Ⅴ. EVENTSRIKEN Accel. Prog. Rep. 51 (2018)

ImPACT-OEDO workshop
H. Otsu,∗1 N. Imai,∗2 S. Michimasa,∗2 T. Sumikama,∗1 D. Suzuki,∗1 K. Washiyama,∗3 Y. Watanabe,∗4 and
Y. X. Watanabe∗5
The ImPACT-OEDO workshop1) was held on July
13 and 14, 2017 at the RIKEN Wako campus. The
workshop was jointly organized by the RIKEN Nishina
Center and the Center for Nuclear Study, the University of Tokyo. A total of 70 participants with physics
or engineering backgrounds gathered from institutions
throughout Japan.
The project “Reduction and Resource Recycling ofHigh-level Radioactive Wastes through Nuclear Transmutation” is one of the selected programs of the ImPACT (Impulsing Paradigm Change through Disruptive
Technologies) program under the initiative of the Cabinet Oﬃce. The project has been in operation since 2014
under the collaboration of a number of major research
institutes in Japan, including the RIKEN Nshina Center. Its mission is to develop a new method to transmutate long-lived ﬁssion products (LLFP) that would
otherwise remain highly toxic and to pave a realistic
path toward a sustainable society. At the RIBF andother facilities, the collaboration has been conducting
a number of measurements of reaction rates of nuclei
identiﬁed as LLFPs. In parallel, theoretical studies havebeen widely and actively carried out to interpret the experimental results and extract nuclear data that can beincorporated into state-of-the-art simulation codes. In
addition, FY2017 is marked by the inauguration of the
OEDO beam line at the RIBF. This new beam line iscapable of decelerating fast radioactive isotope beamsof the RIBF down to energies below 50 MeV/nucleon.
With the OEDO beam line, the RIBF will enable reaction measurements of LLFPs over a wide range of energies.
The ImPACT-OEDO workshop was organized to
overview and discuss a wide range of activities related
to nuclear data of LLFPs that have been carried out
in the ImPACT project. Another important goal is tostimulate discussions on future experiments that will be
conducted at the OEDO beam line.
The two-day workshop started with an overview of
the ImPACT program by H. Sakurai (Nishina Center),which was followed by another overview of the subworking group for nuclear data by S. Shimoura (Center
for Nuclear Study). A total of 29 speakers orally presented their activities and future plans in six sessions.
Four sessions were dedicated to recent or on-going studies, and the remaining two were focused on future experiments at the OEDO beam line.

The experiments reported include a series of reaction
studies of LLFPs at the RIBF using a beam of LLFPs
produced from the ﬁssion of a 238 U beam. The reaction
products from spallation or Coulomb breakup reactionsof 107 Pd or 93 Zr were measured in ﬂight. The deduced
cross sections to transmuate LLFPs into stable nuclei orthe inclusive total reaction cross sections were presented.
Another transmutation method under study uses muon
capture. Recent measurements of muon capture rates
and decay branches in the RCNP or in the RIKEN-RAL
facility were presented. These newly aquired data werediscussed in several reports on theoretical studies. One
major topic is related to the integration of the measured
data into widely-used nuclear reaction simulation codessuch as PHITS.2) It was discussed how the nuclear data
should be extracted from the measured data and be inputted into the code, in addition to how the results will
improve the applicability of the simulation to LLFPs.
Another direction in theoretical activities is to further
our understanding of nuclear reactions within the framework of modern nuclear theory, such as the eﬀectivemean-ﬁeld and direct-reaction formalisms, so that morereliable predictions of nuclear data can be made. In addition to these experimental and theoretical studies, afew engineering activities were reported. The talks on
the development of a new isotope separation method tochemically isolate LLFPs and on a new superconducting
cavity as a key device for realizing intense beam acceleration highlighted the interdisciplinary nature of thisproject.
The completion of the OEDO beam line was appreciated by the audience. The development history and successful in-beam commissioning were presented. The planof the ﬁrst physics experiments was discussed. One envisioned experiment is to extract neutron capture crosssections of the LLFP 79 Se from (d, p) reaction cross sections using the so-called surrogate method. The reaction
mechanism behind this method was also discussed. The
other is to measure excitation functions of proton- anddeuteron-induced reactions of 107 Pd. The participantsalso had animated discussions on future experiments using energy-degraded RI beams that will be provided by
the OEDO beam line.
Works discussed in the workshop were supported by
the ImPACT program of the Council for Science, Technology and Innovation (Cabinet Oﬃce, Gouvernment ofJapan).

∗1

References

∗2
∗3
∗4
∗5

RIKEN Nishina Center
Center for Nuclear Study, University of Tokyo
Department of Physics, Tsukuba University
Department of Advanced Energy Enginnering Science,
Kyushu University
Wako Nuclear Science Center, KEK

1) Workshop website: https://indico2.riken.jp/event/25342) K. Niita et al., Radiat. Meas. 41, 1080 (2006).

- 259 -

Ⅴ. EVENTSRIKEN Accel. Prog. Rep. 51 (2018)

Nishina School 2017
T. Motobayashi∗1 and H. Ueno∗2
The 11th Nishina School was held from July 24 toAugust 4, 2017. The school aims at guiding Asian
undergraduate students who are deciding their futureﬁeld of study. A photograph taken at the beginning of
the school is shown in Fig. 1. Students and supervisors from Peking University (PKU) and the Universityof Hong Kong (HKU) joined this 11th School. Highschool students from Phillips Exeter Academy, USA,
along with their teachers, participated in most of the
School programs.

and ﬁnally made presentations on their results. The
reaction they studied was the radiative proton captureby the 12 C nucleus, which is relevant to the CNO cyclehydrogen burning in stars.

Fig. 2. Experimental setup. Proton beams from the Pelletron accelerator hit a carbon target in the small vacuum chamber, and γ rays were measured by the NaI(Tl)scintillator seen in the center of the photograph.

Fig. 1. Photograph of Nishina School 2017 participants.

The 11th School began with self-introductions by thestudents of PKU and HKU, followed by welcome addresses by Hideto En’yo, Nishina Center Director andShunichiro Itakura, RIKEN’s Executive Director. The
ﬁrst week is dedicated mostly to lectures and training
on a few subjects related to the nuclear reaction experiment performed in the second week of the school.
The lectures were on a few basic topics for research,
including overviews of nuclear physics and nuclear astrophysics, the function of particle accelerators, andmethods of radiation measurements. Other lectures
were devoted to radiation safety, paper writing andoral presentation, and issues that researchers may encounter in their future. The subjects of training were
electronic-pulse propagation and radiation detection.
The detectors, electronics, and data acquisition systems to be used in the experiment in the following
week were employed in the training.
The second-week program was focused on the reaction experiment using proton beams from the Pelletron
accelerator at RIKEN Nishina Center. The students
were divided into four teams, which were in charge offour diﬀerent types of measurements. They designed
the experiment by ﬁrst evaluating the feasibility ofmeasurements, then set the detectors around the reaction target, and determined the conditions of beam exposure based on their considerations. After the experiment, they analyzed the experimental data obtained,∗1∗2

Figure 2 shows the experimental setup. Proton
beams with 1 MeV or 2 MeV energy bombarded acarbon target, which stopped the protons to provide
a so-called thick target yield of the 12 C(p,γ)13 N reaction. Two methods were employed for determinationof the resonance yield: detection of “in-beam” γ rays
emitted during the collision of the beam with the carbon target, and measurement of 13 N activities by detecting positron-annihilation photons or the 511-keV γline, known as the “activation” technique.
An example of the γ ray spectrum is shown in Fig. 3.
It is for the “in-beam” measurement with 2 MeV proton beams. Two distinct peaks, which are of relevancein the experiment, are clearly seen. The four teams
could ﬁnally extract the capture cross sections for thetwo resonances in 13 N.

Fig. 3. An example of the γ ray spectra obtained for the“in-beam” measurement for the 12 C(p,γ)13 N reaction
with 2 MeV proton beams. The two γ ray peaks correspond respectively to the two low-lying resonances in
13
N.

We thank all the staﬀ members of the Nishina Center
who participated and helped the Nishina School 2017.

School Master
Chair, Nishina School Steering Committee- 260 -

Ⅴ. EVENTSRIKEN Accel. Prog. Rep. 51 (2018)

IUPAP Meetings and Nuclear Science Symposium at Nihon-Bashi
H. En’yo ∗1
IUPAP Commission 12 (C.12) and Working Group 9(WG.9) meetings were held at the RIKEN Tokyo oﬃce
in Nihon-Bashi, Tokyo on August 29–30, 2017. NihonBashi means Japan-Bridge, and the 113th element nihonium is named after Nihon (Japan or Nippon). As
the name of the place suggests, the oﬃce is in a very
posh central district of Tokyo and in the same building
as Bank of America and Merrill Lynch.
Every two years, the meetings are organized together
with the Nuclear Science Symposium (NSS), in which
recent progress in nuclear physics and related developments are reviewed and discussed in the presenceof invited representatives from national funding agencies worldwide. This year, representatives from South
Africa, Canada, France, Italy, Australia, USA, UK,
Japan, France, and China participated in the symposium.
During the symposium, special in-camera meetings
were held for the representatives of funding agencies. These meetings are meant for representatives
to share the progress in nuclear science and exchange
the status of research in their countries, as well as tosee how their eﬀorts ﬁt into an international framework. The agenda and slides from the symposium
can be found at http://www.triumf.info/hosted/
iupap/icnp/nss2017.html.
Shoji Nagamiya, who chaired the in-camera meetings, presented the following brieﬁng at the end of the
IUPAP WG.9 annual general meeting:(1) The participants of the in-camera meetings recognized that an unprecedented era of nuclear science will be realized, especially with the nextgeneration of rare isotope beam facilities aroundthe world.
(2) They expressed concerns regarding the eﬀect of
open-access policies on large nuclear science laboratories and the implementation of user fees.
(3) They recommended that IUPAP WG.9 may takea more explicit role in international cooperation
for large-scale nuclear science projects.
(4) They recommend that IUPAP WG.9 may positively consider as an “international project” aproject in which the share of responsibilities isdiscussed in IUPAP WG.9 from the beginningof the project by including all the stakeholder
countries.
(5) They also stressed the importance of small-scale
university-based nuclear science laboratories because these are essential training grounds foryoung scientists.
∗1

RIKEN Nishina Center- 261 -

Similar discussions were also made at the IUPAP
WG.9 annual general meeting. Shigeo Koyasu, the executive director of RIKEN, described the future plansfor operations of the Rare Isotope Beam Facility at
RIKEN. He suggested the possibility of asking theusers to bear the cost (collaboration fee) not for electricity, but rather for miscellaneous expenses from thecommon fund for experiments.
There was a wide-ranging discussion of such user
fees in the meeting. A general concern is that, if one
facility implements such charges, other facilities would
then be forced by their funding agencies to follow suit.
This could have serious implications on the scientiﬁc
productivity and mobility of the international community. Some opinions generally supported by the members were as follows: (1) Beam time should be granted
based on scientiﬁc excellence. Any payment for beamtime contradicts this general principle. (2) There isan established tradition among the user community toshare some of the operating costs, but such sharing is
not related to beam time. (3) The host institute must
be very clear about what these user fees can cover. The
funding agencies may prohibit the use of grant funds
to pay these, which might cut oﬀ a facility’s access totalented scientists around the world.
Other issues discussed in IUPAP WG.9 include reports from the Asian Nuclear Physics Association,
the US Nuclear Science Advisory Committee, theFive Year Plan for TRIUMF in Canada, the Nuclear Physics European Collaboration Committee, theLatin-America Community, and the South-African Isotope Facility.

Ⅴ. EVENTSRIKEN Accel. Prog. Rep. 51 (2018)

International conference on nuclear physics at storage rings(STORI2017)
M. Wakasugi∗1
The 10th international conference on nuclear physics
at storage rings (STORI2017) was held at Kanazawa
from November 13 to 18, 2017. The venue was the
Kanazawa theatre (Kageki-za), which is located in thevicinity of the Kanazawa castle. The conference washosted by RIKEN Nishina center and sponsored by
Kanazawa city and Ishikawa prefecture.
(1) Participants and presentations
We had 73 participants in total, and the number ofcountry-speciﬁc participants are listed in Table 1. We
had 61 presentations in total, and the breakdown of
the presentations are as follows: 27 invited talks, 15oral talks, and 19 poster presentations. Figure 1 showsa conference photograph taken at the Kanazawa castle
during the excursion.
(2) Presented topics
The conference started on 0ct. 14th (Tue.), and we
had many active discussions during the week. A wide
range of topics relevant to storage rings and traps were
presented. On Tuesday, M. Steck presented the status of GSI and the rather new facility for decelerated
RI beam, including the newly installed CRYRING, and
B. Juardo presented the topics on neutron induced reaction at CRYRING. The topics that were presented
on physics experiments at ESR/GSI included nuclear
reactions such as a proton scattering using EXL andlaser spectroscopy. There were four talks on the research going on at CERN, namely the status of the
ELENA project, the anti-matter subject at the AD,
the anti-proton annihilation experiment in the PANDA
project, and the ISOLTRAP equipped by a MRTOF.
The current status of the mass measurements using TITAN at TRIUMF was reported. The mass measurements at CSRe/IMP-CAS and the status of the new
project HIAF were presented as ongoing projects in
China. The other mass measurements for exotic nuclei
and some related detector developments at R3/RIKEN
and MRTOF/RIKEN were presented. The RIKEN

RIBF facility and the achievements since its construction were overviewed by H. Sakurai, and the recent results at the SCRIT facility was reported. The statusof the NICA project at JINR/Dubna was reported by
E. Syresin. Atomic physics topics related to the cryogenic electrostatic storage rings at RIKEN and Max
Plank were presented. The high intensity light sourcefor nuclear physics in Romania and the muon g − 2 experiment at Fermi Lab. were also interesting topics.
Experiments on fundamental physics problems such as
EDM and CP violation going on at COSY and RIKEN
were presented. Finally, two theorists, A. Surzhykov
and P. Indelicato, presented the capability of the QED
test in a storage ring.
(3) Poster presentation
We had 19 poster presentations on Friday afternoon, and the international advisory committee gave
poster awards to L. Varga (GSI), B. Wu (IMP), and
H. Arakawa (Saitama U.).
(4) Excursion
In the excursion on Thursday afternoon, we conducted a tour of the Kanazawa castle and the adjacent old town, and organized an experience-based tour
on gold leaf craftwork, which is a traditional speciality in Kanazawa. The participants enjoyed and learned
the history of Kanazawa and the traditional culture ofJapan.
(5) Next STORI2020
In this conference, the international advisory committee decided that the IPM-CSA will host the next
STORI conference, which will be held in 2020 at
Huizhon in China, where there is a planed cite of HIAF.
(6) Acknowledgment
We would like to specially thank the staﬀs ofKanazawa Convention Bureau for their great help inorganizing the conference.

Table 1. Number of country-specific participants.
CountryJapan
Germany
China
Italy
Switzerland
France∗1Participants
37
15
10
2
2
2

Country
CanadaRomania
Russia
U.K.
Korea
Total

Participants
1
1
1
1
1
73
Fig. 1. Conference photograph taken at Kanazawa castle.

RIKEN Nishina Center- 262 -

Ⅴ. EVENTSRIKEN Accel. Prog. Rep. 51 (2018)

International symposium on RI beam physics in the 21st century:
10th anniversary of RIBF
T. Isobe,∗1,∗2 Y.X. Watanabe,∗1,∗6 S. Ota,∗1,∗3 N. Aoi,∗4 N. Imai,∗3 T. Suda,∗5 T. Uesaka,∗2 D. Suzuki,∗2
Y. Ichikawa,∗2 T. Nakamura,∗1,∗7 K. Yoshida,∗1,∗8 and K. Yoneda∗2
The “International symposium on RI beam physics
in the 21st century: 10th anniversary of RIBF” (jointly
hosted by the RIBF User Executive Committee and
RIKEN Nishina Center) was held on 4th and 5th December, 2017. The RI Beam Factory celebrated its
10th anniversary in 2017. Since it started the delivery of RI beams in 2007, the RIBF has successfully
produced a lot of rare isotopes, and completed manyin nuclear physics. In the symposium, recent progressin the physics of unstable nuclei, novel technologies in
RI-beam experiments, and future activities at RIBF
and other RI-beam facilities were discussed.

beam physics was very stimulated in the symposium.
The details of the symposium program can be foundin Ref. 1).
Finally, as a special session by the RIBF user executive committee, a ceremony to present the RIBF
thesis award to two winners was conducted, as shownin Fig. 2, along with a special talk by the recipients. The awards honor the achievements of Dr.
Kazuyuki Sekizawa (Faculty of Physics, Warsaw University of Technology) and Dr. Jin Wu (Argonne National Laboratory) for the Ph.D theses titled “Multinucleon Transfer Reactions and Quasifission Processes
in Time-Dependent Hartree-Fock Theory” (Universityof Tsukuba in 2015) and “Beta-Decay Spectroscopy of
Z = 55–67 Neutron-Rich Nuclei” (Peking University
in 2016), respectively. The RIBF Thesis Award wasco-hosted by UEC and Nishina Center.

Fig. 1. Group photo of the symposium. The symposium
was held at the large conference room of the RIBF
building at RIKEN.

The number of participants was about 120. Figure 1
shows a group photo of the symposium. The program
mainly consisted of four physics categories: Nuclear
Structure, Equation of State, Nuclear Astrophysics,
and Superheavy elements. Four theorists were invited
to give review talks about the progress and perspectives of nuclear structure, nuclear astrophysics, lightnuclear reactions and heavy nuclear reactions based on
the physics outputs from experimental studies curriedout in last decade. Further, presentations about the
future the RI experimental facility were given: FRIB
in USA, NuStar at FAIR in Germany, HIAF in China,
and RISP in Korea. Owing to the condensed topics
and presentations, the discussion regarding future RI
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

RIBF User Group Executive Committee
RIKEN Nishina Center
Center for Nuclear Study, The University of Tokyo
Research Center for Nuclear Physics, Osaka University
Research Center for Electron-Photon Science, Tohoku University
Wako Nuclear Science Center, Institute of Particle and Nuclear Studies, KEK
Department of Physics, Tokyo Institute of Technology
Department of Physics, Kyoto University- 263 -

Fig. 2. Ceremony for RIBF theses award 2017. It was presented to Dr. Jin Wu (left) and Dr. Kazuyuki Sekizawa(right). Certificates and plates were given to winners.

References
1) https://indico2.riken.jp/event/2541/.