abe (oral), “Intrinsic structure of light nuclei from no-core Monte Carlo shell model,” Pioneer Symposia on Various Manifestations of
Nuclear Structure, KPS Fall Meeting 2019, Gwangju, Korea, October 20, 2019.
K. Yanase (oral), “CP violation in atomic nuclei and Atomic EDM,” International workshop for graduate students and young physicists
on nuclear physics, Peking, University, Beijing, China, November 22–25, 2019.
K. Yanase (oral), “Atomic EDM and CP violation in atomic nuclei,” Nucleon electric dipole moments and spin structure in 2020, KEK,

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Tokai, Japan, January 11, 2020.
T. Abe (poster), “Alpha-cluster structure from the ab-initio Monte Carlo shell model,” International Symposium on Clustering as a Window
on the Hierarchical Structure of Quantum Systems (CLUSHIQ2020), Ryoutiku Bettei, Oita, Japan, January 23, 2020.
J. Menéndez (invited), “Neutrinoless double-beta decay: novel insights on nuclear matrix elements,” International Nuclear Physics Conference (INPC), Glasgow (United Kingdom), July 2019.
J. Menéndez (invited), “Double-beta decay calculations: new tests and opportunities,” the INT Program “Nuclear Structure at the Crossroads,” Seattle (USA), July 2019
J. Menéndez (invited), “Nuclear physics and double-beta decay,” “Massive Neutrinos,” the Wilhelm und Else Heraeus-Seminar Bad
Honnef (Germany), July 2019.
J. Menéndez (invited), “Relating double-beta decay to nuclear properties at hand,” the workshop “Neutrino Nuclear Responses for Double
Beta Decays and Astro Neutrinos (NNR19),” Osaka (Japan), May 2019.
J. Menéndez (invited), “Beta decay in the nuclear shell model: capabilities, limitations, uncertainties,” ECT*Workshop “Precise beta
decay calculations for searches for new physics,” Trento (Italy)
Y. Tsunoda (poster), “Shapes of Sm isotopes studied by Monte Carlo shell model calculations,” 11th Symposium on Discovery, Fusion,
Creation of New Knowledge by Multidisciplinary Computational Sciences, Tsukuba International Congress Center, Tsukuba, Ibaraki,
Japan, October 15, 2019.

[Domestic conferences/workshops]
N. Imai (Oral), ʮr-process ֩ͷதੑࢠั֫൓Ԡ࣮‫͍ͯͭʹݧ‬ʯ, ‫ڀݚݚج‬ձ “‫֩ࢠݪ‬෺ཧͰ๰͙ r-process” ‫౎ژ‬, 2019 ೥ 5 ݄ 22
೔–24 ೔.
N. Imai (Oral), ʮ‫ٯ‬ӡಈֶ 79 Se(d, p) ൓ԠʹΑΔதੑࢠั֫൓Ԡஅ໘ੵͷධՁʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9
݄ 17 ೔–20 ೔.
K. Kawata (Oral), ʮೖࣹ֩ഁࡅ൓ԠʹΑΔ 52 Fe पล֩ͷߴεϐϯΞΠιϚʔͷੜ੒ʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019
೥ 9 ݄ 17 ೔–20 ೔.
R. Tsunoda (Oral), ʮεζಉҐମͷྭ‫ى‬ঢ়ଶͱ૊ΜͩΞΠιόϦοΫΞφϩά‫ڞ‬໐ঢ়ଶʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬,2019 ೥ 9 ݄ 17 ೔–20 ೔.
N. Kitamura (Oral), ʮΠϯϏʔϜΨϯϚઢ֩෼ޫͰ୳Δ 30 Mg ͷ֩ߏ଄ʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17
೔–20 ೔.
N. Imai (Oral), ʮLow-energy RI beam of versatile element; OEDO at RIBFʯ, ATTPC workshop, େࡕ, 2019 ೥ 12 ݄ 19 ೔–20 ೔.
઒ా‫ܟ‬ଠ΄͔ʢ‫ޱ‬಄ൃදʣ, ʮೖࣹ֩ഁࡅ൓ԠʹΑΔ 52 Fe पล֩ͷߴεϐϯΞΠιϚʔͷੜ੒ʯ, ೔ຊ෺ཧֶձ̎̌̍̕೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17 ೔–20 ೔.
OEDO collaboration meeting 2019, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 9 ݄ 2 ೔.
େా৾ี, ԕ౻ོ࢙ʢ‫ޱ‬಄ൃදʣ, ʮେ‫౓ڧ‬ॏΠΦϯϏʔϜরࣹ༻௿ѹΨεΞΫςΟϒඪత CAT ͷ։ൃͱ‫ݱ‬ঢ়ʯ, ϚΠΫϩύλʔϯΨε‫ݕ‬ग़‫( ث‬MPGD)ɾΞΫςΟϒഔ࣭ TPC ߹ಉ‫ڀݚ‬ձ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 12 ݄ 6–7 ೔.
ԕ౻ོ࢙΄͔ʢ‫ޱ‬಄ൃදʣ, ʮେ‫౓ڧ‬ॏΠΦϯϏʔϜরࣹԼͰͷΞΫςΟϒඪత CAT ʹ͓͚ΔΠΦϯόοΫϑϩʔͷ཈੍ʯ, ೔ຊ෺ཧֶձୈ̓̑ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–19 ೔.
ՖҪपଠ࿠΄͔ʢ‫ޱ‬಄ൃදʣ, ʮେ‫ ౓ڧ‬RI ϏʔϜ࣮‫͚͓ʹݧ‬Δߴ଎Ԡ౴ඈ੻‫ݕ‬ग़‫ ث‬SR-PPAC ͷੑೳධՁʯ, ೔ຊ෺ཧֶձୈ̓̑ճ
೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–19 ೔.
ಊԂণഢ΄͔ (‫ޱ‬಄ൃද), ʮΞΠιϚʔಉఆͷͨΊͷΞΫςΟϒετούʔͷ։ൃʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ,໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–19 ೔.
T. Gunji (oral), ʮLHC-ALICE ࣮‫͚͓ʹݧ‬Δ GEM-TPC ߴ౓Խͷ։ൃͱ‫ݱ‬ঢ়ʯ, ୈ 16 ճϚΠΫϩύλʔϯΨε‫ݕ‬ग़‫( ث‬MPGD) ୈ 3
ճΞΫςΟϒഔ࣭ TPC ߹ಉ‫ڀݚ‬ձ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 12 ݄ 6 ೔–7 ೔.
T. Gunji (oral), ʮALICE ࣮‫౓ߴݧ‬Խʹ͓͚Δେ‫ ܕ‬GEM ͱτϦΨʔϨε DAQ ͷ։ൃͱ࣮૷ʯ, ৽ֶज़ྖҬʮΫϥελʔ֊૚ʯʮྔ
ࢠϏʔϜԠ༻ʯ߹ಉ‫ݕ‬ग़‫ث‬ϫʔΫγϣοϓ, ౦๺େֶ, ઋ୆, 2019 ೥ 9 ݄ 20–21 ೔.
T. Gunji (oral), ʮߴΤωϧΪʔॏΠΦϯিಥͷ෺ཧ: ‫ૅج‬ɾ࠷ઌ୺ɾ՝୊ɾల๬ʯ, “কདྷల๬,” ཧ‫ݚ‬γϯϙδ΢Ϝ νϡʔτϦΞϧ‫ڀݚ‬ձ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 8 ݄ 19 ೔–21 ೔.
T. Gunji (oral), ʮFuture ALICE upgrade beyond 2030ʯ, ୈ 36 ճ֦େ൛ Heavy Ion Café, ্ஐେֶ, ઍ୅ా, 2019 ೥ 6 ݄ 22 ೔–23 ೔.
√
D. Sekihata (oral), ʮ֩ࢠର͋ͨΓॏ৺‫ܥ‬ΤωϧΪʔ sNN = 5.02 TeV ཅࢠ-ཅࢠ‫ͼٴ‬Ԗ-Ԗ‫֩ࢠݪ‬িಥʹ͓͚Δதੑதؒࢠͱ௚઀
ޫࢠଌఆʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 17 ೔–20 ೔.
D. Sekihata (Oral), ʮQM2019 Ͱͷϋʔυϓϩʔϒͷ࣮‫ݧ‬త·ͱΊʯ, ʮϙετ QM2019ʯ, ୈ̏̓ճ Heavy Ion Cafe ୈ̏̌ճ Heavy
Ion Pub ߹ಉ‫ڀݚ‬ձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2019 ೥ 12 ݄ 22 ೔.
D. Sekihata (Oral), ʮALICE ࣮‫ ݧ‬TPC ‫ݕ‬ग़‫ث‬ΦϯϥΠϯඈ੻࠶ߏ੒ʹ޲͚ͨ‫ػ‬ցֶशʹΑΔۭؒిՙޮՌͷߴ଎ิਖ਼ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–19 ೔.
ؔ‫ޱ‬༟ࢠ for the ALICE collaboration (Oral), ʮখ͍͞‫͚͓ʹܥ‬Δ௕‫ ཭ڑ‬2 ཻࢠ૬ؔଌఆʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ݄ 16 ೔–19 ೔.
ؔ‫ޱ‬༟ࢠ for the ALICE collaboration (Oral), ʮখ͍͞‫͚͓ʹܥ‬ΔํҐ֯ҟํੑͷϥϐσΟςΟґଘੑʯ, ೔ຊ෺ཧֶձळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄.
খߴ߁র (Oral), ʮཧ‫ ݚ‬AVF αΠΫϩτϩϯೖࣹ‫ܥ‬ͷϏʔϜ‫ي‬ಓ‫ํࢉܭ‬๏ͷධՁͱ 4 ࣍‫ݩ‬Τϛολϯεଌఆ‫ث‬ͷվྑʯ, ୈ 16 ճ೔ຊՃ଎‫ֶث‬ձ೥ձ, ‫౎ژ‬େֶ, ‫౎ژ‬, 2019 ೥ 7 ݄ 31 ೔–8 ݄ 3 ೔.
֯ా༎հʢট଴ߨԋʣ, ʮϞϯςΧϧϩ֪໛‫ʹܕ‬ΑΔϕʔλ่յͷ‫ڀݚ‬ʯ, ‫֩ࢠݪ‬෺ཧͰͭΉ͙ r ϓϩηε, ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ڀݚ‬- 411 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

ॴ, ‫౎ژ‬, 2019 ೥ 5 ݄ 22 ೔.
༄੉޺ଠʢ‫ޱ‬಄ൃදʣ, ʮ‫͚͓ʹ֩ࢠݪ‬Δ CP ରশੑͷഁΕͱి‫ؾ‬૒‫ࢠۃ‬Ϟʔϝϯτʯ, ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬,2019 ೥ 9 ݄ 18 ೔.
ਗ਼ਫଇ޹ʢ‫ޱ‬಄ൃදʣ, ʮ‫࣮ݱ‬త༗ޮ૬‫༻࡞ޓ‬Λ༻͍֪ͨ໛‫ʹܕ‬ΑΔγοϑϞʔϝϯτͷධՁʯ, ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 18 ೔.
֯ా༎հʢ‫ޱ‬಄ൃදʣ, ʮϞϯςΧϧϩ֪໛‫ʹܕ‬ΑΔ Sm ಉҐମͷ‫ܗ‬ঢ়มԽͷ‫ڀݚ‬ʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 18 ೔.
Ѩ෦‫ޱ( ڤ‬಄ൃද), ʮAlpha-cluster structure from the ab-initio Monte Carlo shell modelʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ݄ 18 ೔.
Ѩ෦‫ޱ( ڤ‬಄ൃද), ʮAlpha-cluster structure from ab-initio Monte Carlo shell modelʯ, γϛϡϨʔγϣϯʹΑΔӉ஦ͷ‫ج‬ຊ๏ଇͱਐԽͷղ໌ʹ޲͚ͯ (QUCS 2019), ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ॴڀݚ‬, ‫౎ژ‬, 2019 ೥ 12 ݄ 18 ೔.
֯ా༎հʢ‫ޱ‬಄ൃදʣ, ʮϞϯςΧϧϩ֪໛‫ʹܕ‬ΑΔதॏ֩ͷߏ଄ͷ‫ڀݚ‬ʯ, γϛϡϨʔγϣϯʹΑΔӉ஦ͷ‫ج‬ຊ๏ଇͱਐԽͷղ໌ʹ޲͚ͯ (QUCS 2019), ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ॴڀݚ‬, ‫౎ژ‬, 2019 ೥ 12 ݄ 18 ೔.
ਗ਼ਫଇ޹ʢ‫ޱ‬಄ൃදʣ, ʮ‫֪֩ࢠݪ‬໛‫ͱࢉܭܕ‬ଟ༷ͳม‫ܗ‬όϯυʯ, γϛϡϨʔγϣϯʹΑΔӉ஦ͷ‫ج‬ຊ๏ଇͱਐԽͷղ໌ʹ޲͚ͯ(QUCS 2019), ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ॴڀݚ‬, ‫౎ژ‬, 2019 ೥ 12 ݄ 19 ೔.
༄੉޺ଠʢϙελʔൃදʣ, ʮେ‫ن‬໛֪໛‫ʹࢉܭܕ‬ΑΔ CP ଱༻ੑΛഁΔ૬‫༻࡞ޓ‬ͷ୳ࡧʯ, γϛϡϨʔγϣϯʹΑΔӉ஦ͷ‫ج‬ຊ๏ଇͱਐԽͷղ໌ʹ޲͚ͯ (QUCS 2019), ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ॴڀݚ‬, ‫౎ژ‬, 2019 ೥ 12 ݄ 17 ೔.

[Seminars]
M. N. Harakeh, “Nuclear compression modes from stable to exotic nuclei,” CNS + RIBF NP seminar # 267, RIBF Hall, February 3, 2020.
େ৓޾ޫ (Oral), ʮCNS ΠΦϯ‫ݯ‬ͷ‫ݱ‬ঢ়ʯ, ୈ 17 ճ AVF ߹ಉଧͪ߹Θͤ, ์ࣹઢҩֶ૯߹‫ॴڀݚ‬, ઍ༿, 2019 ೥ 6 ݄ 27 ೔–28 ೔.
খߴ߁র (Oral), ʮཧ‫ ݚ‬AVF ͷ༌ૹ‫࠷ܥ‬దԽͷ‫ݱ‬ঢ়ʯ, ୈ 17 ճ AVF ߹ಉଧͪ߹Θͤ, ์ࣹઢҩֶ૯߹‫ॴڀݚ‬, ઍ༿, 2019 ೥ 6 ݄ 27
೔–28 ೔.
େ৓޾ޫ (Oral), ʮCNS ΠΦϯ‫ݯ‬ͷ‫ݱ‬ঢ়ʯ, ୈ 18 ճ AVF ߹ಉଧͪ߹Θͤ, ཧԽֶ‫ॴڀݚ‬ɾCNS, ࿨ޫ, 2020 ೥ 2 ݄ 18 ೔–19 ೔.
খߴ߁র (Oral), ʮཧ‫ ݚ‬AVF ͷϏʔϜ༌ૹ‫࠷ܥ‬దԽͷ‫ݱ‬ঢ়ʯ, ୈ 18 ճ AVF ߹ಉଧͪ߹Θͤ, ཧԽֶ‫ॴڀݚ‬ɾCNS, ࿨ޫ, 2020 ೥ 2
݄ 18 ೔–19 ೔.
৿Ӭ੖඙ઌੜΛࣱͿձ, ‫ه‬೦ߨԋձʮ̎̍ੈ‫ل‬ͷ෺ཧֶʕӉ஦ɾੜ໋ɾαϒΞτϜʯ, ֶ࢜ձ‫ؗ‬, ઍ୅ా, 2019 ೥ 6 ݄ 2 ೔.

AwardsN. Kitamura, CNSSS18 Young scientist award, ANPhA/AAPPS-DNP award for young scientist for the presentation “characterization ofa tritium target for two-neutron transfer reaction at TRIUMF.”

Others[External review]
External evaluation of CNS, Hongo Campus and CNS Building, January 30–31, 2020.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Partner Institution
Wako Nuclear Science Center, IPNS (Institute of Particle and Nuclear Studies)
KEK (High Energy Accelerator Research Organization)
1. Abstract

The Wako Nuclear Science Center (WNSC) of KEK aims to promote low-energy nuclear physics and nuclear astrophysics research
as well as interdisciplinary studies using short-lived radioactive nuclei. WNSC operates the KEK Isotope Separation System (KISS)
which is an electro-magnetic isotope separator featuring elemental selectivity from the use of resonance laser ionization in a gas
catcher. The KISS facility provides various neutron-rich nuclei via multinucleon transfer reactions. Of particular significance is its
provision of nuclei in the vicinity of the neutron magic number N = 126. Optical and β-γ spectroscopy have been applied to theseneutron-rich nuclear beams, for nuclear structure and nuclear astrophysical studies. Several new developments—a rotating target, adonut-shaped gas cell, and in-jet laser ionization scheme—have been performed to improve the performance of KISS facility. The
WNSC has also developed multi-reflection time of flight mass spectrographs (MRTOF-MS) for precision mass measurements ofshort-lived nuclei in collaboration with the RIKEN SLOWRI team and the Institute of Basic Science (IBS), Korea. After successful
mass measurements in combination with the GARIS-II at RILAC, the existing MRTOF-MS setup has been renewed for use with the
GARIS-II relocated after the ring cyclotron for high precision mass measurements of superheavy nuclides, and additional MRTOF-MS
setups have been placed at KISS and at F11 of the ZeroDegree Spectrometer for comprehensive mass measurements of more than one
thousand nuclides.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Production and manipulation of radioactive isotope beams for nuclear experiments.
Explosive nucleosynthesis (r- and rp-process).
Heavy ion reaction mechanism for producing heavy neutron-rich nuclei.
Development of MRTOF mass spectrographs for short-lived nuclei.
Comprehensive mass measurements of short-lived nuclei including superheavy elements.

3. Summary of Research Activity

The Wako Nuclear Science Center (WNSC) provides low-energy short-lived radioactive ion beams to users from universities
using the KEK isotope separator system (KISS). In FY2019, four experimental programs were carried out at KISS. In terms technicaldevelopments at KISS, an in-jet laser spectroscopy setup for high-precision laser spectroscopy and a multi-reflection time-of-flightmass spectrograph (MRTOF-MS) have been installed and tested online and applied to some physics cases. One was the hyperfine
structure spectroscopy of 194 Os and 196 Os isotopes to determine their isotope shifts. Their half-lives (6 years and 35.9 minutes, respectively) are too long to reasonably determine the resonance wavelengths through decay measurement. However, the mass spectrographallows us to use the ion counting method to identify the resonance by discriminating ions of specific isotope from an isobaric mixture
in the time-of-flight spectrum. Another was β − γ spectroscopy of 192m Os, 192g, 192m Re isotopes of nuclear astrophysical interest. In
this experiment, the KISS beam was shared between the decay station and the MRTOF-MS. During the decay curve measurement at
the decay station, the beam was transferred to the MRTOF-MS to determine the masses and the branching ratios of the isomeric states
and the ground states. The same scheme was also used for the β − γ spectroscopy studies of 186g, 186m, 187g, 197 Ta isotopes.
For the interface between the KISS beams and the MRTOF-MS, a gas cell cooler-buncher (GCCB) plays an essential role. Singlycharged 20 keV ion beams from KISS enter the 30 cm-long gas cell through a 2-mm diameter aperture and are thermalized in 1 mbar
He gas. The thermal ions are extracted by an RF-carpet and transported to a triplet RF quadrupole ion trap before injection into
the MRTOF-MS. We discovered two important phenomena in the GCCB. One is that singly-charged ions are largely converted to
doubly charged ions, which provides a significant gain in the mass resolving power. The other is molecular contaminants in the KISS
beams are totally destroyed in the thermalization process. This feature can be a savior for all low-energy RI-beam facilities whichhave always suﬀered from these molecular contaminations.
In addition to the KISS MRTOF, two more MRTOF setups are presently operated by WNSC in collaboration with RIKENSLOWRI team, one each at the GARIS-II and the BigRIPS facilities of RIKEN RIBF. These will be used for comprehensive massmeasurements of short-lived nuclides including superheavy elements (Z > 103). In FY 2019, the first direct mass measurement ofsuperheavy nuclide (257 Db, Z = 105) has been performed. This setup will be used for precision mass measurements of neutron-rich
moscovium and nihonium isotopes for reliable determination of the atomic numbers as well as the mass numbers. The mass spectrograph at BigRIPS (ZD-MRTOF) is being installed at the end of the BigRIPS+ZeroDegree spectrometer and has already shown ahighest mass resolving power of 570,000 with 9 ms flight time for 39 K+ ions in oﬄine studies. First online commissioning experiment
was scheduled using parasitic beams of in-beam γ experiments in the end of FY2019, however, it was cancelled due to spread of novel
coronavirus disease.

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Members
Group Leader
Michiharu WADA
Researchers
Yutaka WATANABEPeter SCHURY
Sunchan Jeong

Yoshikazu HIRAYAMA
Hiroari MIYATAKE
Marco Rosenbusch

Technical Staﬀ
Yutaka KAKIGUCHI

Michihiro OYAIZU

Visiting Researchers
Hermann WOLNICK (NMSU)
Jun-young MOON (IBS)
Sidong CHEN (HKU)
Wenduo XIAN (HKU)
Hiroshi WATANABE (Beihan University)

Hyun-suk CHOI (Seoul National University)
Jiajian LIU (HKU)
Shuxiong YAN (Jinan University)
Dongsheng HOU (IMP)Student Trainees
Toshitaka NIWASE (PhD. Student, Kyushu Univ.)

Shun IIMURA (PhD. Student, Osaka Univ.)

Assistant
Machiko IZAWA

List of Publications & Presentations
Publications[Original papers]
T. Niwase, M. Wada, P. Schury, H. Haba, S. Ishizawa, Y. Ito, D. Kaji, S. Kimura, H. Miyatake, K. Morimoto, K. Morita, B. M. Rosenbusch,
H. Wollnik, T. Shanley, and Y. Benari, “Development of an “α-TOF” detector for correlated measurement of atomic masses and decay
properties,” Nucl. Instrum. Methods Phys. Res. A 953, 163198 (2020).
Y. Hirayama, Y. X. Watanabe, M. Mukai, P. Schury, M. Ahmed, H. Ishiyama, S. C. Jeong, Y. Kakiguchi, S. Kimura, J. Y. Moon,
M. Oyaizu, J. H. Park, M. Wada, and H. Miyatake, “Nuclear spectroscopy of r-process nuclei using KEK Isotope Separation System,”Nucl. Instrum. Methods Phys. Res. B 463, 425–430 (2020).
M. Rosenbusch, M. Wada, P. Schury, Y. Ito, H. Ishiyama, S. Ishizawa, Y. Hirayama, S. Kimura, T. M. Kojima, H. Miyatake, J. Y. Moon,
T. Niwase, T. Sonoda, A. Takamine, Y. X. Watanabe, and H. Wollnik, “A new multi-reflection time-of-flight mass spectrograph for the
SLOWRI facility,” Nucl. Instrum. Methods Phys. Res. B 463, 184–188 (2020).
M. Mukai, Y. Hirayama, P. Schury, Y. X. Watanabe, M. Ahmed, H. Haba, H. Ishiyama, S. C. Jeong, Y. Kakiguchi, S. Kimura, J. Y. Moon,
M. Oyaizu, A. Ozawa, J. H. Park, H. Ueno, M. Wada, and H. Miyatake, “Development of a multi-segmented proportional gas counterfor β-decay spectroscopy at KISS,” Nucl. Instrum. Methods Phys. Res. B 463, 421–424 (2020).
P. Schury, M. Wada, H. Wollnik, J. -Y. Moon, T. Hashimoto, and M. Rosenbusch, “High-stability, high-voltage power supplies for use
with multi-reflection time-of-flight mass spectrographs,” Rev. Sci. Instrum. 91, 014702 (2020).
S. Michimasa, N. Imai, M. Dozono, J. W. Hwang, K. Yamada, S. Ota, K. Yoshida, Y. Yanagisawa, K. Kusaka, M. Ohtake, M. Matsushita,
D. S. Ahn, O. Beliuskina, N. Chiga, K. Chikaato, N. Fukuda, S. Hayakawa, E. Ideguchi, and S. Shimoura, “New energy-degrading
beamline for in-flight RI beams, OEDO,” Nucl. Instrum. Methods Phys. Res. B 463, 143–147 (2020).
N. Kimura, R. Kodama, K. Suzuki, S. Oishi, M. Wada, K. Okada, N. Ohmae, H. Katori, and N. Nakamura, “Direct determination of theenergy of the first excited fine-structure level in Ba6+ ,” Phys. Rev. A 100, 052508 (2019).
S. Ahmed, E. Altiere, T. Andalib, M. J. Barnes, B. Bell, C. P. Bidinosti, Y. Bylinsky, J. Chak, M. Das, C. A. Davis, F. Fischer, B. Franke,
M. T. W. Gericke, P. Giampa, M. Hahn, S. Hansen-Romu, K. Hatanaka, T. Hayamizu, B. Jamieson, D. Jones, K. Katsika, S. Kawasaki,
T. Kikawa, W. Klassen, A. Konaka, E. Korkmaz, F. Kuchler, L. Kurchaninov, M. Lang, L. Lee, T. Lindner, K. W. Madison, J. Mammei,
R. Mammei, J. W. Martin, R. Matsumiya, E. Miller, T. Momose, R. Picker, E. Pierre, W. D. Ramsay, Y. -N. Rao, W. R. Rawnsley,
L. Rebenitsch, W. Schreyer, S. Sidhu, S. Vanbergen, W. T. H. van Oers, Y. X. Watanabe, and D. Yosifov, “Fast-switching magnet
serving a spallation-driven ultracold neutron source,” Phys. Rev. Accel. Beams 22, 102401 (2019).
H. Wollnik, M. Wada, P. Schury, M. Rosenbusch, Y. Ito, and H. Miyatake, “Time-of-flight mass spectrographs of high mass resolving
power,” International Journal of Modern Physics A 34, 36, 1942001 (2019).
Y. Hirayama, M. Mukai, Y. X. Watanabe, M. Oyaizu, S. C. Jeong, Y. Kakiguchi, P. Schury, M. Wada, and H. Miyatake, “Eﬃcient twocolor two-step laser ionization schemes of λ1 ∼ 250 nm and λ2 = 307.9 nm for heavy refractory elements-Measurements of ionization
cross-sections and hyperfine spectra of tantalum and tungsten,” Rev. Sci. Instrum. 90, 115104 (2019).

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

M. Mazzocco, N. Keeley, A. Boiano, C. Boiano, M. La Commara, C. Manea, C. Parascandolo, D. Pierroutsakou, C. Signorini, E. Strano,
D. Torresi, H. Yamaguchi, D. Kahl, L. Acosta, P. Di Meo, J. P. Fernandez-Garcia, T. Glodariu, J. Grebosz, A. Guglielmetti, Y. Hirayama,
N. Imai, H. Ishiyama, N. Iwasa, S. C. Jeong, H. M. Jia, Y. H. Kim, S. Kimura, S. Kubono, G. La Rana, C. J. Lin, P. Lotti, G. Marquı́nezDurán, I. Martel, H. Miyatake, M. Mukai, T. Nakao, M. Nicoletto, A. Pakou, K. Rusek, Y. Sakaguchi, A. M. Sánchez-Benı́tez, T. Sava,
O. Sgouros, V. Soukeras, F. Soramel, E. Stiliaris, L. Stroe, T. Teranishi, N. Toniolo, Y. Wakabayashi, Y. X. Watanabe, L. Yang,
Y. Y. Yang, and H. Q. Zhang, “Elastic scattering for the 8 B and 7 Be + 2O8 Pb systems at near-Coulomb barrier energies,” Phys. Rev. C
100, 024602 (2019).
S. Ahmed, T. Andalib, M. J. Barnes, C. B. Bidinosti, Y. Bylinsky, J. Chak, M. Das, C. A. Davis, B. Franke, M. T. W. Gericke, P. Giampa,
M. Hahn, S. Hansen-Romu, K. Hatanaka, B. Jamieson, D. Jones, K. Katsika, S. Kawasaki, W. Klassen, A. Konaka, E. Korkmaz,
F. Kuchler, L. Kurchaninov, M. Lang, L. Lee, T. Lindner, K. W. Madison, J. Mammei, R. Mammei, J. W. Martin, R. Matsumiya,
R. Picker, E. Pierre, W. D. Ramsay, Y. -N. Rao, W. R. Rawnsley, L. Rebenitsch, C. A. Remon, W. Schreyer, A. Sikora, S. Sidhu,
J. Sonier, B. Thorsteinson, S. Vanbergen, W. T. H. vanOers, Y. X. Watanabe, and D. Yosifov, “A beamline for fundamental neutron
physics at TRIUMF,” Nucl. Instrum. Methods Phys. Res. A 927, 101–108 (2019).
S. Ahmed, E. Altiere, T. Andalib, B. Bell, C. P. Bidinosti, E. Cudmore, M. Das, C. A. Davis, B. Franke, M. Gericke, P. Giampa, P. Gnyp,
S. Hansen-Romu, K. Hatanaka, T. Hayamizu, B. Jamieson, D. Jones, S. Kawasaki, T. Kikawa, M. Kitaguchi, W. Klassen, A. Konaka,
E. Korkmaz, F. Kuchler, M. Lang, L. Lee, T. Lindner, K. W. Madison, Y. Makida, J. Mammei, R. Mammei, J. W. Martin, R. Matsumiya,
E. Miller, K. Mishima, T. Momose, T. Okamura, S. Page, R. Picker, E. Pierre, W. D. Ramsay, L. Rebenitsch, F. Rehm, W. Schreyer,
H. M. Shimizu, S. Sidhu, A. Sikora, J. Smith, I. Tanihata, B. Thorsteinson, S. Vanbergen, W. T. H. van Oers, and Y. X. Watanabe, “First
ultracold neutrons produced at TRIUMF,” Phys. Rev. C 99, 025503 (2019).
J. Surbrook, M. MacCormick, G. Bollen, M. Brodeur, M. Eibach, K. Gulyuz, A. Hamaker, C. Izzo, S. M. Lenzi, D. Puentes, M. Redshaw,
R. Ringle, R. Sandler, S. Schwarz, P. Schury, N. Smirnova, C. Sumithrarachchi, A. A. Valverde, A. C. C. Villari, and I. T. Yandow,“Precision mass measurements of 44 V and 44m V for nucleon-nucleon interaction studies,” Hyperfine Interact 240, 65 (2019).
N. Kimura, R. Kodama, K. Suzuki, S. Oishi, M. Wada, K. Okada, N. Ohmae, H. Katori, and N. Nakamura, “Direct wavelength measurement of the visible M1 transition in Ba7+ with a novel calibration method,” Plasma and Fusion Research 14, 1201021 (2019).

[Proceedings]
F. Galtarossa, L. Corradi, S. Szilner, E. Fioretto, G. Pollarolo, T. Mijatović, D. Montanari, D. Ackermann, D. Bourgin, S. Courtin, G. Fruet,
A. Goasduﬀ, J. Grebosz, F. Haas, D. Jelavić Malenica, S. C. Jeong, H. M. Jia, P. R. John, D. Mengoni, M. Milin, G. Montagnoli,
F. Scarlassara, N. Skukan N. Soić A. M. Stefanini E. Strano, V. Tokić, C. A. Ur, J. J. Valiente-Dobón, and Y. X. Watanabe, “Light andheavy fragments mass correlation in the 197 Au + 130 T e transfer reaction,” IL NUOVO CIMENTO 42 C, 2–3 (2019).

Presentations[International conferences/workshops]
M. Wada (invited), “Towards precise mass measurements of Nh and Mc isotopes,” 4th International Symposium on Superheavy Elements(SHE2019), Hakone, Japan, December 1–5, 2019.
M. Wada (invited), “SHE-Mass-II setup for direct mass measurement of hot-fusion superheavy nuclides,” 6th International Conference
on the Chemistry and Physics of the Transactinide Elements (TAN2019), Wilhelmshaven, Germany, August 25–31, 2019.
M. Wada (invited), “Antiprotonic atoms with short-lived nuclei,” ECT∗ Antiproton-nucleus interactions and related phenomena, Trento,
Italy, June 17–23, 2019.
M. Wada (invited), “Towards comprehensive mass measurements with MRTOF mass spectrographs at RIKEN RIBF,” 2019 The Korean
Physical Society Spring Meeting, Daejeon, Korea, April 24–26, 2019.
M. Wada (invited), “Symbiotic mass measurement with ZD-MRTOF,” High Resolution Gamma-Ray Spectroscopy at the RIBF, Darmstadt,
Germany, April 10–12, 2019.
H. Miyatake (invited), “KISS Project,” 14th Asia-Pacific Physics Conference, Borneo, Indonesia, November 17–22, 2019.
H. Miyatake (invited), “Recent progress of researches with KISS and MRTOF,” China-Japan Collaboration Workshop on “Nuclear massand life for unraveling mysteries of r-process,” ITP/CAS, Beijing, China, October 9–13, 2019.
H. Miyatake (invited), “Recent progress of researches with KISS and MRTOF,” The 15th International Symposium on Origin of Matterand Evolution of Galaxies (OMEG15), Kyoto, Japan, July 2–5, 2019.
Y. Watanabe (invited), “RI production at low energies “Production of N = 126 nuclei and beyond using multinucleon transfer reactions,”
JSPS/NRF/NSFC A3 Foresight Program—Nuclear Physics in the 21st Century,” Nuclear Structure & Nuclear Reaction Joint Kickoﬀ
Meeting, Kobe, Japan, December 6–7, 2019.
Y. Watanabe (invited), “Recent experimental results of KEK Isotope Separation System (KISS),” 1-day workshop at GSI on new approaches to MNT reaction studies, Darmstadt, Germany, October 23, 2019.
Y. Watanabe (invited), “Recent experimental results of KEK Isotope Separation System (KISS),” The 13th International Conference on
Stopping and Manipulation of Ions and related topics (SMI-2019), Montreal, Canada, July 16–19, 2019.
Y. Watanabe (invited), “Experimental studies of neutron-rich nuclei around N = 126 at KEK isotope separation system,” The IV International Conference on Nuclear Structure and Dynamics (NSD2019), Venice, Italy, May 13–17, 2019.
Y. Watanabe (invited), “Production of N = 126 nuclei and beyond using multinucleon transfer reactions,” Physics between lead anduranium: in preparation of new experimental campaigns at ISOLDE, Leuven, Belgium, April 16–18, 2019.
Y. Hirayama (invited), “Study of nuclear structure in the vicinity of nuclear structure in the vicinity of N = 126 at KISS,” Vth Topical
Workshop on Modern Aspects in Nuclear Structure, Bormio, Italy, February 4–9, 2020.
Y. Hirayama (poster), “Nuclear spectroscopy of r-process nuclei in the vicinity of N = 126 by using KISS,” 27th International Nuclear- 415 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Physics Conference (INPC 2019), Glasgow, UK, July 29–August 2, 2019.
Y. Hirayama (invited), “Nuclear spectroscopy of r-process nuclei in the vicinity of N = 126 at KISS,” Physics between lead and uranium:in preparation of new experimental campaigns at ISOLDE, Leuven, Belgium, April 16–18, 2019. Hirayama P. Schury (invited),“Nuclear physics by multi-reflection time-of-flight mass spectroscopy at WNSC,” 27th International Nuclear Physics Conference (INPC2019), Glasgow, UK, July 29–August 2, 2019.
P. Schury (invited), “Present status and future plans for slow and stopped beams in RIKEN,” The 13th International Conference on
Stopping and Manipulation of Ions and related topics (SMI-2019), Montreal, Canada, July 16–19, 2019.
M. Rosenbusch (oral), “Dynamic ejection-field correction for MRTOF mass spectrometry of SHE using arbitrary mass references fromreliable sources,” 4th International Symposium on Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.
T. Niwase (poster), “Development and first results from a novel “α-TOF” detector used with a multi-reflection time-of-flight mass spectrograph,” 6th International Conference on the Chemistry and Physics of the Transactinide Elements (TAN2019), Wilhelmshaven,
Germany, August 25–31, 2019.
T. Niwase (oral), “Correlation measurement of precision mass and decay properties of nuclei via MRTOF-MS with α-ToF detector,” 4thInternational Symposium on Superheavy Elements (SHE2019), Hakone, Japan, December 1–5, 2019.

[Domestic conferences/workshops]‫ٶ‬෢Ӊ໵ʢ‫ޱ‬಄ൃදʣ, ʮKISS Ͱͷ֩෼ޫ‫ڀݚ‬ʯ, ୹ण໋ RI Λ༻͍ͨ֩෼ޫͱ֩෺ੑ‫ ڀݚ‬VI, ‫౎ژ‬େֶෳ߹‫ྗࢠݪ‬Պֶ‫ॴڀݚ‬, େࡕ෎‫۽‬औ, 2020 ೥ 1 ݄ 16–17 ೔.
‫ٶ‬෢Ӊ໵ʢট଴ߨԋʣ, ʮୈ 7 प‫ݩظ‬ૉՊֶ: ௒ॏ‫ݩ‬ૉͷ෺ཧͱԽֶʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ೥
17–25 ೔.
‫ٶ‬෢Ӊ໵ʢট଴ߨԋʣ, ʮୈ 3 ϐʔΫͱऴᖼྖҬʹର͢Δ࣮‫ݧ‬తΞϓϩʔνʯ, ‫ͭͰ֩ࢠݪ‬Ή͙ r ϓϩηε, ‫౎ژ‬େֶ‫ૅج‬෺ཧֶ‫ݚ‬‫ॴڀ‬, ‫౎ژ‬, 2019 ೥ 5 ݄ 22–24 ೔.
౉ᬒ༟ʢট଴ߨԋʣ, ʮPresent status of KISSʯ, RIKEN, RIBF Users Meeting2019, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 9 ݄ 3–4 ೔.
౉ᬒ༟ʢট଴ߨԋʣ, ʮNuclear researches relevant to r-process with KISS and MRTOFʯ, Ӊ஦ʹ͓͚Δ෺࣭ਐԽ—‫֩ࢠݪ‬ɾ‫ࢠݪ‬ɾ෼
ࢠ—ୈ 1 ճγϯϙδ΢Ϝ, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 8 ݄ 1–2 ೔.
ฏࢁլҰʢ‫ޱ‬಄ൃදʣ, ʮKISS ͰͷΨεδΣοτ಺Ϩʔβʔ‫ڞ‬໐ΠΦϯԽ֩෼ޫʯ, ೔ຊ෺ཧֶձ 2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬,2019 ೥ 9 ೥ 17–25 ೔.
P. Schuryʢ‫ޱ‬಄ൃදʣ, ʮCurrent status and ongoing strategy for MRTOF-MS at WNSCʯ, SSRI-PNS Collaboration Meeting 2019, ཧԽֶ‫ॴڀݚ‬, ࿨ޫ, 2019 ೥ 9 ݄ 4 ೔.
ఉ੉‫ོڿ‬ʢ‫ޱ‬಄ൃදʣ, ʮCorrelation measurement mass and decay properties of short-lived α-decay nuclei via MRTOF with α-TOF
detector (MRTOF+α-TOF Λ༻͍ͨ୹ण໋ α ่յ֩छͷ࣭ྔ-่յಛੑଌఆ)ʯ, ೔ຊ෺ཧֶձୈ 75 ճ೥࣍େձ, ໊‫ݹ‬԰େֶ, ໊‫ݹ‬԰, 2020 ೥ 3 ೥ 16–19 ೔.
ఉ੉‫ོڿ‬ʢ‫ޱ‬಄ൃදʣ, ʮCorrelation measurement of precision mass and decay properties of 207Ra with MRTOF+α-TOFʯ. ೔ຊ์ࣹԽֶձୈ 63 ճ౼࿦ձ (2020), ͍Θ͖࢈‫ۀ‬૑଄‫ؗ‬, ͍Θ͖, 2019 ೥ 9 ݄ 24–26 ೔.
ఉ੉‫ོڿ‬ʢ‫ޱ‬಄ൃදʣ, ʮCorrelation measurement of precision mass and decay properties of 207Ra with MRTOF-MSʯ, ೔ຊ෺ཧֶձ
2019 ೥ळ‫ق‬େձ, ࢁ‫ܗ‬େֶ, ࢁ‫ܗ‬, 2019 ೥ 9 ೥ 17–25 ೔.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Events (April 2019 — March 2020)
RNC
Apr. 20

Wako Open Campus

May. 24

The 25th RBRC Management Steering Committee (MSC)

Jun.24–26

The 5th Nishina Center Advisory Council (NCAC)

Jun. 28

The 18th Program Advisory Committee for Materials and Life Science Researches at RIKEN Nishina Center (ML-PAC)

Jul. 10The 8th Industrial Program Advisory Committee (In-PAC)

Jul.31–Aug.9

Nishina School

Dec.16–18

The 20th Program Advisory Committee for Nuclear Physics Experiments at RI Beam Factory (NP-PAC)

Jan.24

The 19th Program Advisory Committee for Materials and Life Science Researches at RIKEN Nishina Center (ML-PAC)

CNS
Aug. 21–27

18th CNS International Summer School CNSSS19
https://indico2.cns.s.u-tokyo.ac.jp/event/65/- 417 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 53

Press Releases (April 2019−March 2020)
RNC
May. 278

R. Taniuchi, P. Doornenbal, H. Sakurai,Radioactive Isotope Physics Laboratory

Jun. 15

Transverse momentum dependent production cross sections of charged pions, kaonsand protons produced in inclusive e +e− annihilation at √s = 10.58 GeV

R. Seidl, Radiation Laboratory

Jun. 26

Gamma-ray Glow preceding Downward Terrestrial Gamma-ray FlashY. Wada, High Energy Astrophysics Laboratory

Jul. 5Enhancement of element production by incomplete fusion reaction with weakly bound W. He, H. Otsu, Fast RI Data Team, H. Sakurai,
nucleus deuteron
Nuclear Transmutation Data Research Group

Aug. 9Proposal of a 1-ampere-class deuteron single-cell linac for nuclear transmutation

H. Okuno, High-Power Target R&D Team, H.
Sakurai, Nuclear Transmutation Data ResearchGroup

Sep. 12

X-ray pumping of the 229Th nuclear clock isomer

H. Haba, RI Application Research Group

Oct. 18

Quasifree neutron knockout from 54Ca corroborates arising N = 34 neutron magic
number

P. Doornenbal, H. Sakurai, Radioactive Isotope
Physics Laboratory

Nov. 19

Location of the neutron dripline at fluorine and neon

D.S. Ahn, N. Fukuda, N. Inabe, BigRIPS Team,
T. Kubo, Research Instruments Group

Nov. 26

A method of collecting trace amounts of vermilion from artifacts for source estimation
K. Takahashi, Y. Motizuki, Astro-Glaciology
by sulfur isotope (δ34S) analysis: use of sulfur-free adhesive tape to minimize damage
Research Groupto the artifact body during samplingNov. 26

Underlying structure of collective bands and self-organization in quantum systems

T. Otsuka, Nuclear Spectroscopy Laboratory

Nov. 29

Energy of the 229Th nuclear clock isomer determined by absolute γ-ray energy
difference

H. Haba, RI Application Research Group

Mar. 5

Possible lightest Ξ hypernucleus with modern ΞN interactions

E. Hiyama, Strangeness Nuclear Physics
Laboratory, T. Doi, Quantum Hadron Physics
Laboratory

Mar. 13

Swelling of doubly magic 48Ca core in Ca isotopes beyond N = 28

M. Tanaka, Nuclear Spectroscopy Laboratory,
M. Takechi, M. Fukuda, H. Sakurai, Radioactive
Isotope Physics Laboratory

Mar. 17

g-Factor of the 99Zr (7/2+) isomer: monopole evolution in shape coexisting region

Y. Ichikawa, J.-M. Daugas, H. Ueno, Nuclear
Spectroscopy Laboratory

Ni revealed as a doubly magic stronghold against nuclear deformation- 418 -