ISSN 2186-7968

ELPH

ANNUAL REPORTTOHOKU UNIVERSITY

2016

Editor
MURAMATSU, Norihito
KIKUNAGA, Hidetoshi
MUTO, Toshiya
TOKIYASU, Atsushi

Research Center for Electron Photon Science
Tohoku University
1-2-1 Mikamine, Taihaku, Sendai 982-0826
Japan

Phone: +81, 22-743-3400
Fax:+81, 22-743-3402

Web site: http://www.lns.tohoku.ac.jp/

982-0826

仙台市太白区三神峯1-2-1
東北大学電子光理学研究センター
電話022-743-3400

Fax

022-743-3402

Preface
We are pleased to issue the ELPH Annual Report 2016, which covers scientific andtechnical activities carried out at Research Center for Electron Photon Science (ELPH),
Tohoku University in FY2016 (April, 2016 to March, 2017).
The ELPH has been a part of Joint Usage / Research Centers since FY2011. Joint
Usage / Research Centers (JURC) system was engaged by the Ministry of Education,
Culture, Sports, Science and Technology (MEXT) to encourage and promotecollaborative research passing through the border of respective universities.
This year was the 50th anniversary of the laboratory established in 1966 as former
Laboratory for Nuclear Science (LNS). Prof. Motoharu Kimura, the first director of thelab, was moved to Tohoku University from RIKEN around 1950, not much time passed
since the World War II was over. At that time, the construction of large scaleaccelerators had started in USA or USSR, and then a 600 MeV electron linac(MARK-III) was just completed at Stanford University. Japan really laid waste by thewar, Prof. Kimura had, however, proposed a new conception of laboratory for nuclear
science and related fields to reconstruct Japanese scientific activity. A project of
300 MeV electron linac was approved in 1963, and it was completed in 1967. Nuclear
physics using electron beam was activated immediately and solid state physics using
neutrons as well. The pulsed neutron experiment employing particle accelerator in theworld was initiated at LNS.
The ceremony celebrating 50th anniversary was performed on 17th, November
2016. More than 200 former students in alumni and persons concerned got together andconfabulated with memories of old days. This fantastic night made us a fresh resolve toopen a new era of the laboratory for future human society with the science. We sincerely
ask facility users and related scientific field communities for continuous supports andcooperation.
October, 2017
Director
Hiroyuki Hama

ELPH Annual Report 2016
Contents
I. Topics

The 50th Anniversary of Establishment of Research Center
F. Hinode and N. Muramatsu

1

Public lecture on the 113th element “Nihonium”
T. Suda3

II. Papers

Study of the I = 0 dibaryon resonance d*(2380) via the γd→π0π0d reaction at incident energies
below 0.9 GeV
5
T. Ishikawa, H. Fujimura, H. Fukasawa, R. Hashimoto, Q. He, Y. Honda, T. Iwata,
S. Kaida, H. Kanda, J. Kasagi, A. Kawano, S. Kuwasaki, K. Maeda, S. Masumoto,
M. Miyabe, F. Miyahara, K. Mochizuki, N. Muramatsu, A. Nakamura, K. Nawa,
S. Ogushi, Y. Okada, K. Okamura, Y. Onodera, K. Ozawa, Y. Sakamoto, M. Sato,
H. Shimizu, H. Sugai, K. Suzuki, Y. Tajima, Y. Taniguchi, Y. Tsuchikawa,
H. Yamazaki, R. Yamazaki, and H.Y. Yoshida
Development of Electro-magnetic Calorimeter with Active Absorbers
8
Y. Fujita, Y. Hasegawa, H. Itoh, I. Kanzaki, K. Kotera, E. Naiki, H. Sato, T. Takeshita,
and Y. Yamashita
Current status of preparing the new FOREST experiments at ELPH
11
T. Ishikawa, K. Aoki, H. Fujioka, Y. Honda, T. Hotta, Y. Inoue, K. Itahashi, H. Kanda,
H. Kawai, K. Maeda, Y. Matsumura, M. Miyabe, S. Miyata, N. Muramatsu, T. Nishi,
H. Ohnishi, K. Ozawa, M. Sasagawa, H. Shimizu, R. Shirai, M. Tabata, A.O. Tokiyasu,
Y. Tsuchikawa, and H. Yamazaki
Evaluation of Time Projection Chamber for H-dibaryon search experiment and test ofMulti-gap Resistive Plate Chamber for J-PARC Heavy-Ion project
H. Sugimura, T. Chujo, H. Ekawa, S. Hasegawa, Y. Ichikawa, S. Kimbara, H. Sako,
S. Sato, K. Tanida, J.K. Ahn, S.H. Kim, W.S. Jung, W.J. Choi, J.Y. Lee, R. Aoyama,
T. Ichisawa, H. Kato, T. Nonaka, K. Sato, T. Sugiura, and M. Inaba
Production of 22Na and 24Na with a high-intensity electron beam
K. Ishikubo, T. Ueda, T. Komatsu, K. Tsukada, S. Ninomiya, C. Yoshida

31

42

Large Acceptance Multi-Purpose Spectrometer (LAMPS) Time Projection Chamber (TPC)
Prototype Beam Test
48
H.S. Lee, Y. J. Kim, M. S. Ryu, and J. W. Lee
Performance study of prototype hodoscope for new photon tagging system STB TaggerIIs
M. Iwasa, M. Sasaki, Y. Inoue, T. Ishikawa, H. Kanda, J. Kashiwagura, M. Miyabe,
N. Muramatsu, T. Ono, M. Sasagawa, Y. Seki, R. Shirai, H. Shimizu, Y. Sugihara,
Y. Tajima, A.O. Tokiyasu, H. Wauke, and H.Y. Yoshida54

Photon beam asymmetry measurement for the η photoproduction at SPring-8 BGOegg
experiments
62
N. Muramatsu, T. Hashimoto, J.K. Ahn, W.C. Chang, J.Y. Chen, S. Daté, T. Gogami,
H. Goto, H. Hamano, Q.H. He, K. Hicks, T. Hiraiwa, Y. Honda, T. Hotta, H. Ikuno,
Y. Inoue, T. Ishikawa, I. Jaegle, J.M. Jo, Y. Kasamatsu, H. Katsuragawa, S. Kido,
Y. Kon, S. Masumoto, Y. Matsumura, K. Miki, M. Miyabe, K. Mizutani, T. Nakamura,
T. Nakano, M. Niiyama., Y. Nozawa, Y. Ohashi, H. Ohkuma, H. Ohnishi, T. Ohta,
M. Oka, K. Ozawa, M. Sasagawa, T. Shibukawa, H. Shimizu, R. Shirai, K. Shiraishi,
Y. Sugaya, M. Sumihama, S. Suzuki, S. Tanaka, A.O. Tokiyasu, N. Tomida, N. Tran,
Y. Tsuchikawa, H. Yamazaki, R. Yamazaki, Y. Yanai, T. Yorita, and M. Yosoi
Pulse laser test for the backward Compton scattering at the SPring-8 LEPS beamline
N. Muramatsu1, H. Katsuragawa, T. Nakano, Y. Ohashi, S. Daté, and Y. Orii

66

Electron scattering with stable nuclear targets at SCRIT electron scattering facility
K. Tsukada, K. Adachi, A. Enokizono, T. Fujita, M. Hara, M. Hori, T. Hori,
S. Ichikawa, K. Kurita, T. Ohnishi, T. Suda, T. Tamae, M. Togasaki, N. Uchida,
M. Wakasugi, M. Watanabe, and K. Yamada

68

RI Production for the synthesis of Promethium Endohedral Metallofullerenes by Photon
Activation Method
K. Akiyama, S. Miyauchi, and H. Kikunaga

III. Status Report72

Status of Accelerator Facilities in FY2016
Accelerator group

77

User Support Office Report in FY2016
M. Miyabe and The user support office83

Radiation Safety Report 2016
Radiation Safety Office86

IV. List of Publication89

V. Members of Committees

107

VI. Approved Experiments111

I. Topics

ELPH Annual Report, Tohoku University (2016)1

The 50th Anniversary of Establishment of Research Center
F. Hinode and N. Muramatsu
Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826

The year 2016 marked the 50th anniversary of the establishment of the Laboratory of Nuclear
Science (LNS), the predecessor of the Research Center for Electron Photon Science (ELPH), Tohoku
University. LNS started in 1966 as a shared facility affiliated to the Graduate School of Science. The
300 MeV LINAC constructed in 1967 provided a pulsed electron beam for the wide research fields ofnuclear physics, material science, nuclear chemistry, etc. Simultaneously, the pulsed neutron generationby the high intensity LINAC was started for the first time in the world. This neutron facility leading thepioneering works on the neutron scattering and diffraction experiments had been operated until 1993.
In 1981, the world’s first pulse-stretcher ring was constructed to stretch the pulsed electron beam fromthe LINAC. This ring was used for the variety of nuclear experiments with a continuous electron beam,
and was succeeded to 1.2 GeV stretcher-booster (STB) ring. Since 2009, LNS has been reorganized to
ELPH as an individual research center in Tohoku University. The activities as a Joint Usage / ResearchCenter have begun from 2011. Now tagged photon, electron, and positron beams are available at the
1.3 GeV booster-storage (BST) ring for nuclear / hadron experiments and various detector tests. The
high intensity LINAC of 60 MeV electrons can be also operated together with the BST ring for nuclear
chemistry and electron scattering experiments. The development of a coherent light source in the THz
region has been carried out at the test accelerator facility“t-ACTS”since 2010. Table 1 shows the facility
history for the 50 years. On 17 November, 2016, a ceremony was held celebrating the 50th anniversaryof the establishment. More than 200 people attended to the ceremony, as shown in Fig. 1. The brief
history of the facility including the state of the anniversary ceremony was reported in the reference [1].

References[1]

F. Hinode, H. Hama, J. Particle Accelerator Society of Japan, Vol. 14, No. 2, (2017), 74 (in Japanese)2

Table 1. Facility history for the 50 years
1966
1967
1971
1982
1988
1997
1998
Jul 2002
May 2006
Sep 2006
Feb 2008
Sep 2009
Dec 2009
Mar 2010
Mar 2011
Apr 2011
Dec 2013
Jul 2014
Apr 2015
2016“Laboratory of Nuclear Science (LNS)” was established.
300 MeV Electron LINAC was completed.
Pulsed neutron source was developed.
150 MeV pulse-stretcher ring was completed.
World’s first observation of coherent radiation was carried out.
1.2 GeV Stretcher Booster Ring was completed.
LNS was reorganized as an attached facility to Faculty of Science.
“GeV Gamma-ray Irradiation Building” was completed and hadron experiments began.
Operation of electron-positron test beam lines began.
Magnetic spectrometer “NKS2” was completed.
“Microwave Power Source Building” was completed.
Electromagnetic calorimeter “FOREST” was completed.
LNS was reorganized to “Research Center for Electron Photon Science”.
“Accelerator-based Light Source Building” was completed.
Operation suspended due to the Great East Japan Earthquake.
Approved as a Joint Usage/Research Center for Electron Photon Science.
Operation resumed after recovery from the Great East Japan Earthquake.
Research building was renovated and the “Mikamine Hall” was completed.
Collaborative research division “Condensed Matter Nuclear Reaction” was established.
The 50th anniversary of the establishment.

Fig.1. The 50th anniversary ceremony held on 17 Nov. (photograph: provided by Public Relations & Outreach Office, Faculty of Science, Tohoku University.)

ELPH Annual Report, Tohoku University (2016)3

Public lecture on the 113th element “ Nihonium ”
Toshimi Suda
Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826

On December 10, 2016, a public lecture on the newly discovered 113th element Nihonium was heldat Multidisciplinary Research Building in the Kawauchi campus, Tohoku University. This lecture was
the first one of “Public Science Lecture Series” newly established by Graduate School of Science, Tohoku
University [1]. Since Professors T. Suda and H. Kikunaga of the Research Center for Electron Photon
Science (ELPH) contributed to the discovery, ELPH hosted this event to make this scientific achievement
widely known.
This public lecture was quite timely since it was right after an official announcement by IUPAC(International Pure and Applied Chemistry Association) [2], dated November 30, 2016, on the approval
the name and symbol for the 113th element to be “Nihonium” and “Nh”, respectively. This historicalevent was taken up largely in the press; much public attention has been attracted.
Although the day of the public lecture was unfortunately very cold snowy day, there were more than
150 participants, including students of elementary to high schools, from not only Sendai area but also
Aomori, Akita, Yamagata and Ibaraki prefectures.
The program was started by an introductory lecture on heavy elements such as Nihonium by Professor K. Hagino, Tohoku University, followed by the main lecture by Professor K. Morimoto, RIKEN,
who was the main player of this achievement. He explained exciting stories about the discovery of the113th element Nihonium, and the participants were very enthusiastically listening to his talk. Aftereach lecture, there were many questions from the participants, which clearly showed that everyone hadvery high interest. We were very happy that this public lecture was so successful.

References[1]

http://www.sci.tohoku.ac.jp/mediaoffice/20161213-8808.html (in Japanese)[2]

https://iupac.org/iupac-announces-the-names-of-the-elements-113-115-117-and-118/

4

Fig.1. Event Poster

Fig.2. Professor K. Morimoto

II. Papers

ELPH Annual Report, Tohoku University (2016)

5(ELPH Experiment : #2623, #2640, #2655, #2694, #2710)

Study of the I = 0 dibaryon resonance d∗(2380) via theγd → π 0π 0d reaction at incident energies below 0.9 GeV
T. Ishikawa1 , H. Fujimura1 , H. Fukasawa1 , R. Hashimoto1 , Q. He1 ,Y. Honda1 , T. Iwata2 , S. Kaida1 , H. Kanda3 , J. Kasagi1 , A. Kawano4 ,S. Kuwasaki1 , K. Maeda3 , S. Masumoto5 , M. Miyabe1 , F. Miyahara1 ,K. Mochizuki1 , N. Muramatsu1 , A. Nakamura1 , K. Nawa1 , S. Ogushi1 ,Y. Okada1 , K. Okamura1 , Y. Onodera1 , K. Ozawa6 , Y. Sakamoto4 , M. Sato1 ,H. Shimizu1 , H. Sugai1 , K. Suzuki1 , Y. Tajima2 , Y. Taniguchi1 ,Y. Tsuchikawa1 , H. Yamazaki1 , R. Yamazaki1 , and H.Y. Yoshida2
1

Research Center for Electron Photon Science (ELPH), Tohoku University, Sendai 982-0826,
Japan
2

Department of Physics, Yamagata University, Yamagata 990-8560, Japan
3

4

Department of Physics, Tohoku University, Sendai 980-8578, Japan

Department of Information Science, Tohoku Gakuin University, Sendai 981-3193, Japan
5

6

Department of Physics, University of Tokyo, Tokyo 113-0033, Japan

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization(KEK), Tsukuba 305-0801, JapanThe total cross section was measured for the γd → π 0 π 0 d reaction at incident energies below 0.92

GeV for the first time using the FOREST detector at ELPH. No clear resonance-like behavior was observed in the excitation function for Wγd = 2.38–2.61 GeV, where the d∗ (2380) dibaryon resonanceobserved at CELSIUS and COSY was expected to appear. The measured excitation function was consistent with the existing theoretical calculation. The upper limit of the total cross section was foundto be 0.034 µb for the dibaryon resonance at Wγd = 2.37 GeV (90% confidence level). The details aredescribed in a published paper: T. Ishikawa et al., Phys. Lett. B 772, 398 (2017).

§ 1. Introduction

The search for non-strange dibaryon bound/resonance states has a long history. The dibaryon stateis of interest, which can be a molecule consisting of two baryons or a spatially compact hexaquark object. The d∗ (2380) resonance observed in the pn-collision reactions by the CELESIUS/WASA and WASAat-COSY collaborations [1, 2] may be attributed to an isoscalar ∆∆ quasi-bound state D03 , predicted by

Dyson and Xuong [3]. The s-channel photoproduction γd → π + π − d and γd → π 0 π 0 d reactions are

expected to be of value to get a clue for the size of the d∗ (2380) resonance. The γd → π + π − d reac-tion was studied by the JLAB/CLAS collaboration, and their preliminary result does not show a peakcorresponding to the d∗ (2380) resonance [4]. We investigated the other γd → π 0 π 0 d reaction to study

photoproduction of the d∗ (2380) resonance.

6§ 2. Summary

The γd → π 0 π 0 d reaction was experimentally investigated at the Research Center for Electron

Photon Science (ELPH), Tohoku University, Japan. The incident photon beam ranged from from 0.57 to
0.88 GeV ??. The γd center of mass energy Wγd corresponding the incident energy was covered from
2.38 to 2.61 GeV. The the target used in the experiments was 45.9-mm-thick liquid deuterium. The
kinetic variables for all the final-state particles (γγγγd) were measured using the FOREST detector [7].
A kinematic fit with six constraints was applied for the event selection of the γd → π 0 π 0 d reaction. The

required constraints were energy and three-momentum conservation between the initial and final states
and two γγ invariant masses (the neutral-pion mass). Events in which the χ2 probability is higher than
0.4 are selected to prevent contamination from the background processes. Fig. 1 shows the total crosssection σ as a function of Wγd . No clear resonance-like behavior was observed in the excitation function
near Wγd = 2.38 GeV, where the d∗ (2380) dibaryon resonance was expected to appear. The measured

excitation function was consistent with the existing theoretical calculation for this reaction [8]. The
details of the explanations and discussions are described in Ref. [9].
0.1
0.09

0.07
0.06
0.05
0.04

d*(2380)

Total cross section σ (µ b)

0.08

0.03
0.02
0.01
0

theoretical calculation
systematic error
2375 2400 2425 2450 2475 2500 2525 2550 2575 2600
Wγ d (MeV)

Fig.1. Total cross section σ as a function of Wγd together with the theoretical calculation by Fix
and Arenhövel [8].

Acknowledgments
The authors express their gratitude to the ELPH accelerator staff for stable operation of the accelerators in the FOREST experiments. They also acknowledge Mr. K. Matsuda, Mr. K. Nanbu, and
Mr. I. Nagasawa for their technical support. One of the authors (TI) thanks Prof. H. Clement andDr. M. Bashkanov for fruitful discussions for event selection including the deuteron identification. This
work was supported in part by the Ministry of Education, Culture, Sports, Science and Technology,

7Japan through Grants-in-Aid for Scientific Research (B) No. 17340063, for Specially Promoted ResearchNo. 19002003, for Scientific Research (A) No. 24244022, for Scientific Research (C) No. 26400287, andfor Scientific Research (A) No. 16H02188.

References[1]

M. Bashkanov et al. (CELSIUS/WASA collaboration): Phys. Rev. Lett. 102, 052301 (2009).

[2]

P. Adlarson et al. (WASA-at-COSY collaboration): Phys. Rev. Lett. 106, 242302 (2011).

[3]

F.J. Dyson and N.-H. Xuong: Phys. Rev. Lett. 13, 815 (1964).

[4]

R.A. Schumacher: talk at Meson in Nucleus 2016 (MIN16) (2016);[5]

MIN16 website: ⟨http://www2.yukawa.kyoto-u.ac.jp/~min2016/⟩.
T. Ishikawa et al., Nucl. Instrum. Meth. A 622, 1 (2010)[6]

T. Ishikawa et al., Nucl. Instrum. Meth. A 811, 124 (2016).

[7]

T. Ishikawa et al., Nucl. Instrum. Meth. A 832, 108 (2016).

[8]

A. Fix, H. Arenhövel: Eur. Phy. J. A 25 ,115 (2005).

[9]

T. Ishikawa et al.: Phys. Lett. B 772, 398 (2017).

8

ELPH Annual Report, Tohoku University (2016)(ELPH Experiment : #2761)

Development of Electro-magnetic Calorimeterwith Active Absorbers
Y.Fujita, Y. Hasegawa, H. Itoh, I.Kanzaki, K.Kotera, E. Naiki, H.Sato, T.Takeshita,
and Y.Yamashita
Faculty of Science, Shinshu University, Matsumoto, JapanAn electro-magnetic calorimeter dedicated to measure the incident position and angle with active
absorber is developed and tested with electron beams. The calorimeter consists of active absorbermade of lead glass and scintillator strips with wave length shifting fibers is constructed. We tested
its performance to the electrons at ELPH beam at Tohoku University. The performance and theresults are presented.

§1. Introduction
We are developing a fully active electromagnetic (EM) calorimeter at low energy, which consistsof sandwich calorimeter of active absorber and fine segmented sensitive scintillator. The
calorimeter could measure the photon and electron energy with as good as the lead glass
calorimeter, say 5% of over square root E. Furthermore it can measure the incident angle of photon
and electron with good position resolution. Such an EM calorimeter could be applied for many
experiments with both energy resolution and position/angle resolutions are mandatory. The
performances have been verified with the electron beam at ELPH, Tohoku University.

§2. EM calorimeter and experimental setup
The active absorber EM calorimeter has been introduced in order to improve both energy
resolution and position/angle resolution for photons. The calorimeter detector system is shown in
Figure 1.
It is composed of sandwich structure of the lead glass absorber layer as an active heavy material
and fine segmented scintillator strip layer [1]. The size of a lead glass block is 334 cm3 and readout the Cherenkov light by a MPPC of 33 mm2 [2]. The lead glass unit has been tested by muonsand resulted about 10 photo-electrons (p.e.) / 4 cm passing a lead glass block. We prepared there
lead glass layers, each consist of 33 blocks. There are three scintillator strip layers of X-Y
configuration with nine strips behind the lead glass layers. We set a large lead glass of 121225
cm3 for a tail catcher. A long scintillator strip of 1 cm  18 cm has been employed for the strip layer
with WLSF (Wave Length Shifting Fiber) read out by a MPPC of 11 mm2. The tail catcher has
been read out by a 1212 mm2 MPPC. There is a pair of crossing trigger scintillator strips in frontof the detector to define the beam timing which are also read by MPPCs.

9

EBUs

Figure 1: Schematic view of the active absorber EM calorimeter and its setup at ELPH electron
beam. From left to right, trigger counters, three layers of lead glass active absorber and scintillator
strip and a tail catcher. Each units had been attached a photo-sensor MPPC and read by EASIROC
modules.

All the signals from MPPCs in total 83 channels are read by three EASIROC modules which had
been developed for the MPPC read out through the ether-net [3].

§3. Results
Here we show some results of the active absorber calorimeter tested at ELPH 2016.
(1) The EM shower position distributions are shown in Figure 2-a, with taking information fromthe scintillator strip layers and without it. Slight improvement to the position resolution is seenfrom 15 mm to 13 mm.
(2) The angle resolutions are shown in Figure 2-b with taking information from the scintillator strip
layers and without it. The incident beam angles were changed from 0 to 5 degree. Slight
improvement is seen from 9 degree to 8 degree.
Further analysis is going on.

§4. Conclusion
A sandwich type EM calorimeter has been constructed and tested. A new feature for the detector
is using active absorber with segmentation. The improvements for measurements of the EM shower
position and angle were verified.

10

Acknowledgement
The authors thank the ELPH accelerator staff for providing the primary electron beam with goodquality. They are grateful to M. Miyabe for his technical support in preparation for themeasurements.

References[1] SF6W lead glass employed at TOPAZ , Kawabata et. al. NIM A 270(1988) 11.
[2] MPPC trade mark of Hamamatsu Photonics CO.
[3] A master thesis by Naoki Ishijima, Osaka University, 2014.

Figure 2-a (left) and Figure 2-b (right): Figure 2-a shows the EM shower position measurementwith (red line) and without (blue line) strip information, where energy weighted mean of EM
showers are considered. Figure 2-b shows the incident angle distribution measured with (red line)
and without (blue line) strip information, where linear fitting of all position information weretaken into account.

ELPH Annual Report, Tohoku University (2016)11(ELPH Experiment : #2803, #2844)

Current status of preparing the new FOREST experiments
at ELPH
T. Ishikawa1 , K. Aoki2 , H. Fujioka3 , Y. Honda1 , T. Hotta4 , Y. Inoue1 ,K. Itahashi5 , H. Kanda4 , H. Kawai6 , K. Maeda7 , Y. Matsumura1 , M. Miyabe1 ,S. Miyata8 , N. Muramatsu1 , T. Nishi5 , H. Ohnishi1 , K. Ozawa2 ,M. Sasagawa1 , H. Shimizu1 , R. Shirai1 , M. Tabata6 , A.O. Tokiyasu1 ,Y. Tsuchikawa9 , and H. Yamazaki1
1Research Center for Electron Photon Science (ELPH), Tohoku University, Sendai 982-0826,
Japan

2

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization(KEK), Tsukuba 305-0801, Japan
3

4

Department of Physics, Kyoto University, Kyoto 606-8502, Japan

Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki 567-0047, Japan
5

Nishina Center for Accelerator-Based Science, RIKEN, Wako 351-0198, Japan
6
7

Department of Physics, Tohoku University, Sendai 980-8578, Japan

8
9

Department of Physics, Chiba University, Chiba 263-8522, Japan

Department of Physics, University of Tokyo, Tokyo 113-0033, Japan

Department of Physics, Nagoya University, Nagoya 464-8602, JapanThe next-generation FOREST experiments are planed to reveal the non-perturbative QCD phenomena. The main objective of the first experiment is to determine low-energy S-wave ηn scatteringparameters using the γd → pηn reaction. The photon beam with energies around 940 MeV can give therecoilless condition of η mesons by detecting the protons at 0◦ . The effects of the the final-state ηn in-teraction must be enhanced due to the small relative momentum between the η meson and the residual
neutron. We placed a bending magnet, which was transported from KEK, behind the FOREST detector
to measure the forward emitted protons. The Λn interaction can be studied using the γd → K + Λnreaction detecting the K + mesons at 0◦ in the same experimental setup. And the similar experimen-

tal setup can be used for an experiment to search for η-mesic nuclei, which are good probes to explore
the properties of a nucleon resonance N (1535)S11 in the nuclear medium. It should be noted that theresonance is speculated to be the chiral partner of the nucleon.
We succeeded the excitation and ARCNET control of the bending magnet BLC for the forward
spectrometer using the dedicated power supply QC1LE. The performance tests of the new detectors, two
drift chambers, plastic-scintillator hodoscope, and SF5 lead-glass Cherenkov counters, for the forward
spectrometer were made using the positron beams for testing detectors at ELPH. Commissioning of theforward spectrometer with these detectors was successfully made using the liquid hydrogen target fromMay 22 to May 31 in 2017. In this report, the preparation for the new FOREST experiment is presented.

12§ 1. Introduction

The interaction between hadrons is fundamental and important in the non-perturbative domain ofquantum chromodynamics (QCD), which is the fundamental theory of the strong interaction. Although
the interaction between hadrons is described in principle by quark and gluon dynamics, little is known
for the QCD solutions due to the large running QCD coupling constant at low energies.
Among the two-body dynamics of hadron-hadron systems, the interaction between the η meson andnucleon (N ) is not well known [1] although the interaction is found to be attractive. This is because neither direct ηN scattering experiments nor X-ray measurements from η-mesic atoms can be performed
due to the neutral and unstable nature of the η meson. The low-energy ηN interaction is describedusing the scattering length aηN and effective range rηN in an effective-range expansion of the S-wave
phase shift:k cot δ(k) =

1
aηN

+

1
rηN k2 + O(k4 ).
2(1)

It should be noted that positive and negative aηN values correspond to attractive and repulsive ηNinteractions in this definition, respectively.
Although the imaginary part of aηN (Im[aηN ]) is found to be ∼ 0.26 fm for different analyses, its

real part (Re[aηN ]) is scattered in a wide range from 0.2 to 1.1 fm [2, 3]. Fig. 1 shows the summaryof the obtained imaginary and real parts of aηN taken from Ref. [1]. The Re[aηN ] value is importantand sensitive to the pole position of the N (1535)S11 resonance [4]. It is the lowest excited state of thenucleon with a spin of 1/2 and negative parity, and speculated to be the chiral partner of the nucleon.
The pole is known to be near the ηN threshold but its accurate position is still uncertain. The Re[aηN ]value also affects the existence of exotic η-mesic nuclei [1], which reveal the properties of N (1535)S11
in the nuclear medium since it strongly couples to ηN . In addition, the Re[aηN ] value is also related tothe η-η ′ mixing angle [5].
In many theoretical papers, the aηN values have been extracted using a combined analysis from thedifferential and total cross sections for the πN → ηN transition and γN → ηN photoproduction reac-

tions together with πN → πN scattering and γN → πN photoproduction reactions. As a consequenceof the optical theorem, similar Im[aηN ] values have been obtained in the analyses. A large ambiguity

exists in the determination of the Re[aηN ] value because the reactions used in the aηN analyses do notenhance the effect of the ηN → ηN scattering amplitude so far. Thus we propose the γd → ηpn reaction
to determine aηN at a certain kinematics, which enhances the ηN scattering effect.

A possibility of the precise determination of aηN from the γd → ηpn reaction was first investigatedby Sibiritsev et al. [8] and followed by Fix and Arenhövel [9]. The opposite conclusions for the resolving power of the Re[aηN ] value from the experimental data are shown in these works. However, thekinematics in these pioneering works is near the threshold (Eγ < 0.7 GeV). The contribution from thefirst-order ηN rescattering are not well-separated from the others. We will show the ideal condition to
extract aηN from the γd → ηpn reaction in the next section.

13
1.2
coupled channel
chiral unitary
final state interaction
meson exchange

Im aηN (fm)1chiral perturbation
effective Lagrangian
K-matrixl
others

0.8

0.6

0.4

0.2

0

0

0.2

0.4

0.6

0.8

1

1.2

Re aηN (fm)Fig.1. Imaginary and real parts of the ηN scattering length aηN [1]. The different markers
indicate the different methods to provide the values. All the analyses seem to have asmall effect of the ηN → ηN scattering amplitude.The open circle (red) represent theresult from the dynamical coupled-channels analysis [6, 7].

§ 2. Proposed γd → pηn reaction

To determine aηN , we plan to measure the differential cross sections for the γd → pηn reaction [10]at the Research Center for Electron Photon Science (ELPH), Tohoku University, using the photon beamwith energies around 0.94 GeV [11, 12] and detecting the protons at 0◦ . The bremsstrahlung photon
beam at ELPH covers the energies from 0.82 to 1.26 GeV. Fig. 2 shows the expected diagram of the
proposed reaction. The incident photon bombards the proton in the deuteron and produces a (virtual)η meson with a very low momentum. The scattered proton from the reaction is detected at 0◦ having
a large momentum close to that of the photon beam. At this kinematics, an η meson is likely to be
produced almost at rest with respect to the residual neutron, being expected to strongly interact with it.
The forward-going proton has a large momentum, and little chance to interact with η or neutron. The
characteristics of this diagram are discussed below.
We will select the events in which the incident energy is approximately 0.94 GeV and the proton(with a momentum around 0.94 GeV/c) is detected at 0◦ . This kinematics satisfies the recoilless conditionof the produced η mesons. Fig. 3 shows the recoil momentum of η mesons for the elementary γp → ηpreaction for the free proton target. The incident photon energy of 0.932 GeV can produce η mesons at
rest in the laboratory frame. The ideal low-energy ηn scattering is expected to take place at the incident
photon energy around 0.94 GeV taking into account the binding energy of the deuteron.
The forward proton has a very large momentum, and the relative momentum between the proton

14~940 MeV/cγη photoproduction ~940 MeV/c

p

p
d

π,η
~0 MeV/cnnlow-energy
ηn scattering

η~0 MeV/c

Fig.2. Expected diagram for the γd → pηn reaction at the incident photon energy of 0.94 GeV
and with the proton detection at 0◦ . The photon bombards the proton in the deuteron andproduces an η meson with a very low momentum. The ideal low-energy ηn scattering
takes place where the pn and ηp rescattering effects are suppressed due to their large
relative momenta.
and residual neutron is also very large (∼ 0.94 GeV/c). This large relative momentum gives little chance
to the interaction between the proton and residual neutron. The relative momentum between the protonand η meson is also very large (∼ 0.94 GeV/c), leaving little chance to the interaction between the protonand produced η meson. Thus the pn and ηp rescattering effects are thought to be suppressed.
The candidates of the exchange particle are π and η mesons in view of quantum numbers. The
mass of the exchange particle is close to the rest mass of the η meson make the η exchange enhanced
together with the condition that the η meson almost at rest is detected in the final state.
The sensitivity to ηn scattering length of the proposed reaction has been checked [13] using the
dynamical coupled-channels (DCC) model [6, 7]. The DCC model solves the coupled-channel LippmannSchwinger equation for meson-baryon scattering, where the coupled-channel unitarity, on- and off-shell
amplitudes are fully considered. The DCC model itself gives aηN = +0.75 + i0.26 fm, and rηN = −1.6 + i0.6 fm(2)

for the low-energy scattering parameters. The corresponding points are also presented in Fig. 1. Fourkinds of diagrams as shown in Fig. 4 are taken into account in the treatment of the γd → ηpn reaction.

Here, the γN → πN , γN → ηN , and πN → ηN amplitudes are given by the DCC model, and theamplitude for the pn final-state interaction (FSI) and deuteron wave function are provided by the CDBonn [14], Nijmegen I [15], and Reid93 [15] potentials. The differential cross section dσ/dMηn /dΩ arecalculated as a function of the ηn invariant mass (Mηn ). The contribution of each term shown in Fig. 4
can be obtained turning off the corresponding amplitude. The results of the calculation show
1. ηn rescattering effect is visible at the small ηn relative momentum (enhancement factor ∼ 1.2),
2. πn → ηn transition (π exchange) effect is small, and3. pn rescattering effect is also small.

The dσ/dMηn /dΩ values are calculated for different sets of Re[aηn ], and sensitivity of Re[aηn ] is

Recoil η Momentum (MeV/c)

15

300
250
200
150
100
50

magic momentum

0
700 800 900 1000 1100 1200 1300 1400 1500

Incident Photon Energy (MeV)

Fig.3. Recoil momentum of η mesons for the γp → ηp reaction for the free proton target. The
incident photon energy of 0.932 GeV can produce η mesons at rest.

ηn→ηn scattering

impulse

γ

η

γ
p

p
d

η

d

n
η

n
πn→ηn transition

pn rescattering

γ

γ

η
p

d
n

p
d

π
n
η

Fig.4. Four kinds of diagrams: impulse, ηn scattering, pn rescattering, and πn → ηn transition
terms, which are considered in the DCC model calculation for the γd → ηpn reaction [13].
The πn → ηn transition and pn rescattering terms are expected to be small.

16
checked. The dσ/dMηn /dΩ cross section with 5% error, binned in 1 MeV width of Mηn , can determine
the Re[aηn ] value at the precision of approximately ±0.1 fm. The model dependence of the deuteronwave function is found to be less than 0.5% near Mηn ∼ Mη + Mn . The details of the results can be3d σ/d Mηn dΩ p (µ b/MeV sr)found in Ref. [13], where the possibility of the effective-range (rηn ) extraction is also discussed.

0.6
full
imp+η+π
imp+η
imp

0.5
0.4
0.3
0.2
0.1
0

σX / σfull

1.8
1.6

ηn→ηn

1.4
1.2

πn→ηn

1

pn FSI

0.8
1.49

1.5
Mηn (GeV)

1.51

1.52

Fig.5. The differential cross section dσ/dMηn /dΩ as a function of the ηn invariant mass, whichis equivalent to the ηn relative momentum (upper panel). The solid curve (red) shows the
cross section from the full calculation, and the dotted curve (black) is the cross section using the impulse term only. The dashed curve (blue) shows the result from the impulse andη-exchange terms, and the dash-dotted curve (magenta) shows the impulse, η-exchange,and π-exchange terms, Ratios of the differential cross sections calculated to those fromthe full calculation (lower panel). This figure is taken from Ref. [13] [S.X. Nakamura etal., arXiv: 1704.07029 (nucl-th)].

§ 3. Experimental setup

The differential cross sections for the γd → pηn reaction will be measured at ELPH using the FOR-

EST electromagnetic calorimeter system [16, 17] together with an additional forward charged-particle
spectrometer [18]. Fig. 6 shows the experimental setup for the precise determination of aηn . The incident photon energy ranges from 0.82 to 1.26 GeV [11] for the circulating electron energy of 1.32 GeV
in the electron synchrotron [19]. The details of the FOREST detector including the liquid deuterium
target is described elsewhere [16]. The forward scattered proton is momentum-analyzed with a bending

17
magnet (transported from the low-energy ring of KEKB) behind FOREST. The trajectory of a charged
particle is measured with two planar drift chambers (DCs), and the time of flight is measured with aplastic scintillator (PS) hodoscope. Additional e/π and π/K separations are made using SF5 lead-glass
and aerogel Cherenkov counters, respectively.
PSs
SF5 for e/π
DCs

FOREST

proton emitted at 0 deg

γ γ

photon beamΝ

forward proton spectrometerFig.6. Experimental setup at ELPH for the precise determination of aηn . The momentum andtime of flight of the proton scattered at 0◦ are measured through a bending magnet. The
forward emitted proton is momentum-analyzed with a bending magnet behind FOREST.
The trajectory of a charged particle emitted at 0◦ is measured with two planar drift chambers, and the time of flight is measured with a plastic-scintillator hodoscope. Additionale/π separation is made using SF5 lead-glass Cherenkov counters.
The expected proton-missing-mass resolution, which corresponds to the ηN invariant-mass resolution, is approximately 5 MeV. The value of the mass resolution are given by the photon tagging resolution(0.5–2.5 MeV) [11], the time resolution for the PS hodoscopes (40 ps), and the flight length of approximately 4.5 m.
We plan to determine Re[aηn ] using the ratio of measured cross sections for γd → ηpn divided bythose for γp → ηp convoluted with the proton momentum distribution in the deuteron. This can reduce

the systematic uncertainty from the coverage of the forward spectrometer. The ratio also cancels theuncertainty of the elementary γp → ηp amplitudes [13]. Thus, we take both the data with the liquidhydrogen and deuterium targets. The first series of the experiments will start in the end of this October(2017) to determine Re[aηn ] with a precision of 0.2–0.3 fm. Our final goal is to provide the Re[aηn ](Re[rηn ]) value with a precision of 0.1 fm (0.5 fm) using more high-intensity photon beams.

§ 4. Commissioning

The measurement of the 3D magnetic flux of the bending magnet for the forward spectrometer BLC

is described in §4.1. The results from the test experiment for the additional detectors using positron

beams for testing detectors are reported: punch-through counters for SCISSORS III in §4.2, drift cham-bers (DCs) in §4.3, plastic-scintillator (PS) hodoscope in §4.4, and SF5 lead-glass counters in §4.5. In

18
addition, commissioning of the total system of the new FOREST experiment was made from May 22
to 30 in 2017 although the placement of the new detectors is temporary and we only take the liquidhydrogen data due to the accelerator trouble. This commissioning is described in §4.6.
4.1 Bending magnet for the forward spectrometer BLC
We placed a bending magnet, which was transported from KEK, behind FOREST to measure theforward emitted protons. This magnet was called local chromaticity correction bending magnet (Blc)used in the 3.5 GeV positron ring (LER) in KEKB. We call it BLC instead of Blc. The excitation test of
BLC with a dedicated power supply QC1LE was successfully finished on December 12 in 2016. We havedecided the standard coil current of BLC is 1400 A although BLC was used with a current of 1000 A at
maximum. The limit of the maximum current of 1400 A is determined by the primary 400-V current
source and cooling power by the water in the GeV-γ experimental hall.
The magnetic flux in the xy plane is obtained using a 2D static magnetic and electric field calculation code Poisson Superfish with an assumption of the z-axis translational symmetry. The calculated
magnetic flux at the center was 158.2 and 719.5 mT for the coil current of 300 and 1400 A, respectively.
We measured them and obtained values are 159.4 and 717.2 mT, which are consistent with the calculated
values within 0.5%. We also measured the 3D magnetic fluxes using a 3D hall probe, system, which wasborrowed from Strange Nuclear Physics laboratory, Department of Physics in Tohoku University, in thexy plane and along the z axis near the exit of BLC in December 2016 [20, 21]. Fig. 7 shows the x and ycomponents of the magnetic flux Bx and By , respectively, as a function of the x position. The calculated

10

0
-100
-200
-300
-400
-500
-600
-700
15

By

By [mT]

Bx

-300

-200

∆B

-100

0

100

200

300

400

x

Bmeas. - Bcalc. [mT]

80
60
40
20
0
-20
-40
-60
15
-80

Bmeas. - Bcalc. [mT]

Bx [mT]magnetic flux well reproduces the measured one.

10

5
0
-5

-200

-100

∆B

0

100

200

300

400

y

5
0

x

-5

-10

-10

-15
-300 -200 -100

y
-300

0

100

x [mm]

200

300

400

-15
-300 -200 -1000100

x [mm]

200

300

400

Fig.7. x component of the magnetic flux Bx as a function of the x position (left) and y componentof the magnetic flux By as a function of the x position (right). The upper panels shows
the measured Bx and By , and the lower shows the difference from the calculated one.
The different makers show different sets of the placement of the 3D linear stage for the
3D hall probe. The inset in the right-down panel shows the cross-sectional view of BLC
and definition of the x and y axes.

19
4.2 Punch-through counters for SCISSORS III
Charged particles emitted at forward angles can be separated using the correlation between energy
deposits in SPIDER and SCISSORS III. However, it is difficult to identify the charged particles which
penetrate the SCISSORS III calorimeter. To extend the separation power of them, we placed 56 plasticscintillator (PS) blocks with a size of 100×100×300 mm3 behind SCISSORS III. A 2-inch photomultipliertube (PMT) is connected through a light guide at a end for each block. To investigate the energy (light
output) response and time response as a function of the distance from the PMT window, we have tested
some of all the PSs using the positron beams for testing detectors. The PS blocks were originally used
for the TAGX experiments at the Institute of Nuclear Study (INS), University of Tokyo [24]. We have
two kinds of PS materials: both are transparent but one is colorless (NE102) and the other is yellow(produced by Kyowa Hakko Co., Ltd.).
To check the difference of the PS materials, several PS blocks made of each PS material were tested.
The momentum of the positron beam was 455 MeV/c, and it irradiated the PS block at five points fromthe edge to the PMT window. The trigger signal was generated in coincidence between the signals froma plastic scintillator with an area of 10 × 10 mm2 and thickness of 3 mm and plastic scintillator with anarea of 20 × 30 mm and thickness of 30 mm. The time resolution of this 30-mm thick PS is very high as
40–60 ps.

We fit the Moyal function (approximate Landau function) [22] to the measured energy distribution
to get the centroid µ and width σ. The energy resolution given by σ/µ is from 6% to 12%, and getting
worse from the PMT window to the edge. The individual differences of the energy resolutions are roughly
10%. The light output as a function of the distance from the PMT window is expressed byL(x) = L0 + L1 x2(3)

where x denotes the distance from the edge window. The L1 value is different by ±25% block by block,but the light output is well-reproduced in Eq. (3). We do not find any y-dependence in the light output,

and we do not observe any difference between two PS materials. We find a different light output depending on the PMT used (Hamamatsu H6410 or H1161, and whatever else). Fig. 8 shows the energy
resolutions and relative light outputs of the PS blocks in the punch-through counters as a function of the
distance from the edge window.
4.3 Drift chambers
Two drift chambers (DCs) are placed at downstream of the bending magnet BLC for measuring the
trajectory of a charged particle. The energy (momentum) of the particle will be basically determinedfrom the time of flight measurement since we do not have a tracking device in the entrance of BLC andsince we cannot achieve enough high momentum resolution. Thus the high position resolution is not
required for the momentum determination. However, it is important to determine the scattering angleof the emitted proton precisely from the x positions in the two DCs. The high position resolutions of
two DCs are required for this purpose. The diameters of the sense and field wires in DCs is 20 µm and100 µm, respectively. Each DC has 2 × 56 and 2 × 24 wires in the x and y planes, respectively. The drift

20

Fig.8. Energy resolution (left) and relative light outputs (right) of the PS blocks in the punchthrough counters as a function of the distance from the edge window. The energy resolution is given by σ/µ, where the centroid µ and width σ is obtained fitting the Moyalfunction [22] to each measured energy distribution. The different color lines show theresults on different individuals.

cell takes a square shape, and the half cell size is 10 mm.
The position resolutions of the DC planes were investigated using a 455 MeV/c positron beam fortesting detectors. The amplification gas used was a 50%-50% mixture of the argon and ethane since it
was difficult to operate the two DCs using a cheap P10 gas due to electric discharges. The trigger signal
was generated in coincidence between the signals from a plastic scintillator with an area of 10 × 10 mm2

and thickness of 3 mm in front of the two DCs and plastic scintillator with an area of 70 × 70 mm andthickness of 1 mm behind the two DCs.

At first, the optimum supplied voltage was searched for. The detecting efficiency of positrons as
a function of the supplied voltage (the plateau curve) was investigated, the efficiency reached approximately 100% above −2200 V. The drift velocity at −2200 V is found to be approximately 5.5 cm/µs,
which is consistent with Ref. [23]. The actual incident angle of the charged particles is not 0◦ , where theincident angle of 0◦ corresponds to the perpendicular incidence. Thus, the positron beams were injectedto the two DCs with incident angles of 0◦ and approximately 30◦ . Table 1 summarizes the widths of thex residual distributions, and intrinsic x position resolution with a perpendicular injection on the DCs
and supplied voltage to field wires of −2300 V. A two-DC set has four x planes and four y planes, andthe residual distribution for the x planes are discussed here. The x residual distributions were esti-

mated for the three- and four-plane fits. While the four-plane fit used four wires from all the x planes,
the three-plane fit used three wires from the three x planes excluding a wire in the x plane of interest.
The widths of the x residual distributions are denoted by σ3 and σ4 for the three- and four-plane fits,
respectively. The intrinsic position resolution σ was given by the geometric mean between σ3 and σ4√
namely σ = σ3 σ4 . The intrinsic x position resolution was approximately 0.3 mm for all the x planes,
and the y position resolution was also approximately 0.3mm.

21

Table 1. Widths of the x residual distributions, and intrinsic x position resolution. The positron
beam is injected on to the DCs perpendicularly, and supplied voltage to field wires is−2300 V. The σ denotes the intrinsic position resolution, which is given as the geometric√mean between σ3 and σ4 (σ = σ3 σ4 ), where σ3 and σ4 stand for the widths of theresidual distributions for the three- and four-plane fits, respectively. The residual isgiven as a difference between the measured and fitted x positions at the plane of interest.
The four-plane fit uses four wires from all the x planes, and the three-plane fit uses threewires from the three x planes excluding a wire in the x plane of interest.
DC1 X
DC1 X ′DC2 X
DC2 X ′

σ4 (µm)
205
225
223
202

σ3 (µm)
470
464
407
423

σ (µm)
310
323
301
292

4.4 Plastic-scintillator hodoscope
For the time-of-flight measurement of charge particles, we adopted the time-of-flight counters forneutrons (NTOF) developed for the E26 experiment in J-PARC (spokesperson: K. Ozawa). A each NTOF
counter consists of a plastic scintillator (PS) with a width of 100 mm, a thickness of 30 m, and a heightof 600 mm. The PS material is Saint Gobain BC-408. A 2-inch PMT, Hamamatsu H243, is connected ateach end of PS through a silicon cookie. The time resolution of the NTOF counter was once measured
at SPring-8/LEPS. The high resolution of approximately 60 ps was achieved. The NTOF counters havenot been used since the test experiment at LEPS, and the circuit used in LEPS for the NTOF counter isdifferent from ours. The circuit for the NTOF counters is planed to consist of QTC discriminators, Fuji
Diamond International GeVγ-1370, and multi-hit TDC modules, CEAN V1290A.
To investigate the time resolution of the NTOF counters, we have tested some of them using thepositron beams for the testing detectors at ELPH. We place each TOF counter rotating so that thetwo PMTs were in the left and right sides. The trigger signal was generated in coincidence between
the signals from a plastic scintillator with an area of 10 × 10 mm2 and thickness of 3 mm and plastic

scintillator with an area of 20 × 30 mm and thickness of 30 mm. The time resolution of this 30-mm thick
PS is very high as 40–60 ps.

Positron beams were injected not only the center but also ±5-, ±10-cm shifted in the horizontallyfrom the center. Fig. 9 shows the typical time difference distribution between the top and bottom PMTs.
The width obtained was 3.1 channels fitting a Gaussian function to the distribution. Since the channelto-time coefficient is 27.5 ps/channel, the time resolution of the difference was found to be 85 ps. We
tested two NTOF counter with various conditions, the widths of the time differences are approximately
90 ps. The actual time is determined averaging the times from the top and bottom PMTs, and theprecision of the time measurement is approximately 45 ps. Suppose the intrinsic time resolutions forthe top and bottom PMT are σ1 and σ2 , the time resolution of the difference σ12 is determined from2
= σ12 + σ22 . Thus the time resolution of the average of the top and bottom PMTs σ is given by
σ12

σ 2 = σ12 /4 + σ22 /4 namely σ = σ12 /2. The positron beams were injected onto an NTOF counter not only
perpendicularly but also with an incident angles of approximately ±20◦ .

22

Fig.9. Typical time difference distribution between the top and bottom PMTs. The width obtained is 3.1 channels fitting a Gaussian function to the distribution. Since the channelto-time coefficient is 27.5 ps/channel, the time resolution of the difference is found to be
85 ps.

4.5 SF5 lead-glass counters
The SF5 lead-glass counters are placed at most downstream of the detectors behind the bending
magnet BLC. To save the space between the detectors and the west wall in the GeV-γ experimental hall,
they are placed so that the PMT is at the top (usually PMT is placed at the rear side from the surface
that charged particles inject). This placement is the similar to that adopted in the E325 experimentin the proton synchrotron at KEK. We have tested ten SF5 counters in total and investigated theirenergy resolutions using the 100–800-MeV/c positron beams for testing detectors at ELPH. The energy
resolution was determined by σ/µ where µ denotes the centroid and σ denotes the width. The µ and σ
were obtained fitting a Gaussian function to the measured energy distributions. The energy resolutions
were found to be approximately 13%–14%, and constant almost independently of the incident energy. In
general, the (relative) energy resolution becomes higher as the incident positron momentum increases.
Injecting positron beams on the side surface of the SF5 counter, the effect of the longitudinal leakageof the electromagnetic shower is large. And the fraction of the longitudinal leakage becomes larger as
the incident energy increases. In addition, the number of photoelectrons becomes larger and the staticalfluctuation becomes smaller as the incident energy increases. These two contributions are expected tobe canceled, and the energy resolution is approximately constant independently of the incident energy.
Next, we discuss the separation power of the positrons to charged hadrons. Fig. 10 shows themean and width of the measured energy distribution of the SF5 lead-glass counter as a function of theincident positron energy. It should be noted that the positron beams are injected from the side surfaceof the counter. When a high-energy positron enters the SF5 counter, the electromagnetic shower takes
place. No shower takes place when a charged hadron enter the counter. Thus the energy response to a

23charged hadron is expected to be similar to cosmic rays µ± . Simply thinking, the positron and a charged
hadron are expected to be separated using the SF5 counter at momenta higher than 300 MeV/c as show
in Fig. 10. The measured energy becomes high once a charged hadron makes a nuclear reaction in theSF5 counter. Thus the usage of particle identification using the SF5 counter is useful but is not perfect.

positrons
can be erjected

EM shower

MIP penetration w/o EM shower
region ofinterest
Fig.10. Mean µ and width σ of the measured energy distribution of the SF5 lead-glass counteras a function of the incident positron energy. The positron beams are injected fromthe side surface of the counter. The black data points show the µ value with an error
bar corresponding to the σ value. The red data point represent the result from themeasured energy distribution using cosmic rays. The incident of energy of the cosmicray measurement is determined in view of an equivalent energy deposit in the SF5
counter. The positron and charged hadron are expected to be separated using the SF5
counter at momenta higher than 300 MeV/c.

4.6 Commissioning
Commissioning of the new FOREST experiment was made from May 22 to May 31 in 2017. Originally our beam time had been assigned from May 15, but the beam time from May 15 to May 21 wascanceled owing to the accelerator trouble happened on May 15 (error in the high voltage supplier of theelectron synchrotron). The operation of the accelerators was recovered on May 22. Since the construction of the detector frame for the forward detector was not finished, the placement of the detectors were
temporary. Fig. 11 shows the experimental setup of the detectors for the forward spectrometer. In thetemporary setup, we placed two DCs, nine NTOF counters, and six SF5 lead-glass counters in order fromthe upstream.
The readout of sense wires in the two DCs was made using the 32-channel RAINER board. We used

24

]

[

Top view\

Fig.11. Experimental setup of the detectors for the forward spectrometer. The left panel shows
the schematic top view of the detectors. The right panels shows a photo taken from thesouth-east. Two DCs, nine NTOF counters, and six SF5 lead-glass counters are placedin order from the upstream.
six boards out of ten due to the troubles, and readout signals from 64 x wires and 24 y wires from each
DC. Although we took signals from all the y wires, we took signals from wires in a 64-cm width in the
BLC side. The two DCs are planed to be placed at the angle of 15.7◦ with respect to the z axis in the new
FOREST experiment. However, the DC wire planes are placed perpendicular to the z (photon beam)axis in this commissioning.
The power supply for BLC, QC1LE, halted many times, indicating the ground fault error, after
we operated the two-stage Gifford-McMahon (GM) refrigerator, Sumitomo Heavy Industries RKD-415D.
The error was thought to happen because the resistance of cooling water is not enough high together
with the noise from the refrigerator. We plan to insert ion-exchange resins in the cooling systems for the
power supplier of the magnets and magnets themselves. To suppress the halt of the BLC excitation, we
decrease the coil current from 1400 A to 1250 A.
First of all, we checked whether the two DCs worked well or not using the data from special runs.
In these special runs, the trigger condition of the data acquisition was logic OR signal of all the tagging
signals, and thick converter was placed in front of BLC to produce the positrons with the speed of lightfrom a faint photon beam. Almost all the charged particles came to the two DCs were positrons fromtagged photons. We estimated the correlation of the TDC values between the odd- and even-number
wires to confirm that we correctly measured the response times from the wires. Sense wires are placed
alternately in the X (Y ) and X ′ (Y ′ ) planes. When charged particles are incident on a drift chamber
perpendicularly, they penetrate the interval between adjacent X and X ′ wires. Thus the sum of the
TDC values for the adjacent X (Y ) and X ′ (Y ′ ) wires must be constant. Fig. 12 shows the correlationof the TDC values between the adjacent odd (2i − 1)- and even (2i)-number wires. As shown in Fig. 12,

Event concentrations are observed at the constant sum loci in the Y -Y ′ planes for DC1 and DC2. On
the other hand, Charged particles are incident on a DC at the incident angles larger than 10◦ in thezx plane. And this incident angle becomes larger as the distance from BLC becomes longer. Charged

25particles are more likely to pass through the same side from the sense wires of the X and X ′ planes in
the far side (south) . The loci corresponding to the constant difference is longer for the far side. The locicorresponding to the constant sum is longer for the near side (north).

X (south)

Y

DC2

DC1

TDC value (even wire)

X (north)

TDC value (odd wire)
Fig.12. Correlations of the TDC values between the adjacent odd (2i − 1)- and even (2i)-number
wires. The upper and lower panels show the correlations for DC1 (upstream) and DC2(downstream), respectively. The left, central, and right panels show the the correlations
for the X-X ′ wires in the near side (north), in the far side (south), and Y -Y ′ wires,
respectively.
Next, we checked the correlation of the wire numbers in the X-X ′ planes between DC1 and DC2 toknow the incident angle of charged particles. Fig. 13 shows the correlation of the wire numbers in the
X-X ′ planes between DC1 and DC2. The 8th wire in the X-X ′ planes of DC1, which was removed to
avoid the ground fail, was missing. Event concentration corresponds to the correlation for the positrons
between the wire number in the X-X ′ planes of DC1 is higher than 20 and that of DC2 is larger than
25. Since the positrons are mainly produced from the photon beam, and the maximum energy of thepositron corresponds to the circulating energy of the primary electron in the synchrotron approximately
1.3 GeV. Thus events of the positron incidence exist for the wire numbers in the X-X ′ planes of DC
larger than 20. Event concentration in the lower part corresponds to the correlation for the events
that charged particles or X rays pass through the two DCs coming from the beam dump because wire
number is smaller in DC2 suggesting dx/dz < 0. Event concentration in the left side correspond tothe correlation for the events that the high-energy positive hadrons are incident on the two DC2, or forthe events that charged particles come directly without passing through BLC. If charged particles arecorrectly momentum-analyzed in BLC, events for the wire numbers of DC1 smaller than 15 correspondto charged particles with energies higher than 1.3 GeV. If charged particles do not pass through BLC,

26
they can also come to the region corresponding to the wire number of DC1 smaller than 15.
correlation
for the positrons

a wire is missingin X-X’ planes of DC1
60

22500
20000

50
17500
15000

DC2X wire

40

12500
30
10000
7500

20

correlation
for the high-energy
positive hadrons,
or direct incidence 10

5000
2500

5

10

15

20

25

30 35 40
DC1X wire

45

50

55

60

0

correlation
for the passing throughfrom the beam dump

Fig.13. Correlation of the wire numbers in the X-X ′ planes between DC1 and DC2. The 8th
wire in the X-X ′ planes of DC1 is missing. Event concentration corresponds to thecorrelation for the positrons between the wire number in the X-X ′ planes of DC1 ishigher than 20 and that of DC2 is larger than 25. Event concentration in the lower
part corresponds to the correlation for the events that charged particles or X rays passthrough the two DCs coming from the beam dump. Event concentration in the left sidecorrespond to the correlation for the events that the high-energy positive hadrons are
incident on the two DC2, or for the events that charged particles come directly without
passing through BLC.
Since the coil current for BLC was as low as approximately 1250 A in the commissioning period dueto the power supplier (QC1LE) trouble , we cannot get enough bending power. Protons with a momentum
around 940 MeV/c, which is of most interest to determine low-energy ηn scattering parameters fromthe γd → pηn reaction, comes onto the second NTOF counter from the BLC side. We have estimatedthe time difference distributions between a NTOF counter and tagging signals to check whether the
positive pions and protons are well separated or not. Coincidence between the FOREST detector andtagging signal is required to remove the accidental background contributions. A sideband-subtraction
method was applied to get the coincidence of them, where the prompt time difference (the FOREST time
is subtracted by the response time of hte tagging signal) region was defined from −8 to +2 ns and thebackground from −28 to −8 and from +2 to +22 ns. Fig. 14 shows the time difference distributions

between the NTOF and tagging signals for eight NTOF counters. Here, the coincidence between the
FOREST detector and tagging signals was confirmed. The connection of the top PMT to the first NTOF

27
300
TOF2
300

1022 MeV/c

TOF3
200

200
100

100

100
0
400
Counts / 0.5 ns

TOF4670 MeV/c

817 MeV/c

200

300

300

0
TOF5

562MeV/c

0
TOF6

300

480MeV/c

TOF7
300

200

200

100

100

100

0
400

0

300

365 MeV/c 400

200

TOF8

TOF9

323 MeV/c

415 MeV/c

0-650 -640 -630 -620 -610 -600
ttof - ttag (ns)

300
200
200
100

100

0
0
-650 -640 -630 -620 -610 -600 -650 -640 -630 -620 -610 -600

Fig.14. Time difference distributions between the NTOF and tagging signals for eight NTOF
counters. The coincidence between the FOREST detector and tagging signals is required. The block, magenta, green, and red vertical lines represent the time difference
for the positrons, positive pions, positive kaons, and protons with an energy of central
momentum coming to each NTOF counter.
was broken during the experiment, and light output was very small. Thus, we omit the first NTOF
(TOF1) data.
We compared the measured time difference to the calculated time difference for the positive pions,
positive kaons, and protons with an energy of central momentum coming to each NTOF counter. To
make the calibration of the time difference, the position corresponding to the positron peak was obtainedusing the special runs, in which the trigger condition of the data acquisition was logic OR signal of all
the tagging signals, and thick converter was placed in front of BLC to produce the positrons with the
speed of light from the photon beam. Both the positive pion and proton peaks were clearly observed
from the second (TOF2) to fifth (TOF5) NTOF counters, corresponding to the momentum above 562
MeV/c. It should be noted that still we have a large amount of the uniform background contribution
from accidental coincidence.

28
Since we successfully readout the signals from DCs, the time difference distribution can be also
estimated wire by wire. Fig. 15 shows the correlation between the wire number in the X-X ′ planes of
DC1 and time difference between the NTOF and tagging signals. The loci corresponding to the positive
pions and protons were clearly observed. The scattering angle of charged particles in the horizontal
plane which can be correctly momentum-analyzed ranged from 0◦ to 1◦ . Different scattering angles makedifferent flight lengths, and make the time difference distributions broader. After the T0 calibration andxt curve determination for the DC wires are finished, the time difference distributions will be estimatedmore accurately.
60
40

35

30
50
DC1X wire number

X position (~ momentum)

55

25
45

20

15
40
10
35

30
-650

5

0
-645

-640

-635
ttof-ttag

-630

-625

-620

time of flight

Fig.15. Correlation between the wire number in the X-X ′ planes of DC1 and time difference
between the NTOF and tagging signals. The loci correspond to the positive pions (left)
and protons (right) are clearly observed.

§ 5. Summary

An experiment is planed at ELPH using the FOREST detector to determine the ηn scattering

length aηn using the γd → pηn reaction. Proton detection at 0◦ using 0.94 GeV photon beam givethe recoilless condition of η mesons. The ηn final-state interaction can be studied thanks to the small
relative momentum between ηn. Commissioning of the new detectors at downstream of the forward
spectrometer has been finished. The first series of the experiments will start in the end of this October(2017) to determine Re[aηn ] with a precision of 0.2–0.3 fm. We will provide an accurate Re[aηn ] value(∼ 0.1 fm) in the near future.

29

Acknowledgments
The authors give thanks to the ELPH accelerator staff for their great efforts in the stable operationof the electron synchrotron. They deeply acknowledge S.X. Nakamura and H. Kamano for giving us
the predictions for the ηn rescattering effect in the proposed γd → pηn experiment. This work was

supported in part by Grants-in-Aid for Scientific Research (A) (24244022), for Scientific Research (C)(26400287), and for Scientific Research (A) (16H02188).

References[1]

Q. Haider and L.C. Liu: Int. J. Mod. Phys. E 24, 1530009 (2015);
and references therein.

[2]

A.M. Green and S. Wycech: Phys. Rev. C 71, 014001 (2005);
Erratum Phys. Rev. C 72, 029902 (2005).

[3]

R.A. Arndt et al.: Phys. Rev. C 72, 045202 (2005).

[4]

C. Patrignani et al. (Particle Data Group): Chin. Phys. C 40, 100001 (2016).

[5]

S.D. Bass and A.W. Thomas: Phys. Lett. B 634, 368 (2006);
S.D. Bass and A.W. Thomas: Acta Phys. Polon. B 45, 627 (2014).

[6]

A. Matsuyama, T. Sato, T.-S.H. Lee: Phys. Rep. 439, 193 (2007).

[7]

H. Kamano et al.: Phys. Rev. C 88, 035209 (2013).

[8]

A. Sibirtsev et al.: Phys. Rev. C 65, 044007 (2002).

[9]

A. Fix and H. Arenhövel: Eur. Phys. J. A 19, 275 (2004).

[10] T. Ishikawa et al.: ELPH-2803 letter of intent (2014);
T. Ishikawa et al.: ELPH-2844 experiment (2016).
[11] T. Ishikawa et al.: Nucl. Instrum. and Meth. A 622, 1 (2010).
[12] T. Ishikawa et al.: Nucl. Instrum. and Meth. A 811, 124 (2016).
[13] S.X. Nakamura, H. Kamano, and T. Ishikawa: arXiv: 1704.07029 (nucl-th).
[14] R. Machleidt: Phys. Rev. C 63, 024001 (2001).
[15] V.G.J. Stoks, R.A.M. Klomp, C.P.F. Terheggen, and J.J. de Swart: Phys. Rev. C 49, 2950 (1994).
[16] T. Ishikawa et al.: Nucl. Instrum. and Meth. A 832, 108 (2016).
[17] T. Ishikawa et al.: Phys. Lett. B 772, 398 (2017);
T. Ishikawa et al.: PoS (INPC2016) 267;
T. Ishikawa et al.: PoS (Hadron2013) 095.
[18] T. Ishikawa et al.: JPS Conference Proceedings 13, 020031 (2017);
T. Ishikawa et al.: JPS Conference Proceedings 10, 031001 (2016).
[19] F. Hinode, et al.: Journal of Physics: Conference Series 425, 072011 (2013).
[20] T. Ishikawa, Internal GeV-γ Analysis Note HD No. 413N (2016).
[21] Y. Inoue, Internal GeV-γ Analysis Note HD No. 415N (2017).

30[22] J.E. Moyal, Phil. Mag. 46 (1955) 263; M.D. Marucho, C.A. Garcia Canal, H. Fanchiotti, Int. J. Mod.
Phys. C 17 (2006) 1461.
[23] A. Peisert, F. Sauli, Drift and Diffusion of Electrons in Gases: A Compilation, CERN-84-08 (1984).
[24] K. Maeda, private communication.

ELPH Annual Report, Tohoku University (2016)31(ELPH Experiment : #2823)

Evaluation of Time Projection Chamber for H-dibaryon
search experiment and test of Multi-gap Resistive Plate
Chamber for J-PARC Heavy-Ion project
H. Sugimura1∗ , T. Chujo2 , H. Ekawa1 , S. Hasegawa1 , Y. Ichikawa1 ,S. Kimbara1 , H. Sako1 , S. Sato1 , K. Tanida1 , J.K. Ahn3 , S.H. Kim3 ,W.S. Jung3 , W.J. Choi3 , J.Y. Lee4 , R. Aoyama2 , T. Ichisawa2 , H. Kato2 ,T. Nonaka2 , K. Sato2 , T. Sugiura2 , and M. Inaba5
12Japan Atmic Energy Agency (JAEA), Tokai, Ibaraki, 319-1195, Japan

Faculty of Pure and Applied Sciences, Division of Physics, University of Tsukuba, Tsukuba,
Ibaraki, 305-8571, Japan
3

4

Department of Physics, Korea University, Seoul 02841, Republic of Korea

Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of
Korea

5

Faculty of Industrial Technology, Tsukuba University of Technology, Tsukuba, 305-8520, JapanA Time Projection Chamber (TPC) has been developed for an H-dibaryon experiment at J-PARC.
The TPC consists of readout pad, three-layer GEM, gating-grid and field cage. To evaluate basic performance, we have conducted beam test with positron beam at Research Center for Electron Photon Science(ELPH). In event display, the positron track was clearly seen, and position resolution was measured to
be 400 µm in the pad direction and 600 µm in the drift direction, respectively. In parallel, Multi-gap Resistive Plate Chamber (MRPC) was tested for time resolution study for the J-PARC Heavy-Ion Project.

§ 1. Introduction
1.1 Time Projection Chamber
We have proposed the H-dibaryon search experiment via (K − , K + ) reaction at Hadron Experimental Facility, J-PARC. The proposed experiment will be measured invariant mass spectrum of ΛΛ or Λpπfrom H decay, with a mass resolution of 1 MeV/c2 . To measure this decay mode, we have developed the
TPC (Fig.1). The TPC has the octagonal drift volume defined by the field cage, the cathode plane at
the top and the amplification region at the bottom. The whole volume is filled with a gas mixture of
Ar-CH4 (P-10). The target is located inside the drift volume. For amplification, we adopted tripple GEMs
with the configuration of 50 µm for top two layer and 100 µm for bottom layer to achieve gain of the 104
level. The most characteristic specification of our TPC is to operate not only decay particle but also highrate kaon beam up to 106 cps. In high rate operation, space charge effect in the drift volume can notneglect. To reduce this, we adopted to locate gating grid just above the top of GEM layer. The purpose∗

Present address: High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801,
Japan

32
of the ELPH experiment is to evaluate position resolution and position shift due to space charge effectwith and without gating grid.

Fig.1.

(left) The picture of developed TPC. (right) Gating wire, GEM, readout pad and conversion
connector from the top picture.

1.2 Multi-gap Resistive Plate Chamber
A Multi-gap Resistive Plate Chamber (MRPC) is one of the most commonly used apparatus asa time-of-flight detector for charged particle identification. MRPC is the basically a gaseous detector
operated at the avalanche mode, and applying a high voltage on the electrode, which is usually about
14 kV. In between the electrodes, we produced many gas gaps by stacking many high resistive materials,
such as float glasses, with a spacing of few µm gas gap. When a charged particle passes through, theelectron avalanche develops and it induces charge on the readout pad. This is the signal with a goodtiming characteristics, and we can build TOF detector easily less than 100 ps of timing resolution withhigh detection efficiency.
We have been working on the prototype of MRPCs for many years, to optimize the various parameters of this detector, seeking for the timing resolution below 30 ps. At this beam test experiment at
ELPH, we have tested basically three types of MRPC detectors as follows.
• Small area MRPC (4 stacks)• Large area MRPC (4 stacks)• Small area MRPC with narrow pad width (1 stack)We show the results at this beam test for each type of MRPC in Sec3.2.

§ 2. Experimental Setup
The experimental setup is shown in Fig.2. There are several counters to evaluate the TPC performance. A large plastic scintillation counter (T1) whose size is 50H mm × 50V mm, is located at themost upstream. A small plastic scintillation counter (F1) whose size is 1 cm × 1 cm, is located at justdownstream of the T1. Two silicon-strip detectors (SSD) with an 80 µm strip pitch and a sensitive area

33
of 31H × 30.8V mm2 were located in front of and behind the TPC, respectively. The TPC was locatedbetween two SSDs. The positron beams are measured by the SSD and the TPC. The SSDs play a role ofreference of the track position to evaluate beam shift due to space charge effect inside of the TPC. T2 andF2 are same counter as T1 and F1, respectively and are located at the downstream of the SSD2. A plastic
scintillation counter (VETO) has a small hole at beam through position to detect scattered positron andto reject from trigger, and is located at behind the F2. MRPCs were located at downstream of the TPC
measurement counters.
HypTPC
beam

MRPC
T1

F2
F1

T2
SSD2

SSD1

Fig.2.

ELPH setup

VETO

34

§ 3. Analysis
3.1 TPC analysis
3.1.1 No Gating-Grid operation
In this ELPH expetiment, we tested basic performance of the TPC. Figure 3 left shows event displayof positron track. Pad color indicates amount of charge deposit of each pads. The track was clearly seenat central position. A concerning point is that the track was slightly bent at the edge of the TPC. The
reason has not been recognized yet.
Figure 3 shows typical wave form. Dynamic range was set to 120 fC and the shaping time was
212 ns with VGEM of 315 V. S/N ratio was more than 100 that is because we could identify the clear
signal.

Fig.3.

(left) Event display of the positron track. (right) Typical wave form get from readout pad.

Figure 4 shows the pad efficiency of each layer. The horizontal axis shows layer number. The orderof layer number is defined from central target position, and total layer is 32. The “ncl” indicates numberof cluster. The signal was clustered in each layer. The pad efficiency was estimated more than 90% at
the ncl ≥ 2, and more than 99% at the ncl ≥ 1. However, there were some low efficiency layers. Theselayers could not be measured because of the GEM broken. In this test measurement, we found that the
GEM was often broken at more than 320 V. To increase 320 V, we should modify GEM structure (support
frame etc.) and take long time aging.
Figure 5 shows typical residual distributions in the direction of pad and drift, respectively. We
tested with no magnetic field (B = 0) and low electric field (E = 130V /cm), which is relatively lower
than operation voltage (E = 180V /cm) [1]. In the pad direction analysis, we applied cluster size morethan 3 and calculated position with weighted mean method. The position resolution was estimated to400 ∼ 500 µm. In the drift direction analysis, we calculated from maximum time bin obtained from thewave form, and applied mean value from the Gauss fit. The position resolution was estimated to 500 ∼600 µm.
3.1.2 Gating Grid operation
Figure 6 shows typical wave form of gating grid operation. We applied gating voltage at the range
from ±25 V to ±50 V. The leftmost oscillation from 20 to 150 time bin and the rightmost peak from 420

35

Fig.4.

Fig.5.

Pad efficiency of each layer.

Residual distributions in the direction of pad and drift, respectively

36time bin show noise induced by the leading and trailing edges of the gate pulse. The middle peak is thesignal from positron track at the height of 45 cm from gating grid. In the no gating grid operation, S/Nratio was more than 100. However, we can not neglect gating pulse noise. If the tracks pass throughnear the gating grid, signal is overlapped with gating pulse noise. Figure 7 shows pad inefficiency at
the height of 45 cm when the gaint grid is CLOSE. In the closed mode, signal can not be reached at
the amplification area (GEM). If gating grid CLOSE level is low, some charge is leaked and amplifier at
GEM. Signal was not detected around the Vgate = 50.
In this test experiment, we didn’t take data at low height operation with gating grid. Detailed
gating grid study will be measured near future.

Inefficiency [%]

1400
1200
1000

100

800

60

600

40

400

20

200
0
0

Fig.6.

80

100

200

300

0
0

400
500
Time [40 ns/bin]

Typical wave form of gating grid operation

Fig.7.

10

20

30

40

50
Vgate [V]Inefficiecy of the Gate CLOSE operation

3.2 MRPC analysis
3.2.1 Small area MRPCWe developed 4-stucked MRPC, which is called “Small area MRPC”. Its effective area is 100 mm
wide and 136 mm long, and total hight is about 30 mm. The signal can be read out from both sides ofread out pad. In this type, we measured timing resolution and efficiency as a function of applied voltage
and position. Figure 8 shows a sample of signal shape taken by the DRS4 evaluation board [2]. Threeparameters were extracted by fitting a signal, i.e. amplitude of signal A, charge Q (integrated around apeak), and a time when it reaches at A/2, t0 .
The correlation between amplitude and charge is shown in Figure 9. A linear distribution is seenat the middle panel, and some points are placed above the line. These can be considered as streamers,
which usually have two-peaked signals as shown in the top-left, and a larger decay time as shown in thebottom-left panel.
Figure 10 shows the voltage dependence of efficiency. The efficiency is defined as the ratio of thenumber of events whose amplitude of MRPC signals are > 10 mV to the number of triggered events byscintillation counters. Filled circles are for the efficiency including streamers, and open circles are thefraction of the streamers over the total number of events.
The color (red or blue) corresponds to the different position of beam spot as shown in the figure.

37
Figure 10 shows that the efficiency gets better to be > 98% more than 12.5 kV.
Figure 11 shows the timing resolutions as a function of the applied voltages. The beam was irradiated at the center of the counter. Streamer events are excluded from this analysis because rising signal
might be deformed by the pulses come after, and exact t0 parameter cannot be measured correctly. weachieved the timing resolution of 67.4 ± 2.8 ps at 12.0 kV and achieved efficiency up to 98% at the sametime. We concluded that the best voltage setting for this type of MRPC is 12.0 kV from this data.

Fig.8.

Signal taken by DRS4 evaluation board and the method of data extraction

Fig.9.

Scatter plot of amplitude and charge. Plots are divided into 3 groups.

38

Fig.10.

Efficiency and the ratio of streamer, applied voltage and beam spot dependence

3.2.2 Large area MRPC
Figure 12 (left) shows 30 × 20 cm2 large prototype of MRPC (4 stuck), and we evaluated it withbeams at ELPH. We took data in 4 different high voltage setting at each position (7 points), as shown in
Figure 12 (right).
We evaluated applied voltage and position dependence of timing resolution (Fig.13 left). The best
timing resolution was 79.8 ± 1.8 ps at position No.5 when the applied voltage was 15.0 kV. This figure
shows that the time resolution went the better with inclease applied voltage. However, it looks different
structure at position No.2, and it can be considered that positron beam hit outside of the pad of MRPC.
We originally expected the best value of timing resolution would be at the center because it wasconsidered that the signal is read out of both side of pad at the same time. However it turned out to be
the opposite result. The applied voltage and position dependence of the efficiency are shown in Fig.13
right. The efficiency got the better with increase applied voltage. On the other hand, if the beam position
got closer to the detector center, the efficiency got worse. These effect can be considered that the large
reflection of the signal, because on the edge of the pad, the true pulse and reflected signal are almost
close to each other, then the amplitude is bigger. But the beam hit in the center, true pulse and reflectedsignal are located next to each other, smaller amplitude and broader pulse would be formed by true
pulse and reflected pulses, it causes worse timing resolution. Those results indicate the importance of
the impedance matching among detector, cables, and pre-amplifier.

39

Fig.11.

Fig.12.

Timing resolution. The beam spot is the center.

left:prototype of large MRPC , right:positron beam incident position

3.2.3 Small area MRPC with narrow pad width
The purpose of this study is to evaluate the pad width effect to the timing resolution and efficiency.
In here, we used the single stuck MRPC. In this study, we collaborated with SONY Global Manufacture& Operation. They performed the electromagnetic field simulation. Based on the simulation results, it
is possible to improve and optimize the wave shape quality of MRPC by changing the pad shape. We
made the same type of MRPC as the simulation and performance beam test for those at ELPH.
In this experiment, we made 2 types of MRPCs. One is the reference counter whose width of thereading pad is 2.4 cm. This type is same shape of “Small area MRPC”, as we discussed before. We call it
as “type A”, and the other is “type B” which has narrower width of reading pad to 1.2 cm than the typeA.
We measured the efficiency using e.q.1. ”NM RP C.th ” is number of events in which the amplitude of40
Timing Resolution(MRPC1&MRPC2)

220
200
180
160

90
80
70

140

60
50

120

40

100

30

80
60
−15

Fig.13.

100

efficiency [%]timing resolution[ps]4-stack 165µm
13.0 kV
14.0 kV
14.5 kV
15.0 kV

240

−10

−5

0

5

10

position[cm]20

13.0kV10

14.5kV0−15

14.0kV
15.0kV

−10

−5

0

5

10

15

position [cm](left) position and applied voltage dependence of timing resolution, (right) position dependence of efficiency

MRPC exceeding certain threshold. In this analysis, the threshold value is set to 10 mV. ”Nallevents ” isthe number of all trigger events. Both A and B types of MRPCs are obtained over 95% efficiency.
ef f iciency[%] =NM RP C.th
× 100
Nallevent(1)

We measured the rise times because it is one of the important elements. The quality of the waveform
determines the timing resolution. We defined raise time as the time taken amplitude from 10% to 90%.
Fig.14 shows a comparison of rise time for type A and type B. It shows the raise time of type B isfaster than type A. This indicates that type B have a good wave shape compared to that for type A. So
that it is expected that the timing resolution is better for type B. We measured the timing resolution:
Type A is 85.4 ± 2.4 ps and type B is 78.9 ± 1.8 ps (Fig.15). We did not observed a clear difference on
timing resolution by considering statistical uncertainties. The band width of pre-amplifier would not
be optimized yet for the higher frequency (GHz). It is thought that the effect of timing resolution withdifferent pad could be seen by using a high frequency pre-amplifier to catch a wider bandwidth.

Fig.14.

Applied voltage dependence ofraise time. Comparison of type A
and type B.

Fig.15.

Applied voltage dependence oftiming resolution. Comparison oftype A and type B.

41

Acknowledgment
We would like to acknowledge the ELPH accelerator staffs to provide the stable beam. This work
was supported in part by Grants-in-aid for Research on Innovative Areas 2404, No. 24105002, KAKENHI
Grant-in-aid No. JP15K13475, and Toray Science and Technology Grant.

References[1]

J.K. Ahn et al.: Technical Design Report of J-PARC E42 experiment.

[2]

DRS4 Manual, https://www.psi.ch/drs/DocumantationEN/manual rev30.pdf

42

ELPH Annual Report, Tohoku University (2016)(ELPH Experiment : #2825:#2855)

大強度電子線形加速器を用いた 22Na、24Na の生成
石久保宏平１,上田惟行１,小松巧１,塚田暁１,二宮慎吾１,吉田千尋１
１

東北大学電子光理学研究センター（982-0826 仙台市太白区三神峯 1-2-1）

Production of 22Na and 24Na with a high-intensity
electron beam
K. Ishikubo1, T. Ueda1, T. Komatsu1, K. Tsukada1 ,S. Ninomiya1 , C. Yoshida1
1Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826

By irradiating the 50 MeV electron beam on 27Al target, 24Na and 22Na were generated via thephotonuclear reaction. The amounts and spacial distributions of generated RIs were measured by NaI
scintillation counters, Germanium detector, and the imaging plate.
The experimental results are compared with Geant4 simulation.

§１.はじめに本研究では電子光理学研究センターの所有する大強度線形加速器を用いて 27Al に 50MeV 電子ビームを照射し、22Na および 24Na を生成した。NaI シンチレータと Ge 半導体検出器を用いて RI の生成量と半減期を測定し Ge 半導体検出器とイメージングプレートを用いて RI 生成分布をそれぞれ測定した。
今回測定する放射線は、22Na では 1.27MeV 及び β 崩壊からの陽電子が対消滅して生じる 0.511MeV の
γ 線、24Na では 2.75MeV と 1.37MeV の γ 線である。測定から得た結果との比較を Geant4 [1] を用いたシミュレーションで行った。
本研究では、２回のビーム照射を行った。１回目のビーム照射では RI の生成量を測定することを目的とした。２回目のビーム照射では Al ブロック内での放射化分布の広がりを調べることを目的とした。
§２．生成量測定実験
今セクションでは１回目のビーム照射について説明する。
2.1．ビーム照射のセットアップ
電子ビーム照射による RI の生成量を調べる。ターゲットの厚さでの生成量の違いの検証のためにターゲットをそれぞれ 1cm 片の Al 板で厚さ 1mm を１枚、2mm を 2 枚とした。
セットアップは第１図になる。
今回のビーム照射では 50MeV 電子ビームをアベレージカレント 100µA で 5 時間照射した。
2.2．NaI シンチレータでの測定
ビーム照射直後から一週間の 24Na のレートの高いうちはコリメータを用いて 24Na を測定した。レートの下がった後は二つのシンチレータを用いてコインシデンス測定にて２２Na を測定した。それぞれのセットアップを第２図に示し、得られたヒストグラムを第３図にまとめる。

43

第１図 生成量測定のビームセットアップ

第２図 NaI シンチレータ測定のセットアップ（左 24Na 測定、右 22Na 測定）

第３図 得られたヒストグラム（左 24Na、右コインシデンス測定による 22Na）
2.3．Ge 半導体検出器での測定照射した 3 枚の Al 試料について、電子光理学研究センター第三実験室にある Ge 半導体検出器を用いて測定を行った。測定時間は約 10 分。測定のセットアップは第４図にまとめた。

44

試料の中心が Ge 結晶の中心とほぼ一致するように垂直方向に 5cm 離して置いた。
測定で得られたヒストグラムを第５図に示す。

第４図 測定のセットアップ（左概略図、右実際のセットアップ）

第 5 図 得られたヒストグラム
2.4．シミュレーション
RI の生成量は以下の式で見積もることができる。
Y = σ · 𝐼𝐼𝑒𝑒 ∙ 𝑅𝑅 𝑅 𝑅𝑅𝑡𝑡 ∙ T（１）

R は電子の数に対するγの数の比、𝑁𝑁𝑡𝑡 は標的の原子の数、T は照射時間である。Geant4 を用いて𝐼𝐼𝑒𝑒 ∙𝑅𝑅、つまり試料に照射されたγ線の数をシミュレーションした。断面積σは TALYS [2] を用いて計算したものを使用した。第６図に Talys で計算した断面積と、24Na の断面積の文献値および 50MeV の電子が制動放射によって放出する ɤ 線のエネルギー分布をまとめた。
TALYS コードとは A.J.Koing らによって開発され、2004 年に公開された汎用核反応理論計算コードである。直接反応、複合核反応、前平衡反応、核分裂反応に対する核反応模型が組み込まれている。
2.5．測定結果とシミュレーションの比較得られた測定結果とシミュレーションの結果を一つにまとめたものを 24Na については第７図に 22Na
については第８図に示す

45

第６図 Talys による断面積と文献値 [3] およびγ線のエネルギー分布
γ線のエネルギー分布の縦軸はスケールしてある。
2.5．測定結果とシミュレーションの比較得られた測定結果とシミュレーションの結果を一つにまとめたものを 24Na については第７図に 22Na
については第８図に示す。

第７図

24Na の生成量の比較(左から試料 1、2、3)

第８図

22Na の生成量の比較(左から試料 1、2、3)

試料 1、2、3 の生成量の比はシミュレーションと測定でよく一致した。24Na は測定値の 30%程大き
く、22Na は測定値の 4 倍程度となった。
Ge 半導体検出器と NaI シンチレータで測定した値は誤差の範囲で一致している。24Na の生成量のシ
ミュレーションでの値は測定値よりも 30%ほど大きかった。これは断面積を見てみると、TALYS で求めた断面積が文献値よりも大きくなっており、また、文献値の誤差も大きい。これらのことから、この差異は誤差の範囲内にあると考えられる。22Na の生成量はシミュレーションでの値が測定値の 4 倍になった。これは断面積のエラーでは説明がつかないので Talys で計算した断面積が大きく見積もられす
ぎていると考えられる。

§３．放射化分布測定実験

46

二回目のビーム照射では、放射化分布の広がりを調べるために、Al ブロックへのビーム照射を行った。
3.1．ビーム照射のセットアップ
ブロックの放射化分布を調べるために第９図のようなセットアップを作った。

第９図 ブロック実験の概略図
このセットアップは Al ブロック（H 100 ㎜、W 100 ㎜、T 20 ㎜）を Al 板（H 10 ㎜、W 200 ㎜、T 200 ㎜）に幅 20 ㎜の隙間を空けてネジ止めし、ビーム下流側に Al 箔（H 100 ㎜、W 90 ㎜、0.05㎜）をクリップによって Al 板に固定した。
今実験では 50MeV 電子ビームを 1 時間このセットアップに照射し、イメージングプレートおよび
NaI、Ge 検出器を用いて Al 箔の放射化分布を測定した。
3.2．放射化分布測定
まず、Al 箔をイメージングプレートに露光し、東北大学サイクロトロン・ラジオアイソトープセンターの RI 棟 3階の IP 室の現像機で現像を行った。その後 Al 箔を 1cm 片に切りビーム照射中心付近を Ge 半導体検出器で測定した。
得られた結果を第１０図に示す。ここではビーム上流方向から置いた順に Al１-Al4 とした。

第１０図 イメージングプレートで得られた結果
3.3．測定結果とシミュレーション結果の比較
イメージングプレート、Ge 半導体検出器、シミュレーションでのビーム上流から見て 1 枚目の Al 箔の放射化分布を一つのグラフにプロットしたものを第１１図に示す。
シミュレーションの分布の半値幅は Ge 半導体検出器での半値幅の 1/2 程度となっている。また、イメージングプレートでの放射化分布は裾が広がっている。これらの原因は究明中である。

47

第１１図 放射化分布の広がり§６．まとめ
大強度電子線形加速器を用いて 27Al 標的に電子ビームを照射し 24Na と 22Na を生成した。その生成量と分布を NaI シンチレーターと Ge 半導体検出器とイメージングプレートを用いて測定した。
Geant4 を用いてシミュレーションを行い、その結果を測定値と比較した。
24Na の生成量のシミュレーションでの値は Ge 半導体検出器での測定値より 30%ほど大きくなった。
これは断面積のエラーの範囲内にあると考えられるので、シミュレーションは測定値をよく再現できていると言える。22Na の生成量のシミュレーションでの値は Ge 半導体検出器での測定値の 4 倍程度となった。これは、断面積のエラーでは説明がつかないので、Talys で計算した断面積が大きすぎるのではないかと考えられる。
放射化分布の広がりは Ge 半導体測定値での測定値がシミュレーションでの値の 2 倍となり、イメー
ジングプレートの分布は裾が広がっていた。これらの原因はいまだはっきりとわかっておらず、原因を究明中である。

参考文献[1] Geant4 website: < http://geant4.cern.ch/>[2] TALYS website: < http://www.talys.eu/>[3] Soviet Physics JETP11(1960)783

48

ELPH Annual Report, Tohoku University (2016)(ELPH Experiment : #2840)

Large Acceptance Multi-Purpose Spectrometer (LAMPS)
Time Projection Chamber (TPC) Prototype Beam Test
H. S. Lee1 , Y. J. Kim1 , M. S. Ryu1 , and J. W. Lee2
1

Rare Isotope Science Project, Institute for Basic Science, Daejeon, 34047, Korea
2

Department of Physics, Korea University, Seoul, 02841, Korea

LAMPS is the nuclear science facility to study a nuclear equation of state via heavy-ion collisions
at RAON. TPC is the main tracking detector of the LAMPS solenoid spectrometer to identify particle
species and reconstruct the momentum of each track with high precision over a large acceptance. The
LAMPS TPC prototype was made for 1/2 size of a real LAMPS TPC. We measured the drift velocity,
diffusion and position resolution to understand the characteristics of the LAMPS TPC prototype byusing a positron beam.

§ 1. Introduction

1.1 Large Acceptance Multi-Purpose Spectrometer (LAMPS)
RAON is the rare isotope (RI) beam accelerator facility in Korea. The motivation of RAON is tounderstand the nuclear structure of exotic nuclei close to drip lines, the astrophysical processes and thedetailed properties of dense nuclear matters. One of the nuclear science facilities at RAON is LAMPS
for the study of a nuclear equation of state (EoS) via heavy-ion collision experiments. Using RI beams
allows us to widely vary and control a neutron to proton ratio of the colliding system. Such a controlled
experiment is possible to explore the isospin dependent part of nuclear matter EoS, known as symmetryenergy, which is an important component of understanding the neutron star, supernova, nuclear synthesis and exotic nuclei near neutron drip lines.
At the end of the In-Flight separator, LAMPS will be located for completing an event reconstruction by
detecting all the particles produced in heavy-ion collisions within a large acceptance angle to measureparticle spectrum, yield, ratio and collective flow of pions, protons, neutrons, and intermediate fragments at the same time. LAMPS consists of a solenoid spectrometer and a forward neutron wall. A Time
Projection Chamber (TPC) and a time-of-flight (ToF) detector will be placed inside cylindrical solenoid
magnet of 0.5 T for charged particle tracking and particle identification. The forward neutron wall will
be made of 8 layers of plastic scintillators for neutron tracking.
1.2 LAMPS TPC
LAMPS has TPC as a main tracking device in the solenoid spectrometer to identify particle species
and reconstruct the momentum of each track with high precision over a large acceptance. Inside of TPC,
micro patterned gas amplifiers such as triple stacks of Gas Electron Multiplier (GEM) are deployed. [1]49

Fig.1.

LAMPS TPC prototype.

The LAMPS TPC is cylindrical with a central axis lying on a beam direction. The length of a gas volume
inside TPC is 1.2 m and its radius is 50 cm. In order to avoid gain saturation due to beam particles, thecylindrical hole with radius of 15 cm is made along the beam axis. The readout PAD is located at theend of the cylinder and is segmented into eight identical trapezoidal sectors in azimuthal angles. Eachsector is equipped with three GEM foils for amplifying the charge signal which is composed by 2 mm
gap between GEM foils. The nominal target position is a quarter of the total length of the gas volume(30 cm) from the upstream face of TPC to enlarge the geometrical acceptance at mid-rapidity. Therefore,
TPC covers the range of 25o to 126o in the polar angle of a laboratory system.
The LAMPS TPC prototype was designed for 1/2 size of real LAMPS TPC in terms of an outer radius
and a drift length but an inner radius of the cylindrical hole is the same to the real LAMPS TPC. The
LAMPS TPC prototype will give us various information : drift velocity, performance of field cage, andposition resolution of different readout PAD designs. Figure 1 shows the LAMPS TPC prototype, a field
cage, readout PAD and a GEM. Two different designs of readout PADs (3 × 10 mm2 , 4 × 15 mm2 ) areinstalled.

§ 2. Experiment

The purpose of this experiment is to understand the characteristics of the LAMPS TPC prototype

with a positron beam. We measured a drift velocity by modulating an electric field of the field cage
and the performance of two different readout PAD designs (4 × 15 mm2 and 3 × 10 mm2 ), which werecompared for two different gas mixtures : P-10 (Ar 90% + CH4 10%) and ArCO2 (Ar 90% + CO2 10%).

Figure 2 shows an experiment setup at the ELPH beam line. The LAMPS TPC prototype is placed at
the beam line and on the lab jack to change a beam injection height at TPC. To define beam trigger, 6
trigger counters are placed in the front and back side of the LAMPS TPC prototype. At the front, two

50

Fig.2.

ELPH experiment setup.

scintillators whose size is 1 cm width are installed to define 1 × 1 cm2 beam size. 4 cm scintillators are

installed to make a trigger signal by passing the beam in the back of TPC. Two large scintillators whose
size is 20 × 20 cm2 are placed just in front and back side of TPC.

Two different PADs are installed in the LAMPS TPC prototype. We tested 4 × 15 mm2 PAD in the

LAMPS TPC prototype, and the other 3 × 10 mm2 PAD was tested by using a small GEM test chamber
next to the LAMPS TPC prototype as shown in Fig. 2.

A trigger signal is defined by the coincidence of 6 scintillators. We took VME data for scintillator counters
and TPC data by using a different DAQ program at the same time. In order to synchronize two different
DAQs, we made the gate signal with a trigger signal from scintillating counters, trigger ready from TPC
DAQ and busy signal from TPC DAQ.
Figure 3 shows one example of beam event display on TPC. The top figures are raw signals of each PAD
Signal of PAD1

Signal of PAD2

4000

4000

3500

3500

3000

3000

2500

2500

2000

2000

1500

1500

1000

1000

500
0

500

0

100

200

300

400

0

500

0

100

200

x vs y of PAD1

300

400

500

x vs y of PAD2
1200
1400

60

1200

40

1000

20

800

0

60
1000
40
20

800

0

600

− 20

600

− 20

− 40

400

− 40

− 60

200

− 60

400

− 220

− 200

− 180

− 160

− 140

− 120

− 100

0

Fig.3.

200

100

120

140

160

180

200

220

0

Event display of positron beam.

51
after TPC front-end electronics and the bottom figures show the beam tracking on the two PADs. Since
the beam passes through the same height of the LAMPS TPC prototype, all signals of PAD are locatedat the same timing. Right figure shows 3 dimensional event display.
We have taken data for two different gases for 2 days. On the first day, we have tested with different
electric field of the field cage from 115 V/cm to 155 V/cm with P-10 gas. Also, we varied a beam injection
height (20.24 cm, 35.24 cm and 50.24 cm) in the LAMPS TPC prototype. On the next day, we have tested
with ArCO2 gas by changing the beam injection height. In this case, we fixed an electric field at 170
V/cm.

§ 3. Analysis and Result
3.1 Drift Velocity

TPC is a very good 3 dimensional tracking detector. X and Y positions are defined by the readout
PAD positions. Z position is defined by the drift time of electron along the field cage. We measured adrift velocity as a function of 5 electric fileds (115 V/cm ∼ 155 V/cm). To calculate a drift velocity, wemeasured 3 different beam injection heights in the LAMPS TPC prototype. Figure 4 shows the measured
drift velocity as a function of electric fields. Red points are the measured values by using the positron
beam at ELPH. Blue one is from the muon test in the lab and black is based on garfield++ calculationfrom the gas table. In the P-10 gas, the maximum drift velocity is 5.26 cm/µs with positron beam at anelectric field of 155 V/cm. The drift velocity of ArCO2 gas is 1.07 cm/µs at an electric field of 170 V/cm.
Since a real LAMPS TPC will have 120 cm field cage, the drift time with a full range will be around 23µs if we use P-10 gas with 155 V/cm electric field. Since we need the drift velocity faster than 6 cm/µs
in order to record complete information within time range of electronics which cannot be achieved using
P-10, we tested P-20 (Ar 80% + CH4 20%) gas mixture. As shown in Fig. 4, by using P-20 gas, we could

PAD2

8

σ2track (mm2)

Drift Velocity (cm/us)

measure the drift velocity of 6.7 cm/µs at the 205 V/cm electric field.

7

6

5

χ2 / ndf
0.07584 / 1
p0
4.33 ± 1.716
p1
0.182 ± 0.05373

30

25

70
60
50

20

40

4

15

ELPH P10
330

ELPH ArCO2
muon P102

10muon P20

20

Sim. P10
1

5

Sim. P20

10

Sim. ArCO2
0

100

125

150

175

200

225

250

275

300

E field (V/cm)

Fig.4.

Drift Velocity as a function of electricfield.

00

Fig.5.

10

20

30

40

50
60
Drift distance (cm)0Square of charge cloud width as a function of position beam height.

52
3.2 Diffusion
One of the most important characteristics of TPC is the position resolution. The position resolution
is determined by various parameters of TPC : gas diffusion, PAD size and so on. Since the diffusion
coefficient represents a spread of the electron cloud, the diffusion coefficient of the chosen gas is themost important factor to determine the position resolution.
The spread of the charge cloud increases along the drift distance (Z) due to collisions with gas atoms andmolecules. Therefore, the width of the track (σtrack ), which is perpendicular to the track, is a function ofdrift distance Z : [2]2= D 2 Z + σ02
σtrack(1)

where D is a transverse diffusion coefficient and σ0 is a coefficient due to the amplification system (triple
GEM system of the LAMPS TPC prototype).
Figure 5 shows the width of the charge cloud (σtrack ) as a function of the drift distance (Z) at an electricfield of 155 V/cm. In the linear fitting, the slope (p1) corresponds to a transverse diffusion coefficient.
√
The diffusion coefficient was obtained as 426 µm/ cm.
3.3 Position resolution
We have tested two different size PADs : 4 × 15 mm2 in the LAMPS TPC prototype and 3 × 10 mm2

in the small GEM test chamber. Figure 6 shows the residual distribution along the distance between the
beam track and the hitting position on the PAD. We have measured position resolutions for the P-10 gas
condition. The left distribution is for the 4 × 15 mm2 PAD and its position resolution is 605.6 µm. The
right one is for the 3 × 10 mm2 PAD and 227.5 µm position resolution.

3500

33380

Mean

−0.1781

3000

RMS

2500

Constant

χ2 / ndf

2000

1.251

res2_2

6000
CountsCountsres2_0
Entries

5000

70.38 / 73569 ± 31.6

Mean

−0.2404 ± 0.0050

Sigma

0.6056 ± 0.0060

1500

4000

Entries

24322

Mean

−0.5103

RMS

2.656

χ2 / ndf

1683 / 7
5981 ± 73.1

Constant

3000

Mean

−0.01105 ± 0.00193

Sigma

0.2275 ± 0.0025

2000

1000
1000

500
0
−10

−5

Fig.6.

0

5

10

Residual (mm)

0
−10

−5

0

5

10

Residual (mm)Residual distribution of PAD 4 × 15 mm2 (left) and 3 × 10 mm2 (right).

§ 4. Summary

LAMPS is one of the experimental facility for nuclear physics at RAON. We have been developing

the LAMPS TPC which is a main tracking detector of the LAMPS spectrometer. The LAMPS TPC

53
prototype was developed to study a design of the LAMPS TPC with triple GEM system. We have tested
the LAMPS TPC prototype with positron beam at ELPH. The maximum drift velocity of P-10 gas is 5.26
cm/µs at 155 V/cm electric filed and ArCO2 gas is 1.07 cm/µs at 170 V/cm. The drift velocity was tested
using a P-20 gas in order to achieve a requirement of the TPC elctronics and is obtained with 6.7 cm/µs.
√
Transverse diffusion coefficient is 426 µm/ cm with P-10 gas. Position resolutions are 605.6 µm for 4 ×

15 mm2 PAD and 227.5 µm for 3 × 10 mm2 , respectively.

Acknowledgment
The authors would like to thank ELPH accelerator staff for providing the stable beam. We deeply
appreciate M. Miyabe and H. Shimizu for supporting beam test. This work was supported by the Rare
Isotope Science Project and by the Institute for Basic Science, with funding provided by the Ministry of
Science and the National Reference Foundation (NRF) of Korea (2013M7A1A1075765).

References[1]

F. Sauli : Nucl. Instrum. Methods. A805 (2016) 2.

[2]

R.K. Carnegie et al.: Nucl. Instrum. Methods. A538 (2005) 372.

54

ELPH Annual Report, Tohoku University (2016)(ELPH Experiment : #2864)

Performance study of prototype hodoscope for new photon
tagging system STB TaggerIIs
M.Iwasa1 , M.Sasaki1 , Y.Inoue2 , T.Ishikawa2 , H.Kanda3 , J.Kashiwagura1 ,M.Miyabe2 , N.Muramatsu2 , T.Ono1 , M.Sasagawa2 , Y.Seki1 , R.Shirai2 ,H.Shimizu2 , Y.Sugihara1 , Y.Tajima1 , A.O.Tokiyasu2 , H.Wauke1 ,and H.Y.Yoshida112Department of Physics, Yamagata University, Yamagata, 990-8560

Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826
3

Research Center for Nuclear Physics, Osaka University, Ibaraki, 567-0047

A new photon tagging system that called STB TaggerIIs, is developed in progress at ELPH for
FOREST experiments. STB TaggerIIs consists of MWDC and hodoscope. The hodoscope can specify thegenerated time of photons with good resolution. We made a prototype hodoscopes and measured thetime resolution using positron beam in December 2016 and February 2017. The time resolutions of all
prototypes with amplifier were less than 190 ps. From this results, we decide to use the single-sided
readout system of the STB TaggerIIs hodoscope.

§ 1. Introduction

We are developing a new photon tagging system (STB TaggerIIs) for FOREST experiments. FOR-

EST experiments are used photon beam. When inserting carbon fiber into the circulating electrons in
BST electron ring, bremsstrahlung radiation occurs and photon beam are generated. The photon tagging
system is used to identify a photon and and determines the energy. Fig. 1 is a illustration of STB TaggerIIs. Recoil electrons are bent inwards by the bending magnet. STB TaggerIIs detects recoil electrons
and tags a photon beam. The energy of a photon is given by the following equation. [1].
Eγ = e − erecoil(1)Here, e, erecoil , and Eγ are the energy of the circulating electrons, recoil electrons and photons.
STB TaggerIIs consists of a MWDC and a hodoscope. The MWDC is worked to detect recoil electron
trajectories and calculates momentum with high accuracy. The hodoscope is worked to separate a bunchof photon beams with good time resolution. The interval time of the beam bunch is 2 ns, and in order
to identify the beam bunch, the time resolution of the hodoscope is less than 200 ps. To archive therequirement, we made prototypes of the hodoscope and measured the time resolution.
1.1 Hodoscope
The prototype hodoscopes are combination of Multi Pixel Photon Counter (MPPC) and plastic scintillator. The hodoscope must not be affected by the magnetic field, because it is installed in the bending

55
Bending Magnet

TaggerIIs
Hodoscope
MWDC

electron beamrecoiled electron
gamma ray
Radiator

Fig.1. Illustration of TaggerIIs.

magnet. The hodoscope has 60 scintillators. The size of the scintillators are 5–30 mm width, 30 mm
height, 5 mm thickness. In order to make the same counting rate and below 500kHz, the width of scintillators were decided from 5 mm to 30 mm at intervals of 5 mm. Therefore the width of scintillator
to detect high energy recoil electron is 5 mm, and to detect low energy is 30 mm. The height of thescintillators are 30 mm, these are as same as the window height of the MWDC. The reflection sheets ofthe scintillators are used Teflon.

§ 2. Measurement of time resolutions
2.1 Experimental condition

The experiment was carried out at ELPH positron beam line in December 2016 and February 2017.
We studied 5 mm and 30 mm width scintillator. We compared with single-sided and dual-sided readout.
5 mm width scintillators were studied single-sided readout, dual-sided individual readout, and dual–
sided sum readout.(Fig.2) 30 mm width scintillator was studied dual-sided individual readout with andwithout amplifier. The readout modules were one MPPC for 5 mm width scintillators, and parallel
connected six MPPCs for 30 mm width scintillators. Applied voltage of MPPC were changed from 55.5
V (break down voltage + 3 V) to 60.5 V at intervals of 1 V. Threshold were studied 10 mV (without
amplifier) , 50 and 100 mV ( with amplifier).

MPPC

Fig.2. Left : single–sided readout. Middle : Dual–sided sum readout. Right : dual–sided individual readout.

56
2.2 SetupFig. 3 shows the experiment set up. T0 is 5 mm × 20 mm × 20 mm plastic scintillator with single

photomultiplier readout to use for trigger start counter. T1 is 5 mm × 50 mm × 50 mm plastic scintillator

with dual-sided photomultiplier readout to measure time. The prototype hodoscopes are set between T0
and T1. The signal from hodoscope divided into two lines. One enters into an ADC module through acable delay, the other enters into TDC module. The trigger is coincidence of T0 and T1. Fig. 4 shows
logic data taking system for the measurement and Tabel 1 shows the specification of counters.

Fig.3. Set up of the measurement.

Fig.4. Schematic illustration of the data taking system.

Table 1. Characteristics of the counters.
CounterStart Counter T0
Timing Counter T1
MPPCType number
R4125DMOD
H6410
S13360-3050PE

Operating voltage(max) [V]
1500 (1800)
2000(2700)
55.5

Scintillator size [mm3 ]5(W)×20(H)×20(T)
5(W)×50(H)×50(T)
5(W)×30(H)×5(T) , 30(W)×30(H)×5(T)57§ 3. Results

3.1 ADC correcion
For ADC correction, the mean and error of TDC data is made by each bin of ADC, and fitted withcorrection function. The correction function is as follows.
T = p0 + √

p1

(2)

ADC

Fig. 5 shows results of that.

Fig.5. A correlation plot of TDC and ADC. Left: Before correction. Middle : Profile plot andfitting result. Right : After correction.

3.2 Time resolutions
After time correction, the time resolutions of prototype scintillators are obtained. Fig. 6 shows theresults of 5 mm wide scintillator.
Table 2 and 3 show the time resolution with same bias voltage 56.5 V. The time resolutions of dual–
sided sum readout are about 150 ps, better than single–sided readout. But both results are less than 190
ps, and lower than required resolution 200 ps. The time resolutions without amplifier, does not change
in any readout method.
These are around 170 ps, and are shown in Fig. 7.
Without AMP, the sum read out in parallel from both sides and the average for each read and time
are the same time resolution. Both time resolutions are around 170 ps. Figre 7 represents it.
Table 2 shows the rime resolution with the same bias. Here, we show data of 56.5 V (operating
voltage +1 V) where fitting worked well for any data.
Table 2. The time resolution of 5 mm width scintillator with amplifier (bias voltage=56.5 V)
Threshold [mV]
Readout
Time resolution [ps]single–sided
186±4

100
dual–sided sum
149±6

single–sided
172±4

50
dual–sided sum
157±6

3.3 Bias voltage dependence of time resolution
Fig.8–10 shows the the bias voltage dependency of the time resolution. Fig.8 shows the results of
5mm width scintillator with amplifier, and Fig.9 shows without amplifier. The time resolutions are worse

58

Fig.6. Left 2D histograms are the profile plot, and right histograms are time resolution. Uppers
are the results of single–sided readout, and lowers are dual–sided sum readout. (Uppers: TDC 1 ch = 25.59 ps. Lowers : TDC 1 ch = 25.56 ps)

Fig.7. The time resolutions of dual-sided sum readout (left) and individual readout average(right) without amplifier, the thresholds are 10 mV.

Table 3. The time resolution of 5 mm width scintillator without amplifier (bias voltage=56.5 V)
Threshold [mV]
Readout
Time resolution [ps]10
single–sided
161±2

sum
168±4

dual–sided
individual
average
right
left
172±5
203±6 236±659Table 4. The time resolution of 30 mm width scintillator.
Threshold [mV]
amplifierTime resolution [ps]100with amplifier
165±4

10
without amplifier
233±6near the operating voltage (breakdown voltage +3 V = 55.5 V) . The other side, the time resolutions areslightly worse that the bias voltage is over the operating voltage + 3 V. FIg.10 shows the time resolutionof 30 mm width scintillator. To satisfy the requirement, the readout of 30 mm width scintillator is needed
amplifier.

5 mm scintillator with amplifier
time resolution [ps]single-sided readout (thr100 mV)
single-sided readout (thr50 mV)
dual-sided sum (thr100 mV)
dual-sided sum (thr50 mV)

400
350
300
250
200
150
53

54

55

56

57

58

59

60
voltage [V]

Fig.8. The bias voltage dependence of 5 mm width scintillator with amplifier.

60

time resolution [ps]5 mm scintillator without amplifierdual-sided individual readout (average)260

dual-sided sum (thr10 mV)
single-sided readout (thr10 mV)

240

220
200

180

160
56

57

58

59

60
voltage [V]

Fig.9. The bias voltage dependence of 5 mm width scintillator without amplifier.

time resolution [ps]30 mm scintillator
with amplifier

280

without amplifier

260
240
220
200
180
160
56

57

58

59

60
voltage [V]Fig.10. The bias voltage dependence of 30 mm width scintillator.

61§ 4. Summary

The new photon tagging device, STB TaggerIIs is developed in ELPH. This device consists of MWDC

and hodoscope. The requirement of the hodoscope is that the time resolution is less than 200 ps. We
made prototype hodoscope from plastic scintillator and MPPC. We studied three types of signal readout
methods, single–sided readout, dual–sided individual readout, and dual–sided sum readout. And wecompared each readout method with and without amplifier. The time resolution with dual–sided sum
readout is equivalent to dual–sided individual readout. In addition, we compared the time resolution
with AMP present and without AMP. The time resolutions of all situation with amplifier are less thanrequired resolution, 200 ps. As a result, we decide the readout system of STB TaggerIIs hodoscope isused single–sided readout.

Acknowledgment
The authors would like to thank our collaborators in ELPH for technical assistance with the experiments.

References[1]

M. Sasaki et al.: ELPH Annual Report 2015 (2016) 45.

62

ELPH Annual Report, Tohoku University (2016)

Photon beam asymmetry measurement for the η
photoproduction at SPring-8 BGOegg experiments
Norihito Muramatsu1 , Toshikazu Hashimoto2 , Jung Keun Ahn13 ,Wen-Chen Chang5 , Jia-Ye Chen6 , Schin Daté4 , Toshiyuki Gogami3 ,Hiroya Goto3 , Hirotomo Hamano3 , Qing Hua He1 , Kenneth Hicks7 ,Toshihiko Hiraiwa3 , Yuki Honda1 , Tomoaki Hotta3 , Hiroyuki Ikuno3 ,Yosuke Inoue1 , Takatsugu Ishikawa1 , Igal Jaegle8 , Ja Min Jo13 ,Yuuto Kasamatsu3 , Hitoshi Katsuragawa3 , Satoshi Kido1 , Yukiyoshi Kon3 ,Shinichi Masumoto9 , Yuji Matsumura1 , Katsumasa Miki12 , Manabu Miyabe1 ,Keigo Mizutani2 , Taiki Nakamura12 , Takashi Nakano3 , Masayuki Niiyama2 ,Yuki Nozawa2 , Yuji Ohashi4 , Haruo Ohkuma4 , Hiroaki Ohnishi10,3 ,Takeshi Ohta3 , Masaya Oka3 , Kyoichiro Ozawa11 , Mizuki Sasagawa1 ,Takuya Shibukawa9 , Hajime Shimizu1 , Rintaro Shirai1 ,Ken’ichiro Shiraishi1 , Yorihito Sugaya3 , Mizuki Sumihama12 ,Shinsuke Suzuki4 , Shintaro Tanaka3 , Atsushi Tokiyasu3 , Natsuki Tomida2 ,Nam Tran3 , Yusuke Tsuchikawa1 , Hirohito Yamazaki1 , Ryuji Yamazaki1 ,Yuka Yanai3 , Tetsuhiko Yorita3 , and Masaru Yosoi3
1

Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826,
Japan
2
3

4

Department of Physics, Kyoto University, Kyoto 606-8502, Japan

Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan

Japan Synchrotron Radiation Research Institute (SPring-8), Sayo, Hyogo 679-5198, Japan
5
6
7

Institute of Physics, Academia Sinica, Taipei 11529, Taiwan

National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan

Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA
89University of Hawaii at Manoa, Honolulu, HI 96822, USA

Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
10

11

RIKEN Nishina Center, Wako, Saitama 351-0198, Japan

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization(KEK), Tsukuba, Ibaraki 305-0801, Japan
12
13

Department of Education, Gifu University, Gifu 501-1193, Japan

Department of Physics, Korea University, Seoul 02841, Republic of Korea

The single η photoproduction from a proton target is a good probe to study the N ∗ resonances
which include ss̄ content. Since the isospin of the η meson is zero, it does not couple with ∆∗ resonances.
Usually the N ∗ resonance search is done by measuring the total cross section. However, the excitedresonance states typically have large widths, and they may be overlapped with the possible influence of

63

Fig.1.

The slat number dependence of the IPS efficiency for proton detection. The IPS slat
number corresponds to the azimuthal angle around the LH2 target.

interferences. Therefore, the measurement of the photon beam asymmetry, which is represented by theinterferece terms of helicity amplitudes, is a strong tool to decompose the N ∗ resonances.
The η → γγ decay is detected at the BGOegg electromagnetic calorimeter, which is composed of
1,320 BGO crystals covering the polar angle range from 24 to 144 degrees [1, 2]. The proton in the
final state is detected at the planar drift chamber (DC) or the BGOegg calorimeter with the charge
identification by the inner plastic scintillators (IPS). The DC is placed in the forward acceptance holecorresponding to the polar angles less than 21 degree. The experimental data was collected in thelatter half of 2014 (2014B cycle) by irradiating the 1.3–2.4 GeV tagged photon beam [3] onto the liquidhydrogen (LH2 ) target [4] at the SPring-8 LEPS2 beamline.
The event selection has been done in two ways: One is the simple selection by the combination ofmass spectra and kinematical cuts [5]. The η meson and the proton are identified by the 2γ invariant
mass and the p(γ,η) missing mass, respectively. The kinematical angle consistency between the detected
proton track and the missing momentum calculated from the 4-momentum of the η meson was also
required to reduce backgrounds. The other method of the event selection was done by removing low χ2probability events after the kinematical fit with the constraints of the 4-momentum coservation and theη mass.
The photon beam asymmetry Σ is defined from the production rate modulation depending on theazimuthal angle difference between the reaction plane and the linear polarization vector of the photon
beam. In order to obtain the information about the N ∗ resonance decomposition, the photon beam
asymmetry was measured in 5 bins of the CM energy and 4 bins of the η emission polar angle at the
CM frame. During the measurement of the photon beam asymmetry, various checks were performed forsystematics confirmations. For example, Figure 1 shows the efficiencies of IPS, which is segmented into
30 long slats in the azimuthal direction. It has been confirmed that there is no azimuthal dependence

64
for the charge identification, which can possibly make an artificial asymmetry. The data collection was
done with the two perpendicular directions of photon beam linear polarization, so that any geometricaleffect to the photon beam asymmetry can be found. Such effect has not been observed.
Figure 2 shows the azimuthal distribution of the η meson signal counts, measured based on theevent selection by the mass spectra and kinematical cuts. In order to extract the η signal counts, thesignal and background template shapes were simultaneously fitted to the 2γ invariant mass and missing mass spactra. The photoproduction processes of π 0 π 0 p, ηπ 0 p, and ωp final states were taken into
account as backgrounds. Even after reducing backgrounds enough with the tight cut making the signal
acceptance one third, the strength of azimuthal asymmetry was confirmed to be unchanged.
Figure 3(a) shows the result of the beam asymmetry measurement at the lowest energy bin. In
this energy region, the CB-ELSA collaboration has reported a comparable result [6], showing the goodconsistency with the BGOegg measurement. In contrast, the results in the higher energy region arenew. Here we show the beam asymmetries for the highest energy bin in Fig. 3(b). Apparently, the polar
angle dependence is different from the lowest energy bin, and this information must provide a strong
constraint on the N ∗ decomposition. The final results will be shown with the differential cross section
measurement.

References[1]

N. Muramatsu, ELPH Report 2044-13 (2013) or arXiv:1307.6411.

[2]

T. Ishikawa et al., Nucl. Instr. Meth. A837, 109 (2016).

[3]

N. Muramatsu et al., Nucl. Instr. Meth. A737, 184 (2014).

[4]

N. Muramatsu et al., ELPH Annual Report Vol.5, 106 (2015).

[5]

T. Hashimoto et al., Oral presentation, JPS meeting (Osaka), 19 Mar 2017.

[6]

D. Elsner et al., Euro. Phys. J. A33, 147 (2007).

65

Fig.2.

The yields of γp → ηp depending on the azimuthal angle of the η meson relative to thelinear polarization vector of the photon beam. The case of the lowest energy bin andthe most backward bin is plotted here. The black data points show the result of thestandard template fit, while the red points indicate the yields after the very tight cutson the invariant and missing masses. The tight cut result is scaled to the standard cut
measurement.

Fig.3.

The photon beam asymmetries for γp → ηp at (a) the lowest and (b) the highest energy
bins. The red (green) points indicate the result of BGOegg (CB-ELSA) experiments.

66

ELPH Annual Report, Tohoku University (2016)

Pulse laser test for the backward Compton scattering
at the SPring-8 LEPS beamline
Norihito Muramatsu1 , Hitoshi Katsuragawa2 , Takashi Nakano2 ,Yuji Ohashi3 , Schin Daté3 , and Yosuke Orii4
1

Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826,
Japan
2

3

Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan

Japan Synchrotron Radiation Research Institute (SPring-8), Sayo, Hyogo 679-5198, Japan
4

Spectronix Corp., Suita, Osaka 564-0062, Japan

High energy photon beams are available at SPring-8 LEPS and LEPS2 beamlines by the backward
Compton scattering of ultraviolet laser light from 8 GeV electrons in the storage ring [1]. They areused to produce various hadrons and to investigate their natures. Currently, the intensity of the tagged
photon beam in the energy range below 2.4 GeV reaches a few MHz by the simultaneous injection ofa few laser beams. While the photon beam has several specific features as a hadron beam, there isa disadvantage for the low interaction rate with a target material to produce hadrons. Therefore, themethod to increase the beam intensity up to 5–10 MHz has been strongly desired.
One way to upgrade the beam intensity is the use of the pulse laser whose output timing is forced
to be synchronized with the electron beam bunches. While the electron beam bunch exists at 1.966 nseceach RF packets with various filling patterns, the lasers are currently operated in the CW or quasiCW mode, emitting the laser light even at the time periods when the electron bunches do not exist
at the interaction region. Recently, the pulse laser whose emission timing pattern can be generated
intentionally with external trigger inputs is being available from Spectronix Corp. By using this pulse
laser, the output power corresponding to a few tens W in the CW mode can be concentrated only at the
moments when the electron bunches exist.
In December 2016, we temporarily installed a demonstration machine of 355 nm ultraviolet pulse
laser with a few hundreds mW output at the LEPS beamline. The external trigger signal was generated
from the accelerator RF signals with prescaling. Pulsed laser light was emitted with a set frequency
after accepting the trigger signal. We chose the SPring-8 beam cycle whose electron filling pattern was
so-called “A-mode”, so that the laser was emitted at every 23.6 nsec, corresponding to the electron beam
bunch interval. The delay time of the external trigger signal input was also adjusted because the pulsed
light must meet with an electron beam bunch optimally at the laser focus point or the interaction region.
Therefore, the NIM-standard circuit for the time delay with a 0.5 nsec precision was set at the external
trigger signal line.
Figure 1 shows the result of photon beam intensity measurement with the pulse laser. The horizon-

67

Fig.1.

The intensity modulation of the tagged photon beam depending on the delay time of theexternal trigger signal for the pulse laser. The sudden change at 14 nsec corresponds tothe edges of the straight section of the storage ring.

tal axis represents the amount of delay. Here, the photon beam intensity was measured by the tagging
counter, which detected recoil electrons from the backward Compton scattering. The intensity modulation depending on the delay time was observed as expected. In order to compare with the beam intensity
in the case of CW laser injection, the emission frequency was slightly changed from the rate of 23.6 nsec
intervals for asynchronous scattering, while the laser output power was kept. The asynchronous scattering did not show the intensity modulation pattern with the variation of delay. From the comparison of
the two injection methods, we observed the pulse laser injection with the optmized frequency and delay
provided about two times larger beam intensity compared with the CW laser case.
Based on the test with the demonstration machine, the effectiveness of the pulse laser injection was
confirmed well. It has been found that the enhancement factor of ∼2 can be improved by achieving theideal laser focus. In addition, the pulse laser emission can be suitably arranged even for the complicatedelectron filling patterns by programming the external trigger signal timings at a function generator.
Further tests will continue for practical application.

References[1]

N. Muramatsu et al., Nucl. Instr. Meth. A737, 184 (2014).

68

ELPH Annual Report, Tohoku University (2016)

Electron scattering with stable nuclear targets at SCRIT
electron scattering facility
K. Tsukada1 , K. Adachi3 , A. Enokizono3 , T. Fujita3 , M. Hara2 , M. Hori3 ,T. Hori2 , S. Ichikawa2 , K. Kurita3 , T. Ohnishi2 , T. Suda1 , T. Tamae1 ,M. Togasaki3 , N. Uchida3 , M. Wakasugi2 , M. Watanabe2 , and K. Yamada3
1

Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826
2

RIKEN Nishina Center for Accelerator-Based Science, Wako, 351-0198
3

Department of Physics, Rikkyo University, Tokyo, 171-8501

Electron scattering off stable nuclei, 132 Xe and 208 Pb were performed at SCRIT electron scattering
facility as commissioning of the facility in 2016. For both targets, the diffraction pattern on the reaction cross section were successfully measured and information of the charge density distributions wereextracted. Here, some results for 132 Xe and 208 Pb targets are reported.

§ 1. Introduction

The SCRIT (Self-Confining Radioactive Isotope Target) [1] electron scattering facility have been

constructed at RIKEN to realize electron scattering off unstable nuclei as reported in previous reports [2,3]. This year, commissioning studies of spectrometers and target ion transportation systems have been
performed with several stable targets. Note that the results for the 132 Xe target is already published [4].

§ 2. Experimental Apparatus
2.1 overview of the facility

Figure 1 illustrates the SCRIT electron scattering facility. The facility consists of a 150-MeV racetrack microtron (RTM), an electron storage ring (SR2) equipped with the SCRIT, an electron-beam driven
RI separator for SCRIT (ERIS) [5], a fringing-RF-field-activated ion beam compressor (FRAC) [6], anda window-frame spectrometer for electron scattering (WiSES), and a luminosity monitor (LMON). The
150 MeV-electrons from RTM are stored and accelarated in SR2. During the electrons circulating, target
ions are mass-separated and delivered into SCRIT by ERIS and FRAC, and then scattered electrons aremeasured by WiSES. Details of the facility are found elsewhere [7, 8].
2.2 Target
For the commissioning experiment, the target nuclei were not provided from the ISOL system of
ERIS but extracted from natural materials. The natural xenon gas from a gas bottle was introduced at
an entrance branch of the ERIS system, and 132 Xe ions were extracted by a function of ERIS. For the

69

RI g
en
(ISO erator
L)

ERIS
SR2

FRAC

LMon

SCRIT

WiSES

Fig.1.

Overview of the SCRIT electron scattering facility.

lead target, natural lead was installed at the head of the ERIS and heated up to 300◦ . Then, 208 Pb ionswere separated from the vapor of the lead by ERIS.
Since 208 Pb is one of the most extensively investigated stable nuclei and the form factor is precisely
derived by electron scattering [9], it is the best target to check the spectrometer performance. On theother hand, although 132 Xe is a stable nucleus and the root-mean-square radius is evaluated from themeasurement of X-rays from muonic atoms [10], electron scattering has never been performed. This
work is, therefore, the first to determine the charge density distribution of 132 Xe.
The target ions were stored in the SCRIT for a few hundred ms and ejected to refresh the target
quality because the amount of the residual gas ions also increased due to the ionization and trapping by
the electron beam. The SCRIT operation with and without target ions (IonIN/IonOUT) were alternatedfor the comparative measurement and the background subtraction. The trapping times were 240 msec
for the 132 Xe target and 990 msec for the 208 Pb target experiment. In the present analysis, however, thefirst 240 msec to the 990 msec trapping time was used even for the 208 Pb target because it was foundthat the time evolution of the amount of residual gas ions was influenced by the amount of the target
ions and the background subtraction method did not work correctly for the rest of the time. The interval
among the trapping times was fixed to be 10 ms.

§ 3. Run summary

Table 1 shows run summaries for the series of the commissioning with 132 Xe and 208 Pb targets in

2016. Achieved averaged-luminosities are also listed in the table. The number of ions introduced wasabout 108 particles/pulse, and the achieved lumionsities were around 1027 cm−2 s−1 on average.

§ 4. Data analysis

Details of the data analysis are explained elsewhere [2–4]. Figure 2 shows the differential crosssections multiplied by luminosity for elastic electron scattering off 208 Pb. By changing the electron
beam energy, a wide range of momentum transfer can be covered. The line represents a phase shift
calculation [11] with the nuclear charge density distribution modeled as a sum-of-Gaussian function [9].

70Table 1. Run Summary Table. The irradiation time corresponds to the total time of IonIN conditions. The duty is defined as, duty = TIonIN /(TIonIN + TIonOut + 2 ∗ TInterval ).
The luminosities are averaged values evaluated by WiSES assuming a nuclear charge
density distribution.
Ee [MeV]
151
201
301
151
201
301

target
132
Xe
132
Xe
132
Xe
132
Xe
208
Pb
208
Pb
208
Pb

Date
19-22/Jan
8-10/Feb
6-14/Apr
2-13/Jun
19-23/Jul, 1-2/Aug,6/Aug
23-25/Jul, 2-4/Aug
25/Jul-1/Aug, 4-5/Aug

Irradiation time [sec]1.9×104
7.8×103
1.3×105
1.9×105
6.7×103
5.0×104
1.7×105

Duty [%]
49.5
48.0
48.0
48.0
49.5
49.5
49.5

Luminosity [/cm2 /s]
8.7×1026 ± 2.0%
1.1×1027 ± 2.5%
1.1×1027 ± 1.8%
1.6×1027 ± 8.1%
2.5×1027 ± 5.7%
1.0×1027 ± 5.9%
1.3×1027 ± 6.8%

The luminosity is considered as a fitting parameter in the present analysis because the study of theLMon to determine the absolute value of luminosity is underway. The momentum-transfer dependence
is well reproduced by the calculation.
Figure 3 shows the plot for elastic electron scattering off 132 Xe. The number of introduced target ionsand the achieved luminosity were similar to those for 208 Pb. The parameters of a two-parameter Fermi
distribution are determined by comparing our data and a calculation. The lines for elastic scattering arecalculated with the best values of a two-parameter Fermi distribution. The contamination of inelastic
scattering which is calculated with a distorted wave Born approximation code FOUBES [12, 13] using
a transition density distribution of the ground state to the first 2+ state [14] is negligibly small, as
shown in the figure. By changing parameters, radius C and diffuseness t, of the two-parameters Fermi

L dσ [(cm-2s-1)(cm2sr-1)]
dΩ

+0.28
distribution, the most probable values are firstly extracted to be C=5.42+0.11−0.08 fm and t=2.71−0.38 fm , and 1/2[4].
resulting r 2=4.79+0.12−0.10 fm

102

208

Exp. (Ee =151MeV)

Pb target

Exp. (Ee =201MeV)

10Exp. (Ee =301MeV)DREPHA

1

10

-1

10-2

Preliminary

10-30.4

0.6

0.8

1

1.2

q

1.4 -1[fm ]eff

Fig.2.

Differential cross sections of 208 Pb(e,e) multiplied by the luminosity for the effective
momentum transfer at Ee =151, 201, and 301 MeV. The line is a phase shift calculation
with the nuclear charge density distribution modeled as a sum-of-Gaussian function [9].

§ 5. Conclusion and future prospects

The SCRIT electron scattering facility has been constructed to realize electron scattering off unsta-

ble nuclei. In 2016, several commissioning experiments with stable nuclear targets have been preformed.

L dσ [(cm-2s-1)(cm2sr-1)]
dΩ

71

102
10
1
-1
10
10-2
10-3
10-40.4

132

Exp. (Ee=151MeV)
Exp. (Ee=201MeV)
Exp. (Ee=301MeV)
2-param. Fermi
inela. (2+)

Xe target

0.6

0.8

1

1.2

q

1.4

eff

Fig.3.

[fm-1]

Differential cross sections of 132 Xe(e,e) multiplied by the luminosity for the effective momentum transfer at Ee =151, 201, and 301 MeV. The lines are a phase shift calculation
with the nuclear charge density distribution modeled as a two-parameter Fermi distribution (solid) and contributions of inelastic scattering calculated by a beyond relativistic
mean field theory [14] (dashed).

The momentum transfer distributions of 208 Pb were well reproduced by a calculation with the charge
density distribution which was precisely determined ever. Furthermore, from the momentum transfer
distribution of 132 Xe, nuclear charge density distribution is firstly extracted by changing parameters of
the two-parameters Fermi distribution.
Following this successful experiments, elastic electron scattering experiment for 138 Xe nucleus
which is an unstable nucleus will be performed this year.

References[1]

M. Wakasugi et al.: Nucl. Instr. Meth. B317, 668 (2013).

[2]

K. Tsukada et al.: ELPH Annual Report 2014 Vol. 5, Tohoku University, 125 (2014).

[3]

K. Tsukada et al.: ELPH Annual Report 2015 Vol. 6, Tohoku University, 99 (2015).

[4]

K. Tsukada el.: Phys. Rev. Lett. 118, 262501 (2017)[5]

T. Ohnishi et al.: Nucl.Instrum.Meth. B317, 357-360 (2013).

[6]

M. Togasaki et al.: Proceedings of HIAT2015, WEPB25 (2015).

[7]

T. Suda et al.: ELPH Annual Report 2011-2013 Vol. 2, Tohoku University, 201 (2013).

[8]

T. Ohnishi et al.: Phys. Scripta, T166, 014071 (2015)[9]

B. Frois et al.: Phys. Rev. Lett. 38, 152 (1977).

[10] G. Fricke et al.: Atomic Data and Nuclear Data Tables 60, 177 (1995).
[11] J. Friedrich: A phase-shift calculation code for elastic electron scattering, communicated by
J. Friedrich.
[12] J. Heisenberg: Advances in Nuclear Physics, 12, 61 (1981)[13] J. Heisenberg and H. P. Blok: Annual Review of Nuclear and Particle Science, 33, 569 (1983)[14] M. Hua, K. Hagino: private communication.

72

ELPH Annual Report, Tohoku University (2016)(ELPH Experiment : #2836)

RI Production for the synthesis of Promethium Endohedral
Metallofullerenes by Photon Activation Method
K. Akiyama1 , S. Miyauchi1 , and H. Kikunaga2
12Department of Chemistry, Tokyo Metropolitan University, Hachioji, 192-0397 Japan.

Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826 Japan.

The production of Pm metallofullerenes were retried using chemically separated 143 Pm with higher
specific radioactivity than that of previous work. As the results of HPLC analysis, two elution peaks were
found in the dominant peak observed in the previous work and the HPLC retention time of these two
peaks were evaluated to be 61.2 min and 64.6 min, respectively, by the least square fit of data. The evaluated HPLC retention time of the first peak was found to be little later than that of La metallofullerene.

§ 1. Introduction

Endohedral metallofullerenes (EMFs) are known as a clathrate compound and are attracting in-terest of the expectation for the potential application brought from their unique physical and chemical
properties. The large number of studies about the EMFs have been reported, so far. Especially for the
EMFs of lanthanide, it has been studied for a variety of encapsulated elements from the dawn of metallofullerene research. However, only metallofullerene of promethium (Pm) has been still missing [1]. It
is well known that Pm is one of the artificial elements belonging to lanthanide elements and do not haveany naturally occurred stable isotope. The chemical property of Pm is considered to be almost same as
those of other neighboring lanthanides, actually most stable oxidation state in water is +3 similar toneighboring element of Nd. In general, Pm is produced from processing nuclear fuel and neutron irradiation of Nd in High Flux Isotope Reactor. However, 143 Pm produced by these methods is not suitable
for the metallofullerene research because of their small γ-ray emission rate and their long half life.
Recently, we reported the production of Pm metallofullerenes using 143 Pm produced by photon activation of natural samarium and their properties such as oxidation state of Pm in fullerene cage [2].
Though the oxidation state of Pm in fullerene cage and main species of Pm metallofullerenes wereclarified, there are some problems to investigate detailed information about the properties of Pm metallofullerenes. These problems is caused by the lower specific radioactivity of 143 Pm in irradiated Sm
targets. Previously, we tried to purify 143 Pm from irradiated Sm targets by cation exchange chromatography and succeeded to remove more than 90% of Sm.
Here, we report the resutls of re-investigated HPLC elution behavior of Pm metallofullerenes produced by above mentioned purified 143 Pm.
∗

Correspondance: Graduate School of Science and Engineering, Tokyo Metropolitan University,
Hachioji, 192-0397 Japan.

73§ 2. Experimental

2.1 Synthesis of Promethium Endhedral Metallofullerenes
About 1.0 g of Sm oxide were wrapped by Al foil and sealed into quarts tubes. These targets were

irradiated by 50 MeV photon at Research Center for Electron Photon Science in Tohoku University.
Irradiated Sm targets were dissolved to conc. HCl and then evaporated to dryness to make Sm and Pm
to chloride form. Chlorinated target materials were dissolved to 3 mL of 2 M HCl. Accurate 10 µL of 2
M HCl solution was added to 9.990 mL of H2 O for dilution. Pm was separated from this diluted Pm/Sm
solution by cation exchange chromatography previously reported [3].
This separated Pm was dissolved into concentrated nitric acid together with about 0.5 g of La2 O3
as a carrier. This solution was heat to dryness and then EtOH was added for dissolving resultant nitratesalts. This EtOH solution was dropped on a porous carbon rod with 10 mm diameters and 60 mm
length to adsorb the nitrate salts and then dried. This porous carbon rod was placed in an electric
tubular furnace and sintered at 700 o C under N2 gas flow. After the sintering, this rod was set into thefullerene generator as an anode for the arc discharge. The promethium EMFs were produced by the arc
discharge method [2] with DC 100 A under 60 kPa of He atmosphere. The produced soot containing
Pm EMFs was dissolved to CS2 and then filtered to remove insoluble substance. After filtration, TiCl4
was added in this solution for the pre-separation of EMFs [4]. This pre-separated EMFs solution was
evaporated to dryness and then toluene was added to dissolve fullerene species for the HPLC analysis.
2.2 HPLC Elution Behavior of Pm@C82
The EMFs toluene solution was injected into HPLC system (Pump: Hitachi L-7110, flow rate: 3.2
mL/min, UV detector: GL-Science GL-7450, λ = 340 nm) with a HPLC column of Buckyprep (Nakarai
tesque inc., size: 10 ϕmm × 250 mm). The eluate from HPLC was collected for every 20 sec withthe range from 50 to 70 min of the retention time and other fractions were collected for every 5 min
up to 100 min of the retention time. The γ-ray from each fractionated sample was determined by agermanium semiconductor detector (SEIKO EG&G, GEM25P4).

§ 3. Results and Discussion

In the previous work, we found that the main species of Pm metallofullerenes was Pm@C82 similar

to other light lanthanide metallofullerenes [2]. Figure 1 shows the HPLC chromatogram of Pm metallofullerenes investigated in this study and the HPLC chromatogram of Pm metallofullerenes obtainedin the previous work is shown in the inset. The radioactivity observed in the samples collected for 5
min plotted in this figure were averaged to be same volume as the samples collected for 20 sec. The
dominant elution peak was only observed around 60 min. This tendency is correspond to that observedin the previous work.
Figure 2 shows the detailed HPLC chromatogram around the dominant elution peak. For comparison, separately obtained chromatogram of La metallofullerenes asigned as a La@C82 was also plotted.
Although the only one elution peak was observed in the chromatogram of La metallofullerene, two elu-

74

Fig.1. HPLC elution behavior of Pm metallofullerenes. HPLC chromatogram of Pm metallofullerenes obtained in the previous work is shown in the inset.

tion peaks were observed in that of Pm metallofullerenes. To determine the exact retention time of thepeaks, least square fit was performed for the obtained data using “extreme” function as shown in thefollowing.
y = y0 + Ae(−e(−(t−tc )
(t−tc )
−
+1)
(w)
(w)
)

(1)

Here, y0 , A, tc , and w indicate the base line, the peak area, the retention time at the peak top, andthe width of the peak, respectively.
The HPLC retention time of observed elution peaks between 50 to 70 min were found to be 61.2
min for the first peak and 64.6 min for the second peak as the result of least square fitting. For the firstpeak, the retention time of the Pm metallofullerene is little later than that of the La metallofullereneand differences from that of La metallofullerene was 1.05 min. It is considered that the electronic
state of cage surface is slightly affected by the encapsulated lanthanide ion as shown in the UV/vis/NIR
absorption spectra of a series of lanthanide M@C82 , so this trend in the peak retention time is expected
to be caused by the differences of encapsulated metal ion. [5] The differences in HPLC retention time
between La@C82 and the second elution peak was 4.45 min. This value is too large to identify that thesecond peak is derived from Pm@C82 with similar electronic state of La@C82 .

Conclusion
Pm metallofullerenes were re-produced using chemically separated 143 Pm. As the results of HPLC
analysis, two elution peaks were found in the dominant peak observed in the previous work and the
HPLC retention time of these two peaks were evaluated to be 61.2 min and 64.6 min, respectively, by
the least square fit of data. The evaluated HPLC retention time of the first peak was found to be little

75

Fig.2. Detailed HPLC chromatogram around the dominant elution peak of Pm metallofullerenes. Separately obtained HPLC chromatogram of La metallofullerene is also plotted for comparison.

later than that of La metallofullerene.

Acknowledgment
We deeply thank to the facility staffs of research center for electron photon science at Tohoku University for supplying the high-quality electron beam. And also we thank to Doctor Kyo Tsukada for
helping us in the sample irradiation.

References[1]

H. Shinohara: Rep. Prog. Phys. 63 (2000) 843.

[2]

K. Akiyama et al.: ELPH Annual Rep. (2014) 135.

[3]

K. Akiyama et al.: ELPH Annual Rep. (2015) 112.

[4]

K. Akiyama et al.: J. Am. Chem. Soc. 134 (2012) 9762.

[5]

K. Akiyama et al.: J. Phys. Chem. A 104 (2000) 7224.

76

III. Status ReportELPH Annual Report, Tohoku University (2016)

77

Status of Accelerator Facilities in FY2016
Accelerator groupResearch Center for Electron Photon Science, Tohoku University, Sendai, 982-0826

The electron accelerator complex: high intensity 60 MeV linac, 90 MeV injector linac and 1.3 GeV
BST (booster-storage ring), had been regularly operated for user time in FY 2016, however some minor
troubles occurred. In this report, machine status and some improvements are presented.

§ 1. High Intensity Linac

1.1 Overview of machine operation
For the 60 MeV high intensity linac, the operating beam time reached 252 hours in FY 2016. Beamenergy with 50 and 30 MeV were used most often, and the average current was 120 µA and 80 µA,
respectively. Usually beam users bring samples to be irradiated and place them on our irradiation
system. However we also accept some users who need to use their own irradiation stand to mounttheir sample. In such case, the sample location and required beam size, etc. can be different from theregular operation, so that we performed a machine study to meet the required condition prior to the user
operation. This had taken place successfully and then such specially required operations have been also
well managed.
1.2 Installation of an AC regulated power supply in the cathode heater line
Since the recovery from the damage caused by the great earthquake in March 2011, it has become
possible to operate the BST ring and the high intensity linac independently and simultaneously. Bothmachines share a common electrical ground with the same high voltage transformer, therefore somepower supplies like gun cathode heater tend to interfere with their stable operation each other during
the simultaneous operation of both accelerators. Indeed, a drift more than 10 % has been observed in
the emission current from the cathode of the high intensity linac during the BST operation. Since theheater voltage of the cathode is particularly sensitive to the emission current from the gun, we first
introduced an AC regulated power supply for the cathode heater. There are still some power supplies tobe stabilized, so that further improvement work is underway toward the higher stability.
1.3 Replacement of insulating oil and rectifier elements in klystron modulators
Although there was no major trouble in the klystron modulators over the past decade, it had beenfound that insulating oil of some of the tanks in the modulators was considerably deteriorated withrespect to electrical insulation (Fig. 1). It turned out that many electronic components for rectifier

78
circuit in the oil tanks such as diodes, capacitors and resisters had been also damaged due to the aging
degradation (Fig. 2). We have already replaced the degraded oil and the damaged electronic components
at some oil tanks, but there are still tanks that need to replace the oil and possibly some electronic
components, so that those replacements will be carried out in the next year.

Fig.1.

Voltage transformer extracted frominsulation oil tank. It was cleaned
and refilled with new oil.

Fig.2.

Voltage rectifier units extracted frominsulation oil tank. The assembly
which some elements fails (back), andre-assembled unit (front).

1.4 Preparation of a display of operating status for beam user
Since the some beam users have to complete their own tasks, such as separation of irradiated RI
products and preparation of samples to be irradiated, during the interval of beam irradiations for theirsample, they need to manage time for the tasks. As a convenience for such users, we have been preparing
a status display of the accelerator operation. Several items: the operation status, a history of average
beam current and the irradiation logs etc., are presented in a monitor display as shown in Fig. 3. Beamposition at the target location and cooling water temperature for the target are also displayed in thesame information monitor.
1.5 Beam profiling at the dispersion section
Replacement of beam monitoring system has been continued from 2015, and optical transport forthe screen at the dispersion section had installed in this year (Fig. 4). Digital video camera, BASLER
acA1300-30gm, was used and triggered by a signal synchronized with 1 Hz beam repetition. Camera
resolution at focal point is about 110 (µm / pixel) in position. It corresponds to the energy resolution of 7

79

Fig.3.

Operation status display. Current state in the operation sequence (red). History of theaverage beam current for 3 hours (cyan). Irradiation log in chronological order (yellow).
Irradiation-position-monitor (magenta). Temperature indicator of water used for target
cooling (green).

Fig.4.

SM3 profile monitor. 9030 mm alumina
screen with its thickness 0.2 mm where
the dispersion function is 0.8 m.

Fig.5.

The intensity plot of light emitted at theSM3 screen.

keV/pixel at the screen position with the dispersion function of 0.8 m. The profile on this screen will be
used to check the beam response to the linac parameters such as the phases in accelerating structures(Fig. 5).

§ 2. 90 MeV Injector Linac for BST

At the end of FY2015, the thermionic rf gun had a problem that a discharge at the cathode cell in

the gun was frequently observed due to the deposition of carbon-like matter between the cathode and80
the cavity wall. There was no such discharge so far in the same rf gun installed in the test accelerator
t-ACTS. In order to improve the vacuum pressure in the gun cavity an additional ion pump was installedat the same time as replacing the CeB6 cathode, but the similar discharge phenomenon was nonethelessobserved again. After replacing the cathode on the end of FY2016, the injector linac has operated stably,
but the reason for the deposition is still under investigation.

§ 3. Beam transport line to BST

There are sixteen power supplies for two dipole magnets, seven quadrupoles and four steering mag-nets in the beam transport line to the BST ring. Those power supplies had been used for about twenty
years and frequently stopped abnormally during the user operation time due to an aging degradation.
In the FY2015, we had already replaced the power supplies for dipole magnets, and the remained power
supplies for the other magnets were replaced in the FY2016. The original power supplies were controlled by GPIB via Ethernet, but replaced new power supplies can be controlled by Ethernet directly.
Thus we developed control software for new power supplies, so that reliability and maintainability arealso improved significantly. An old power supply for DC septum magnet will be also replaced in nextyear.

§ 4. 1.3 GeV BST ring

In recent years, the user operation had been occasionally interrupted due to the unknown interlock

in a power supply for BST klystron. This power supply had already passed twenty years and could
be having the aging degradation as a whole. Since there is no cause related to this interlock, it was
speculated that some noise signal might be acting on the interlock circuit. During the maintenance workin summer shutdown, indeed, as it turned out that some capacitors on the control circuit were damaged
in the power supply, therefore those were exchanged. Although no further interruption caused by the
unknown interlock has occurred after the capacitor replacements, we schedule overall maintenance workof this power supply for the next year. The other improvements performed in FY2016 are presented in
the following sections.
4.1 Replacement of pumping cells in ion pumps
In the BST ring, there are 24 ion pumps and 8 NEG pumps installed to evacuate residual gas in the
beam line. All NEG pumps and some ion pumps were recently added, however, a lot of ion pumps had
passed long time of about twenty years. Some of those old ion pumps have already lost the capability toevacuate the gas, so that the vacuum pressure had exceeded over 10−5 Pa under the beam circulationof about 20 mA. In order to improve the vacuum pressure in the ring, it was required to replace the old
pumps (150 litter, diode type, Varian Inc.) to new one. Fortunately, we have kept several stocks of old ion
pumps, and also pumping cells for those old pumps can be still obtained from Agilent Technologies Inc.
Therefore we decided to replace the old pumps with the cell-replaced pumps. Partitioning the whole ring
into four areas, the pump replacement was performed for each area with step by step to minimize the81
exposure time of vacuum chamber to the air. Figure 6 shows the pictures of inside of the old ion pumpand removed pumping cells. It was found that the inside wall of the pumps had spattering vestige oftitanium but no other dirt, so that we didnt wash the inside of the pumps. The cell-replaced pumps were
baked with 250 degree for 24 hours prior to their installation into the ring. Then all ion pumps in thepartitioned area were baked with 250 degree for 24 hours again, and NEG pumps were also activated.
Figure 7 shows a trend graph of the base pressure in BST ring. On the summer shutdown in FY2015,
one NEG pump was additionally installed and some ion pumps in the injection beam line were baked.
Apparent improvement of vacuum pressure was observed at the gauge (CIG5) where the NEG pump
was additionally installed, but the effect of baking the ion pumps was not clear. Therefore it is deduced
that ion pumps cannot be revived by the baking anymore. On the summer shutdown in FY2016, twelve
ion pumps were replaced with the cell-replaced pumps. As shown in Fig. 7, the base pressure seems tohave been improved except for CIG7 and CIG8, where ion pumps were not replaced. Remained four ion
pumps will be replaced on a shutdown in FY2017.

Fig.6.

Inside of the old ion pump (left), and removed old pumping cells (right).

§ 5. Control system and Utility

As known well, Git [1] is widely used as a version control system in software development. We have

employed Git for a backup framework in our control system to improve the availability of the control
system. Distributed repositories have been allocated on a network by Git. Those repositories include ahistory of file modifications. Our system is composed of a Git server and client computers. If files or dataon the client computer are lost, those can be restored from the Git server’s repository. If the Git server
crashes, we can rebuild it from the client computer’s repository as well.
The control method of the BST steering magnets had been changed to improve a tracking accuracyof their output current since FY2014. In the new system the power supplies of steering magnets areoperated as the current amplifiers driven by an external ramping pattern, compared to the previously
used method employing pattern operation with the own pattern memory installed on the power supply

82

Fig.7.

Trend graph of the base pressure in BST ring.

itself. It turned out that the master clock frequency of the external ramping pattern for the steering
power supply is slightly higher than the required one in the actual operation, so that it caused a time
lag in the steering magnet. As a result this time lag had made it difficult to accurately correct the beam
orbit during the ramping process. Since this difference might affect the beam orbit in BST-ring, we had
fixed up the problem by tuning the master clock frequency to secure the synchronous operation.
In order to stabilize the temperature of cooling water, the rotation speed of the cooling fan havebeen already controlled by the inverter drive depending on the ambient temperature, but temperaturestability was insufficient at a specific condition like winter season. In order to improve the temperaturestability of the primary cooling water, the control system of the cooling tower fan was changed so as toalso control the number of cooling fans to be operated depending on the ambient temperature in addition
to the inverter drive. As a result of this modification, the stability was improved to one degree comparing
to the deviation of about 10 degrees for the previous condition.

References[1]

https://git-scm.com/

ELPH Annual Report, Tohoku University (2016)

83

User Support Office Report in FY2016
M. Miyabe1 and The user support office1
1

Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826, JapanThe User Support Office coordinate across the users and our facility for management of the beamtime. In 2016 financial year, we had provided the electron, photon and positron beam without apparent
problems except for Photon beamline I.

§ 1. Introduction

ELPH has three accelerators for Joint Usage/Research. Our facility could provide several beams

with following three beam lines,• 70 MeV electron linear accelerator (linac) at the first irradiation lab (For Radiochemistry)• Tagged photon beam from 1.3 GeV electron synchrotron called BST ring with 93 MeV injector at
the second irradiation lab (For Hadron Physics, Photon beamline I)• Tagged photon beam at the GeV-γ irradiation room (For Hadron Physics, Photon beamline II)

In addition, positron/electron beam line for testing detectors is located at the GeV-γ irradiation room.
The 70 MeV electron linear accelerator was utilized for the Radiochemistry experiments by photonuclear
reactions. It could produce radio active source with its high intensity. Both tagged photon beam line wasused for Hadron physics experiments. NKS2 and FOREST experiment have bean held in recent years.

§ 2. Beamtime operated

The total radiation time was 252 hours for the RI linac operation and 1178 hours for the BST

operation, and it was 1431 hours in total. The beam provided time (user beamtime) was 252 and 1198
hours for the RI linac and BST operations, and it was 1450 hours in total. Table 1 summarizes theradiation times, and user beam times in fiscal.
Many experiments for testing detectors were made by positron beam line. Positron beam was produced by bremsstrahlung photon beams from the synchrotron. Total XX shift experiments are performed
using this positron beam in this financial year.
A Next generation FOREST experiments is planned by GeV-γ group in ELPH. New bending magnet
will be installed on the downstream of FOREST detectors and it covers the most forward angle. These
new experimental setup enable the zero degree proton detection for the γd → pηn reaction at Eγ ∼ 0.9

GeV. This reaction gives the zero relative momentum between the η and n. This situation will enable todetermine the ηn scattering length. In this financial year, New Dipole Magnet (BLC) was installed in
the downstream of FOREST detectors.

84
Photon beam line I (NKS2) cannot be stably produced, because of the trouble at the radiator system
inside the synchrotron. The photon beam was recovered after temporary repairs for the radiator driving
system, but full repair will carry out in next financial year.
Two experiments were proposed, and carried out for the undergraduate students. The first one(#2857: T. Ishikawa, ELPH, Tohoku University) is for the third school for giving an opportunity using
an accelerator to young undergraduate students (Y. Sakemi) [1], which was supported by High Energy
Accelerator Research Organization (KEK) for the corporations between Tohoku University and KEK (H.
Tamura). The second one (#2855: K. Tsukada, ELPH, Tohoku University) is for the education of theundergraduate students in ELPH.
Table 1. Radiation times, and user beamtimes in financial year 2016. They are given by the sumof the times that the beam is coming to the beamline, and that the beam is provided tothe users.
RI Linuac
BST RingMonthradiation (h) user (h) radiation (h) user (h)
April
8
8
54
74
May
11
11
64
64
Jun
49
49
356
356
July
45
45
0
0
August0000September
00
00
October
27
27
104
104
November
29
29
187
187
December
19
19
65
65
January
24
24
103
103
February
19
19
71
71
March
21
21
174
174
Sum
252
252
1178
1198

§ 3. ELPH workshops and ELPH seminars

In this fiscal year, ELPH supported two ELPH workshops. The first one is hadron physics (C015: H.

Fujioka, Kyoto University), the second is SNP school 2016 (C016: S. N. Nakamura, Tohoku University).
14 ELPH seminars were held in this fiscal year. Seminars title and talker are listed below.
• Shuo Wang, Shandong University, China JinPing underground Laboratory for Nuclear Astrophysics”• Jatuporn Saisut, Plasma and beam Physics Research Facility, Chiang Mai University Research
Status of PBP - CMU - Linac Group”• C. Rangacharyulu, Univ. of Saskatchewan, ”Gray as an impractical radiation dose unit”• T. Sekihara, JAEA, ”Coupling constant vs. compositeness: a case of N(1535) in the eta N channel”• Peter von-Neuman-Cosel, Technische Universitat Darmstadt ”Nuclear Structure Studies with Virtual Photons”• K. Umemori, KEK, ”High current CW superconductive accelerator. (proposal for RI production
from cEBL)”

85• Marie-Emmanuelle Couprie, SOLEIL France COXINEL, ”Europian Laser Prasma Accelerator Projectfor X-Ray Free Electron Laser”• K. Itahashi, Riken, ”Complex structure of vacuum and precision spectroscopy of π meson atom.”• S. Hirenzaki, Nara, Women’s University ”Recent topic and Physics in mesic nuclei systems”• H. Ohnishi, Riken, ”Kaon and phi meson in nucleus”• S. Nakamura, Osaka University, ”Study for the ηn interaction with γd → ηnp reaction.”• H. Nagahiro, Nara Women’s University ”The production of eta mesic nuclei and the property ofN ∗ (1535) in nuclear medium.”• S. Sasaki, Tohoku University ”Recent result of lattice QCD at the physical point simulation for
nuclear structure.”• Y. Kino, Tohoku University ”Precision calculation for an exotic atom and molecular. - Connection
radiochemistry with nuclear physics -”References[1]

Y. Sakemi, Web site < http://cycgw1.cyric.tohoku.ac.jp/~sakemi/cyric2016.html >86

ELPH Annual Report, Tohoku University (2016)

Radiation Safety Report 2016
Radiation Safety Office

放射線安全管理室より、2016 年度（平成 28 年 4 月 ∼ 平成 29 年 3 月）の報告を以下の通り行う。

§ 1. 許認可申請
H28 年 6 月 6 日
H28 年 7 月 28 日

H28 年 9 月 26 日
H28 年 9 月 28 日

変更承認申請承認（変更の内容）1．様式第一中別紙様式イ，ハにおける使用の目的の変更
2．加速装置 1 台のエネルギー変更
3．GeV ガンマ線照射室ビームダンプの変更
4．使用核種の見直し
5．放射化物保管設備の設定
6．保管廃棄設備の変更
7．作業室グローブボックスの変更
8．下限数量以下 RI の管理区域外使用
9．インターロック動作の変更
放射線障害予防規程の変更（H28 年 10 月 21 日届出）
規制庁による立入検査（指摘事項 なし）§ 2. 個人管理

2.1 放射線業務従事者登録221 人（ 東北大 77 人 学外 128 人 研究者以外 16 人）
2.2 個人被ばく管理
1 年間の個人被ばく線量

5 mSv 以下

221 人

2.3 教育訓練
定期講習
平成 28 年 8 月 5 日

登録前教育 8 人

再教育 62 人

特別講演の内容:
高エネルギー加速器研究機構

准教授

山崎 寛仁 氏

「大強度陽子加速器施設の放射線安全管理」
不定期の講習
再教育

24 回

51 人

登録前教育（新規教育）

31 回

105 人

87

§ 3. 自主点検

年 2 回実施

平成 28 年 9 月 21 日、平成 29 年 3 月 15 日

§ 4. 放射性同位元素製造記録

2016 年度に本加速器施設で製造され，共同研究に使用された放射性同位元素は次の通りである。
核種
Be-7
C-11
F-18
Na-22
Na-24
K-42
K-43
Ca-45
Sc-46
Sc-47
V-48
Cr-51
Ni-56
Ni-57
Co-58
Cu-64

数量 (kBq)

420
10000
1000
112.01
3005
1400
17000
0.2
6000
3000
400
10020
1000
7500
20
1000

Zn-65
Ga-67
Ga-68
Br-80
Rb-84
Sr-85
Rb-86
Y-88
Nb-95
Mo-99
Cd-115
Cs-136
Cs-137
Pm-143
Ta-182
Pb-203
全 32 核種

2
1000
3000
2000
1000
310
1000
100
500
3504236.83
20
1000
6000
200
1000
70
計 3583316.04 kBq

88IV. List of Publication

ELPH Annual Report, Tohoku University (2016)

List of Publication (論文リスト) (2016)
Papers Published in Refereed Journals
Proof-of-Principle Experiment of Velocity Bunching for Ultra-short Electron Pulse Production
S. Kashiwagi, S. Nagasawa, F. Hinode, T. Muto, H. Saito, T. Abe, K. Nanbu, I. Nagasawa,
K. Takahashi, C. Tokoku, E. Kobayashi and H. Hama
Energy Procedia 89 (2016) 346–352.
High voltage threshold for stable operation in a dc electron gun
M. Yamamoto and N. Nishimori
Applied Physics Letters 109 (2016) 014103.
Enhanced diffraction of MeV γ-rays by mosaic crystals
S. Matsuba, T. Hayakawa, T. Shizuma, N. Nishimori, R. Nagai, M. Sawamura, C.T. Angell,
M. Fujiwara, R. Hajima
Japanese Journal of Applied Physics 55 (2016) 112402.
Prospoects for Electron Scattering on Unstable, Exotic Nuclei (Review paper)
T. Suda and H. Simon
Progress of Particle and Nuclear Physics 96 (2017) 1–31.
極低運動量領域での電子・陽子弾性散乱による陽子荷電半径の精密決定
須田利美, 塚田暁
原子核研究 61 (2017) 87–98.

Spectroscopy of the neutron-rich hypernucleus 7Λ He from electron scattering
T. Gogami, C. Chen, D. Kawama, P. Achenbach, A. Ahmidouch, I. Albayrak, D. Androic,
A. Asaturyan, R. Asaturyan, O. Ates, P. Baturin, R. Badui, W. Boeglin, J. Bono, E. Brash,
P. Carter, A. Chiba, E. Christy, S. Danagoulian, R. De Leo, D. Doi, M. Elaasar, R. Ent,
Y. Fujii, M. Fujita, M. Furic, M. Gabrielyan, L. Gan, F. Garibaldi, D. Gaskell, A. Gasparian,
Y. Han, O. Hashimoto, T. Horn, B. Hu, Ed. V. Hungerford, M. Jones, H. Kanda, M. Kaneta,
S. Kato, M. Kawai, H. Khanal, M. Kohl, A. Liyanage, W. Luo, K. Maeda, A. Margaryan,
P. Markowitz, T. Maruta, A. Matsumura, V. Maxwell, A. Mkrtchyan, H. Mkrtchyan, S. Nagao,
S.N. Nakamura, A. Narayan, C. Neville, G. Niculescu, M.I. Niculescu, A. Nunez, Nuruzzaman, Y. Okayasu, T. Petkovic, J. Pochodzalla, X. Qiu, J. Reinhold, V.M. Rodriguez, C. Samanta,
B. Sawatzky, T. Seva, A. Shichijo, V. Tadevosyan, L. Tang,, N. Taniya, K. Tsukada, M. Veilleux,
W. Vulcan, F.R. Wesselmann, S.A. Wood, T. Yamamoto, L. Ya, Z. Ye, K. Yokota, L. Yuan,
S. Zhamkochyan, and L. Zhu
Phys. Rev. C 94 (2016) 021302.
Ground-state binding energy of 4Λ H from high-resolution decay-pion spectroscopy
F. Schulz, P. Achenbach, S. Aulenbacher, J. Beričič, S. Bleser, R. Böhm, D. Bosnard, L. Correa,

89

90
M.O. Distler, A. Esser, H. Fonvieille, I. Friščič, Y. Fujii, M. Fujita, T. Gogami, H. Kanda,
M. Kaneta, S. Kegel, Y. Kohl, W. Kusaka, A. Margaryan, H. Merkel, M. Mihovilovič, U. Müller,
S. Nagao, S.N. Nakamura, J. Pochodzalla, A. Sanchez Lorente, B.S. Schlimme, M. Schoth,
C. Sfienti, S. Širca, M. Steinen, c, Y. Takahashi, L. Tang, M. Thiel, K. Tsukada, A. Tyukin,
A. WeberNucl. Phys. A954 (2016) 149–160.
Structure near the K− + p + p threshold in the in-flight 3 He(K − ,Λp)n reaction
Y. Sada, S. Ajimura, M. Bazzi, G. Beer, H. Bhang, M. Bragadireanu, P. Buehler, L. Busso,
M. Cargnelli, S. Choi, C. Curceanu, S. Enomoto, D. Faso, H. Fujioka, Y. Fujiwara, T. Fukuda,
C. Guaraldo, T. Hashimoto, R.S. Hayano, T. Hiraiwa, M. Iio, M. Iliescu, K. Inoue, Y. Ishiguro,
T. Ishikawa, S. Ishimoto, T. Ishiwatari, K. Itahashi, M. Iwai, M. Iwasaki, Y. Kato, S. Kawasaki,
P. Kienle, H. Kou, Y. Ma, J. Marton, Y. Matsuda, Y. Mizoi, O. Morra, T. Nagae, H. Noumi,
H. Ohnishi, S. Okada, H. Outa, K. Piscicchia, A. Romero Vidal, A. Sakaguchi, F. Sakuma,
M. Sato, A. Scordo, M. Sekimoto, H. Shi, D. Sirghi, F. Sirghi, K. Suzuki, S. Suzuki, T. Suzuki,
K. Tanida, H. Tatsuno, M. Tokuda, D. Tomono, A. Toyoda, K. Tsukada, O. Vazquez Doce,E. Widmann, B.K. Wuenschek, T. Yamaga, T. Yamazaki, H. Yim, Q. Zhang, J. Zmeskal
Prog. Theor. Exp. Phys. 2017, 051D01.
Studies of high density baryon matter with high intensity heavy-ion beams at J-PARC
H. Sako, H. Harada, T. Sakaguchi, T. Chujo, S. Esumi, T. Gunji, S. Hasegawa, S.H. Hwang,
Y. Ichikawa, K. Imai, K. Itakura, M. Kaneta, B.C. Kim, M. Kinsho, M. Kitazawa, Y. Liu,
H. Masui, S. Nagamiya, K. Nishio, M. Okamura, K. Oyama, K. Ozawa, P.K. Saha, A. Sakaguchi, S. Sato, K. Shigaki, H. Sugimura, K. Tanida, J. Tamura, H. Tamura, Y. Nara, T.R. Saito(J-PARC Heavy-Ion Collaboration)
Nucl. Phys. A956 (2016) 850–853.
Limonene enhances the cAMP response element (CRE)-dependent transcriptional activity activated via
adenosine A2A receptor in a neural-crest derived cell line, PC-12
J. Takito, M. Ota, C. Oba, H. Fujiwara, K. Murata, K. Yamaguchi, N. Uozumi, M. Nakamura,
H. Inomata and Y. Ohizumi
Planta Medica International Open 2016, 3:e60–e62.
The topogenic function of S4 promotes membrane insertion of the voltage-sensor domain in the KvAP
channelE. Mishima, Y. Sato, K. Nanatani, N. Hoshi, J-K. Lee, N. Schiller, G. von Heijne, M. Sakaguchi, and N. Uozumi
Biochem. J. 473 (2016) 4361–4372.
Ion channels in plant bioenergetic organelles chloroplast and mitochondria: from molecular identification to function
L. Carraretto, E. Teardo, V. Checchetto, G. Finazzi, N. Uozumi, and I. Szabo
Mol. Plant 9 (2016) 371–395.

91
Involvement of potassium transport systems in the response of Synechocystis PCC 6803 cyanobactria toexternal pH change, high-intensity light sress and heavy metal stress
V. Checchetto, A. Sgalla, Y. Sato, E. Bergantine, I. Szabo and N. Uozumi
Plant Cell Physiol. 57 (2016) 862–877.
Nerve growth factor enhances the CRE-dependent transcriptional activity activated by nobiletin in PC12 cells
J. Takito, J. Kimura, K. Kajima, N. Uozumi, M. Watanabe, A. Yokosuka, Y. Mimaki, M. Nakamura, and Y. Ohizumi
Can. J. Physiol. Pharm. 94 (2016) 728–733.
Calculation of resonance states of positronic lithium atom
T. Yamashita, Y. Kino
Eur. Phys. J. D 70 (2016) 190–198.
Analysis of plasma protein concentrations and enzyme activities in cattle within the ex-evacuation zoneof the Fukushima Daiichi Nuclear Plant accident
Y. Urushihara, K. Kawasumi, S. Endo, K. Tanaka, Y. Hirakawa, G. Hayashi, T. Sekine,
Y. Kino, Y. Kuwahara, M. Suzuki, M. Fukumoto, H. Yamashiro, Y. Abe, T. Fukuda, H. Shinoda, E. Isogai, T. Arai, M. Fukumoto
PLoS ONE 11 (2016) e0155069.
90

Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi

Nuclear Power Plant accident
K. Koarai, Y. Kino, A. Takahashi, T. Suzuki, Y. Shimizu, M. Chiba, K. Osaka, K. Sasaki,
T. Fukuda, E. Isogai, H. Yamashiro, T. Oka, T. Sekine, M. Fukumoto, H. Shinoda
Scientific Reports, 6 (2016) 24077.
Software development for estimating the concentration of radioactive cesium in the skeletal muscles ofcattle from blood samples
T. Fukuda, M. Hiji, Y. Kino, Y. Abe, H. Amashiro, J. Kabayashi, Y. Shimizu, A. Takahashi,
T. Suzuki, M. Chiba, K. Inoue, Y. Kuwahara, M. Morimoto, M. Katayama, K. Donai, H. Shinoda, T. Sekine, M. Fukumoto, E. Isogai
Animal Science Journal, 87 (2016), 842–847.
陽電子が拓く物質の科学 第 2 回 陽電子・原子間相互作用と陽電子原子
木野康志, 山下琢磨
しょうとつ 13 (2016) 37-46.
相対論効果を含む陽電子アルカリ原子の弱束縛状態の高精度計算
山下琢磨, 木野康志
陽電子科学 6 (2016) 35-44.

Evolution of fusion hindrance for asymmetric systems at deep sub-barrier energies
A. Shrivastava, K. Mahata, S.K. Pandit, V. Nanal, T. Ichikawa, K. Hagino, A. Navin, C.S. Palshetkar, V.V. Parkar, K. Ramachandran, P.C. Rout, Abhinav Kumar, A. Chatterjee, and S. Kailas

92
Phys. Lett. B755 (2016) 332–336.
Low-energy hypernuclear spectra with microscopic particle-rotor model with relativistic point coupling
hyperon-nucleon interaction
H. Mei, K. Hagino, J.M. Yao, and T. Motoba
Phys. Rev. C 93 (2016) 044307.
Investigating mult-channel quantum tunneling in heavy-ion fusion reactions with Bayesian spectral
deconvolution
K. Hagino
Phys. Rev. C 93 (2016) 061601(R).
Anharmonicity of multi-octupole-phonon excitations in 208 Pb: analysis with multi-reference covariant
density functional theory and subbarrier fusion of 16 O+208 Pb
J.M. Yao and K. Hagino
Phys. Rev. C 94 (2016) 011303(R).
New concept for pairing anti-halo effect as a localized wave packet of quasi-particle
K. Hagino and H. Sagawa
Phys. Rev. C 95 (2017) 024304.
The FOREST detector for meson photoproduction experiments at ELPH
T. Ishikawa, H. Fujimura, H. Fukasawa, R. Hashimoto, T. Ishida, S. Kaida, J. Kasagi, A. Kawano,
S. Kuwasaki, K. Maeda, F. Miyahara, K. Mochizuki, T. Nakabayashi, A. Nakamura, K. Nawa,
S. Ogushi, Y. Okada, K. Okamura, Y. Onodera, Y. Saito, Y. Sakamoto, M. Sato, H. Shimizu,
H. Sugai, K. Suzuki, S. Takahashi, Y. Tsuchikawa, H. Yamazaki, H. Yonemura
Nucl. Instr. Meth. A832 (2016) 108–143.
Testing a prototype BGO calorimeter with 100–800 MeV positron beams
T. Ishikawa, H. Fujimura, D.N. Grigoriev, R. Hashimoto, S. Kaida, R. Kitazawa, G.N. Kuznetsov,
A. Nakamura, H. Shimizu, K. Suzuki, S. Takahashi, Y. Tsuchikawa, Ya.V. Vasiliev, H. Yamazaki
Nucl. Instr. Meth. A837 (2016) 109–122.
An event mixing technique for Bose-Einstein correlations of two pions in photoproduction around 1 GeV
Q. He, H. Fujimura, H. Fukasawa, R. Hashimoto, Y. Honda, T. Ishikawa, T. Iwata, S. Kaida,
J. Kasagi, A. Kawano, S. Kuwasaki, K. Maeda, S. Masumoto, M. Miyabe, F. Miyahara, K. Mochizuki,
N. Muramatsu, A. Nakamura, K. Nawa, S. Ogushi, Y. Okada, Y. Onodera, K. Ozawa, Y. Sakamoto,
M. Sato, H. Shimizu, H. Sugai, K. Suzuki, Y. Tajima, S. Takahashi, Y. Taniguchi, Y. Tsuchikawa,
H. Yamazaki, R. Yamazaki, H.Y. Yoshida
Chinese Phys. C40 (2016) 114002.
Interference Effect between ϕ and Λ(1520) Production Channels in the γp → K + K − p Reaction near
ThresholdS.Y. Ryu, J.K. Ahn, T. Nakano, D.S. Ahn, S. Ajimura, H. Akimune, Y. Asano, W.C. Chang,
J.Y. Chen, S. Date, H. Ejiri, H. Fujimura, M. Fujiwara, S. Fukui, S. Hasegawa, K. Hicks,

93
K. Horie, T. Hotta, S.H. Hwang, K. Imai, T. Ishikawa, T. Iwata, Y. Kato, H. Kawai, K. Kino,
H. Kohri, Y. Kon, N. Kumagai, P.J. Lin, Y. Maeda, S. Makino, T. Matsuda, N. Matsuoka,
T. Mibe, M. Miyabe, M. Miyachi, Y. Morino, N. Muramatsu, R. Murayama, Y. Nakatsugawa,
S.I. Nam, M. Niiyama, M. Nomachi, Y. Ohashi, H. Ohkuma, T. Ohta, T. Ooba, D.S. Oshuev,
J.D. Parker, C. Rangacharyulu, A. Sakaguchi, T. Sawada, P.M. Shagin, Y. Shiino, H. Shimizu,
E.A. Strokovsky, Y. Sugaya, M. Sumihama, A.O. Tokiyasu, Y. Toi, H. Toyokawa, T. Tsunemi,
M. Uchida, M. Ungaro, A. Wakai, C.W. Wang, S.C. Wang, K. Yonehara, T. Yorita, M. Yoshimura,
M. Yosoi, R.G.T. Zegers (LEPS Collaboration)
Phys. Rev. Lett. 116 (2016) 232001.
A study of event mixing for two-pion Bose-Einstein correlations in the γp → π 0 π 0 p reaction

Q. He, J. Ai, T. Ishikawa, T. Li, L. Ma, J. Ma, M. Miyabe, N. Muramatsu, H. Shimizu,
Y. Tsuchikawa, Y. Xiang, H. Yamazaki, Y. Zhang
Prog. Theor. Exp. Phys. 2017, 033D02.

Virtual Institute for Quark Nuclear Physics at SPring-8/LEPS2
H. Shimizu and N. Muramatsu
Nuclear Physics News 27:1 (2017) 19–22.
Near threshold angular distributions for the 2 H(γ,Λ)X reaction
B. Beckford, P. Bydzovsky, A. Chiba, D. Doi, T. Fujii, Y. Fujii, K. Futatsukawa, T. Gogami,
O. Hashimoto, Y.C. Han, K. Hirose, R. Honda, K. Hosomi, T. Ishikawa, H. Kanda, M. Kaneta,
Y. Kaneko, S. Kato, D. Kawama, C. Kimura, S. Kiyokawa, T. Koike, K. Maeda, K. Makabe,
M. Matsubara, K. Miwa, S. Nagao, S.N. Nakamura, A. Okuyama, K. Shirotori, K. Sugihara,
K. Suzuki, T. Tamae, H. Tamura, K. Tsukada, F. Yamamoto, T.O. Yamamoto, F. Yonemoto,and H. Yamazaki
Prog. Theor. Exp. Phys. 2016, 063D01.
High resolution spectroscopic study of 10
Λ Be
T. Gogami, C. Chen, D. Kawama, P. Achenbach, A. Ahmidouch, I. Albayrak, D. Androic,
A. Asaturyan, R. Asaturyan, O. Ates, P. Baturin, R. Badui, W. Boeglin, J. Bono, E. Brash,
P. Carter, A. Chiba, E. Christy, S. Danagoulian, R. De Leo, D. Doi, M. Elaasar, R. Ent,
Y. Fujii, M. Fujita, M. Furic, M. Gabrielyan, L. Gan, F. Garibaldi, D. Gaskell, A. Gasparian, Y. Han, O. Hashimoto, T. Horn, B. Hu, E.V. Hungerford, M. Jones, H. Kanda, M. Kaneta,
S. Kato, M. Kawai, H. Khanal, M. Kohl, A. Liyanage, W. Luo, K. Maeda, A. Margaryan,
P. Markowitz, T. Maruta, A. Matsumura, V. Maxwell, A. Mkrtchyan, H. Mkrtchyan, S. Nagao,
S.N. Nakamura, A. Narayan, C. Neville, G. Niculescu, M.I. Niculescu, A. Nunez, Nuruzzaman, Y. Okayasu, T. Petkovic, J. Pochodzalla, X. Qiu, J. Reinhold, V.M. Rodriguez, C. Samanta,
B. Sawatzky, T. Seva, A. Shichijo, V. Tadevosyan, L. Tang, N. Taniya, K. Tsukada, M. Veilleux,
W. Vulcan, F.R. Wesselmann, S.A. Wood, T. Yamamoto, L. Ya, Z. Ye, K. Yokota, L. Yuan,
S. Zhamkochyan, and L. Zhu (HKS(JLab E05-5) Collaboration)
Phys. Rev. C 93, (2016), 034314.

94High precision momentum calibration of the magnetic spectrometers at MAMI for hypernuclear binding
energy determination
A. Margaryan, J.R.M. Annand, P. Achenbach, R. Ajvazyan, H. Elbakyan, R. Montgomery,
S.N. Nakamura, J. Pochodzalla, F. Schulz, Y. Toyama, S. Zhamkochyan
Nucl. Instr. Meth. A846 (2017) 98–105.
ストレンジネス核物理中村哲
原子核研究 60 supp.1 (2016 夏の学校特集号) 17-21.

Transverse energy production and charged-particle multiplicity at midrapidity in various systems from√sN N = 7.7 to 200 GeV
A. Adare, et al. (PHENIX Collaboration)
Phys. Rev. C 93 (2016) 024901.
Scaling properties of fractional momentum loss of high-pT hadrons in nucleus-nucleus collisions at√
sN N from 4 GeV to 6 TeV
A. Adare, et al. (PHENIX Collaboration)
Phys. Rev. C 93 (2016) 024911.
凝縮系核反応研究の現状と今後 ∼ 革新的放射性元素変換技術の開発に向けて ∼岩村康弘

電気評論 2016 年 7 月号 42-46.

Screening energy of the D+D reaction in an electron plasma deduced from cooperating colliding reaction
J. Kasagi and Y. Honda
J. Condensed Matter Nucl. Sci. 19 (2016) 127–134.
Astrophysical S factor for the 6 Li(d,α)4 He and 6 Li(d,p0/p1)7 Li reactions and their astrophysical implications
K. Fang, J. Zou, H. He, Q. Wang, J. Zhao, T. Wang, and J. Kasagi
Phys. Rev. C 94 (2016) 054602.

Papers Published in International Conference Proceedings
Status of the 1.3 GeV Booster Synchrotron for Generating High Energy Gamma Rays at Tohoku University
F. Hinode, H. Hama, S. Kashiwagi, T. Muto, I. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi, C. Tokoku
Proc. of IPAC2016 (2016) 701–703.
Generation of Coherent Undulator Radiation using Extremely Short Electron Bunch at t-ACTS, Tohoku
University
S. Kashiwagi, T. Abe, H. Hama, F. Hinode, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, Y. Shibasaki,
K. Takahashi, C. Tokoku
Proc. of IPAC2016 (2016) 1760–1762.

95
Production of Ultra-short Electron Pulse and Observation of Coherent Transition Radiation at t-ACTS,
Tohoku University
T. Abe, H. Hama, F. Hinode, S. Kashiwagi, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, Y. Shibasaki,
K. Takahashi, C. Tokoku
Proc. of IPAC2016 (2016) 1763–1765.
Profile Measurements of Bremsstrahlung Gamma-Rays from Tungsten Plates for Radioactive Isotope
Production via Photonuclear Reaction using a 60 MeV Electron Linac
K. Takahashi, H. Hama, F. Hinode, S. Kashiwagi, H. Kikunaga, T. Muto, I. Nagasawa, K. Nanbu,
Y. Shibasaki, T. Suda, C. Tokoku, K. Tsukada
Proc. of IPAC2016 (2016) 1766–1768.
Development Status of Linear Focal Cherenkov Ring Camera
K. Nanbu, T. Abe, H. Hama, F. Hinode, S. Kashiwagi, T. Muto, I. Nagasawa, H. Saito, K. Takahashi, C. Tokoku
Proc. of IPAC2016 (2016) 152–154.
Generation of Coherent Undulator Radiation at ELPH, Tohoku University
S. Kashiwagi, T. Abe, H. Hama, F. Hinode, T. Muto, K. Nanbu, I. Nagasawa, H. Saito, Y. Saito,
Y. Shibasaki, K. Takahashi
Proc. of LINAC2016 (2016) 316–318.
ELECTRON DRIVEN ILC POSITRON SOURCE WITH A LOW GRADIENT CAPTURE LINAC
M. Kuriki, T. Kakita, T. Takahashi, K. Negishi, T. Okugi, T. Omori, M. Satoh, Y. Seimiya,J. Urakawa, K. Yokoya, S. Kashiwagi
Proc. of LINAC2016 (2016) 430–433.
SIX-DIMENSIONAL PHASE-SPACE ROTATION AND ITS APPLICATIONS
M. Kuriki, K. Negishi, H. Hayano, R. Kato, K. Ohmi, M. Satoh, Y.Seimiya, J. Urakawa and
S. Kashiwagi
Proc. of IPAC2016 (2016) 1754–1756.
DC Photoemission Gun Upgrade at the Compact ERL
N. Nishimori, R. Hajima, R. Nagai, M. Mori, M. Yamamoto, Y. Honda, T. Miyajima, T. Uchiyama
Proc. of IPAC2016, Busan, Korea, THPOW008, 3944–3946.
Recent Developments and Operational Status of the Compact ERL at KEK
T. Obina, M. Adachi, S. Adachi, T. Akagi, M. Akemoto, D.A. Arakawa, S. Araki, S. Asaoka,
M. Egi, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda,
Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X.J. Jin, E. Kako,
Y. Kamiya, H. Katagiri, R. Kato, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondo, T. Konomi,
A. Kosuge, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura,
T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, S. Sasaki, K. Satoh, Y. Seimiya, T. Shidara, M. Shimada,96
K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki,
T. Takenaka, O. Tanaka, Y. Tanimoto, N. Terunuma, M. Tobiyama, K. Tsuchiya, T. Uchiyama,
A. Ueda, K. Umemori, J. Urakawa, K. Watanabe, M. Yamamoto, N. Yamamoto, Y. Yamamoto,Y. Yano, M. Yoshida, R. Hajima, M. Mori, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma,
M. Kuriki
Proc. of IPAC2016, Busan, Korea, THPOW036, 1835–1838.
Spectroscopic Experiment of Λ(1405) via the In-flight d(K − ,n) Reaction at J-PARC K1.8BR
S. Kawasaki, S. Ajimura, G. Beer, H. Bhang, M. Bragadireanu, P. Buehler, L. Busso,, M. Cargnelli,
S. Choi, C. Curceanu, S. Enomoto, D. Faso,, H. Fujioka, Y. Fujiwara, T. Fukuda, C. Guaraldo,
T. Hashimoto, R. Hayano, T. Hiraiwa, M. Iio, M. Iliescu, K. Inoue, T. Ishikawa, S. Ishimoto,K. Itahashi, M. Iwai, M. Iwasaki,, P. Kienlep, H. Kou, Y. Ma, J. Marton, Y. Matsuda, H. Mizoi,
O. Morra, T. Nagae, H. Noumi, H. Ohnishi,, S. Okada, H. Outa, D. Pietreanu, Y. Sada, A. Sakaguchi, F. Sakuma, M. Sato, M. Sekimoto, H. Shi, K. Shirotori, D. Sirghi,, F. Sirghi, K. Suzuki,
S. Suzuki, T. Suzuki, K. Tanida, H. Tatsuno, M. Tokuda, M. Tomono, A. Toyoda, K. Tsukada,
E. Widmann, T. Yamaga, K. Yoshida, T. Yamazaki,, H. Yim, Q. Zhang, and J. Zmeskal
JPS Conf.Proc. 13 (2017) 020018.
Study of the elementary (K − ,n) reactions to search for the K− NN bound state via the 3 He(K − ,n) reaction at J-PARC
T. Yamaga, S. Ajimura, G. Beer, C. Berucci, H. Bhang, M. Bragadireanu, P. Buehler, L. Busso,
M. Cargnelli, S. Choi, C. Curceanu, S. Enomoto, D. Faso, H. Fujioka, Y. Fujiwara, T. Fukuda,
C. Guaraldo, T. Hashimoto, R.S. Hayano, T. Hiraiwa, M. Iio, M. Iliescu, K. Inoue, Y. Ishiguro,
T. Ishikawa, S. Ishimoto, T. Ishiwatari, K. Itahashi, M. Iwai, M. Iwasaki,, K. Kanno, K. Kato,
Y. Kato, S. Kawasaki1, P. Kienle, T. Kim, H. Kou, Y. Ma, J. Marton, Y. Matsuda, Y. Mizoi,
O. Morra, T. Nagae, H. Noumi, H. Ohnishi, S. Okada, H. Outa, K. Piscicchia, A. Romero
Vidal, Y. Sada, A. Sakaguchi1, F. Sakuma, M. Sato, A. Scordo, M. Sekimoto, H. Shi, K. Shirotori, D. Sirghi,, F. Sirghi,, K. Suzuki, S. Suzuki, T. Suzuki, K. Tanida, H. Tatsuno, M. Tokuda,
D. Tomono, A. Toyoda, K. Tsukada, O. Vazquez Doce, E. Widmann, B.K. Wuenschek, T. Yamazaki, H. Yim, Q. Zhang, and J. Zmeskal
AIP Conf. Proc. 1735 (2016) 040007.
Study of the K− -Nucleus Interaction by Using the 12 C(K − ,p) Reaction at J-PARC
Y. Ichikawa, J.K. Ahn, Y. Akazawa, K. Aoki, E. Botta, H. Ekawa, P. Evtoukhovitch, A. Feliciello, M. Fujita, T. Gogami, S. Hasegawa, T. Hasegawa, S. Hayakawa, T. Hayakawa, R. Honda,
K. Hosomi, K. Imai, W.S. Jung, S. Kanatsuki, S.H. Kim, S. Kinbara, K. Kobayashi, J.Y. Lee,
S. Marcello, K. Miwa, T.J. Moon, T. Nagae, Y. Nakada, M. Nakagawa, T. Nanamura, M. Naruki,
A. Sakaguchi, H. Sako, S. Sato, Y. Sasaki, K. Shirotori, H. Sugimura, T. Takahashi, H. Tamura,
K. Tanida, Z. Tsamalaidze, M. Ukai, and T.O. Yamamoto
JPS Conf. Proc. 13 (2017) 020007.
Present status of coupled-channels calculations for heavy-ion subbarrier fusion reactions

97
K. Hagino and J.M. Yao
EPJ Web of Conferences 117 (2016) 08003.
Recent developments in heavy-ion fusion reactions around the Coulomb barrier
K. Hagino, N. Rowley, and J.M. Yao
EPJ Web of Conferences 122 (2016) 07002.
Fission life-time calculation using a complex absorbing potential
G. Scamps and K. Hagino
EPJ Web of Conferences 122 (2016) 01004.
Three-body model for nuclei near and beyond drip line
H. Sagawa and K. Hagino
Acta Phys. Polon. Supp. 10 (2017) 211–224.
The basic performance of the TOF-RPC for the BGOegg experimentN. Tomida, N. Tran, M. Niiyama, H. Ohnishi and N. Muramatsu
Proc. of RPC2016; J. of Instr. 11 (2016) C11037.
ηn Scattering Length from the γd → pηn Reaction at Eγ ∼ 0.9 GeV

T. Ishikawa, H. Fujioka, Y. Honda, T. Hotta, Y. Inoue, K. Itahashi, H. Kanda, H. Kawai,
K. Maeda, M. Miyabe, S. Miyata, Y. Matsumura, N. Muramatsu, H. Ohnishi, K. Ozawa,
M. Sasagawa, H. Shimizu, K. Shiraishi, M. Tabata, A.O. Tokiyasu, and Y. Tsuchikawa
Proc. of 14th International Conference on Meson-Nucleon Physics and the Structure of the
Nucleon (MENU2016), JPS Conf. Proc. 13 (2017) 020031.

Simultaneous Photoproduction Of Neutral And Charged Pions On The Deuteron At ELPH
T. Ishikawa, A. Nakamura, H. Fujimura, R. Hashimoto, Q. He, S. Kaida, M. Miyabe, N. Muramatsu, H. Shimizu, K. Suzuki, Y. Tschikawa, H. Yamazaki, R. Yamazaki, S. Masumoto,Y. Obara, K. Maeda, K. Ozawa
Proc. of the 26th International Nuclear Physics Conference (INPC), PoS(INPC2016)267.
ηn scattering length from γd → pηn at Eγ ∼ 0.93 GeV

T. Ishikawa, H. Fujioka, Y. Honda, T. Hotta, Y. Inoue, K. Itahashi, H. Kanda, H. Kawai,
K. Maeda, M. Miyabe, S. Miyata, Y. Matsumura, N. Muramatsu, H. Ohnishi, K. Ozawa,
M. Sasagawa, H. Shimizu, K. Shiraishi, M. Tabata, A.O. Tokiyasu, Y. Tsuchikawa
Proc. of the international symposium on Neutron Star Matter 2016 (NSMAT2016).

Application of an X-Ray Flat Panel Sensor to a GeV Region Gamma-Ray Beam Profile Monitor
H. Kanda, K. Honda, T. Ishikawa, M. Kaneta, K. Maeda, M. Miyabe, Y. Muroi, S.N. Nakamura, A. Ninomiya, Y. Obara, K. Ozawa, K. Ozeki, T. Sasaki, H. Shimizu, A.O. Tokiyasu
Conference Record of IEEE Nuclear Science Symposuim & Medical Imaging Conference 2016.
Development of a high-intensity photon-beam profile monitor
T. Ishikawa, H. Fujimura, R. Hashimoto, Y. Honda, T. Ishida, H. Kanda, S. Kido, Y. Matsumura, M. Miyabe, I. Nagasawa, K. Nanbu, H. Shimizu, K. Suzuki, K. Takahashi, A.O. Tokiyasu,
Y. Tsuchikawa, H. Yamazaki

98
Conference Record of IEEE Nuclear Science Symposuim & Medical Imaging Conference 2016.
Study of the d(γ,K + )ΣπN Reaction at LEPS
A.O. Tokiyasu
JPS Conf. Proc. 13 (2017) 020017.
Near Threshold K0 Λ Photoproduciton on the Neutron Studied with an Electromagnetic Calorimeter
FOREST
Y. Tsuchikawa, H. Fujimura, H. Fukasawa, R. Hashimoto, Q. He, Y. Honda, T. Ishikawa,T. Iwata, S. Kaida, J. Kasagi, A. Kawano, S. Kuwasaki, K. Maeda, S. Masumoto, M. Miyabe,
F. Miyahara, K. Mochizuki, N. Muramatsu, A. Nakamura, K. Nawa, S. Ogushi, Y. Okada,
Y. Onodera, K. Ozawa, Y. Sakamoto, M. Sato, H. Shimizu, H. Sugai, K. Suzuki, Y. Tajima,
S. Takahashi, Y. Taniguchi, H. Yamazaki, R. Yamazaki, and H. Y. Yoshida
JPS Conf. Proc. 10 (2016) 032010.
Meson Photoproduction Experiments at ELPH, Tohoku University
T. Ishikawa, H. Fujimura, H. Fukasawa, R. Hashimoto, Q. He, Y. Honda, T. Iwata, S. Kaida,
J. Kasagi, A. Kawano, S. Kuwasaki, K. Maeda, S. Masumoto, M. Miyabe, F. Miyahara, K. Mochizuki,
N. Muramatsu, A. Nakamura, K. Nawa, S. Ogushi, Y. Okada, Y. Onodera, K. Ozawa, Y. Sakamoto,
M. Sato, H. Shimizu, H. Sugai, K. Suzuki, Y. Tajima, S. Takahashi, Y. Taniguchi, Y. Tsuchikawa,
H. Yamazaki, R. Yamazaki, and H.Y. Yoshida (the FOREST Collaboration)
JPS Conf. Proc. 10 (2016) 031001.
Double neutral pion photoproduction off the proton with FOREST at ELPH
Q. He, H. Fujimura, H. Fukasawa, R. Hashimoto, Y. Honda, T. Ishikawa, T. Iwata, S. Kaida,
J. Kasagi, A. Kawano, S. Kuwasaki, K. Maeda, S. Masumoto, M. Miyabe, F. Miyahara, K. Mochizuki,
N. Muramatsu, A. Nakamura, K. Nawa, S. Ogushi, Y. Okada, Y. Onodera, K. Ozawa, Y. Sakamoto,
M. Sato, H. Shimizu, H. Sugai, K. Suzuki, Y. Tajima, S. Takahashi, Y. Taniguchi, Y. Tsuchikawa,
H. Yamazaki, R. Yamazaki and H.Y. Yoshida
EPJ Web Conf. 109 (2016) 04004.
Experimental investigations of the hypernucleus 4Λ H
P. Achenbach, F. Schulz, S. Aulenbacher, J. Beričič, S. Blese, R. Böhm, D. Bosnar, L. Correa,
M.O. Distler, A. Esser, H. Fonvieille, I. Friščič, Y. Fujii, M. Fujita, T. Gogami, H. Kanda,
M. Kaneta, S. Kegel, Y. Kohl, W. Kusaka, A. Margaryan, H. Merkel, M. Mihovilovič, U. Müller,
S. Nagao, S.N. Nakamura, J. Pochodzalla, A. Sanchez Lorente, B.S. Schlimme, M. Schoth,
C. Sfienti, S. Širca, M. Steinen, Y. Takahashi, L. Tang, M. Thiel, K. Tsukada, A. Tyukin and
A. Weber (A1 Collaboration)
Proc. of FB21; EPJ Web of Conferences 113 (2016) 07001.
The Launch of a New Plan on Condensed Matter Nuclear Science at Tohoku University
Y. Iwamura, J. Kasagi, H. Kikunaga, H. Yoshino, T. Itoh, M. Hattori and T. Mizuno
J. Condensed Matter Nucl. Sci. 19 (2016) 119–126.
Anomalous Excess Heat Generated by the Interaction between Nano-structured Pd/Ni surface and D2

99
gas
T. Itoh, Y. Iwamura, J. Kasagi, H. Shishido
Proc. of The 20th International Conference on Condensed Matter Nuclear Science (2017)
179–190.

Invited Talk and Oral Presentations at International Conferences
SLiT-J, a high brilliant compact 3 GeV light source project in Japan (Oral presentation)
H. HamaCanadian Light Source Laboratory, Saskatoon, Saskatchewan, Canada, Mar. 22, 2016.
Variable polarized narrowband THz source based on undulator super-radiant (Invited oral presentation)
H. Hama
Energy Materials Nanotechnology (EMN) Meeting on Teraherts, Donostia, Spain, May 16,
2016.
Expected performance of SLiT-J – at a glance – (Oral presentation)
H. HamaInternational Review Committee Meeting of the SLiT-J project, Sendai, Japan, June 21, 2016.
Status of SLiT-J – a high brilliant compact 3 GeV light source project in Japan – (Oral presentation)
H. Hama
Low Emittance Rings Workshop 2016, Synchrotron SOLEIL, Gif-sur-Yvette Cedex, France,
Oct. 26, 2016.
Demonstration of coherent radiation generation up to 3 THz from femtosecond electron pulses (Oralpresentation)
H. Hama
13th Eco-Energy and Materials Science and Engineering Symposium (EMSES2016), Udorn
Thani, Thailand, Dec. 2, 2016.
Latest beam physics activities at t-ACTS, Tohoku University (Oral presentation)
H. Hama
Plasma and Beam Physics Research Facility, Chiang Mai University, Chiang Mai, Thailand,
Dec. 6, 2016.
Status of test-Accelerator as Coherent THz Source (t-ACTS) at ELPH, Tohoku University (Oral presentation)
S. Kashiwagi, T. Abe, F. Hinode, K. Kanomata, T. Muto, K. Nanbu, I. Nagasawa, H. Saito,
Y. Saito, K. Takahashi and H. Hama
Workshop on THz FEL, Hefei, China, Dec. 22, 2016.
Implementation of an electron storage ring for GeV-gammma beam production via Bremsstrahlung in
an internal target wire (Oral presentation)
T. MutoThe 1st International Workshop on CSR and free electron lasers from ultra short bunch elec-

100tron beam, Uji Kyoto, Japan, Sep. 2, 2016.
Study of Cherenkov radiation from thin silica-aerogel (Oral presentation)
K. Nanbu, S. Kashiwagi, F. Hinode, T. Muto, I. Nagasawa, K. Takahashi, H. Saitoh, T. Abe,Y. Saitoh and H. Hama,
13th Eco-Energy and Materials Science and Engineering Symposium, Udonthani, Thailand,
Dec. 2, 2016.
Demonstration of coherent radiation generation up to 3 THz from femtosecond electron pulses (Oralpresentation)
T. Abe, S. Kashiwagi, F. Hinode, T. Muto, K. Nanbu, K. Takahashi, I. Nagasawa, K. kanomata,H. Saito, Y. Saito and H. Hama
13th Eco-Energy and Materials Science and Engineering Symposium, Udonthani, Thailand,
Dec. 2, 2016.
Observation of coherent transition radiation from extremely short electron beam (Oral presentation)
T. Abe, S. Kashiwagi, F. Hinode, K. Kanomata, T. Muto, K. Nanbu, I. Nagasawa, H. Saito,
Y. Saito, K. Takahashi and H. Hama
Workshop on THz FEL, Hefei, China, Dec. 22, 2016.
Coherent THz wave observed by a Michelson interferometer (Oral presentation)
T. AbeThe 1st International Workshop on CSR and free electron lasers from ultrashort bunch electron beam, Uji Kyoto, Japan, Sep. 1, 2016.
e+p project at ultra-low Q2 in Japan (Invited oral)
T. Suda
ECT∗ workshop on the Proton Radius Puzzle, ECT∗ , Trento, Italy, June 20–24, 2016.
Future perspectives of the SCRIT facility (Invited oral)
T. SudaElectron-radioactive ion collisions : theoretical and experimental challenges, Gif-sur-Yvette,
France, Apr. 25–27, 2016.
SCRIT electron scattering facility : present status and future perspectives (Invited oral)
T. SudaNeutron Skin of Nuclei, Mainz, Germany, May 17–27, 2016.
Electron scattering experiment off proton at ultra-low Q2 (Invited oral)
T. SudaMeson in Nuclei 2016, Kyoto, Japan, Aug. 1–3, 2016.
Electron scattering experiment off proton at ultra-low Q2 (Invited oral)
T. SudaStrangeness Nuclear Physics School 2016, Sendai, Japan, Nov. 18–20, 2016.
Electron scattering activities for nuclear physics in Japan (Seminar)
T. Suda101
Seminar at Peking University, China, Mar. 20, 2016.
Electron scattering experiment off proton at ultra-low Q2 (Seminar)
T. SudaSeminar at Shandong University, China, Mar. 28, 2016.
Electron scattering off short-lived nuclei at SCRIT facility (Seminar)
T. SudaSeminar at GANIL, CAEN, France, Apr. 29, 2016.
Electron scattering activities for nuclear physics in Japan (Seminar)
T. SudaSeminar at IBS, Daejeon, Korea, Mar. 6, 2017.
Electron scattering activities for nuclear physics in Japan (Seminar)
T. SudaSeminar at Seoul University, Seoul, Korea, Mar. 8, 2017.
First result from SCRIT electron scattering facility: Charge density distribution of 132 Xe (Oral presentation)
K. Tsukada
International Nuclear Physics Conference, Adelaide Convention Centre, Australia, Sep. 11–
16, 2016.
Experimental Approaches to Strangeness in Neutron Stars (Invited oral)
H. Tamura
14th International Symposium on Nuclei in the Cosmos (NIC14), Toki Messe, Niigata, Japan,
June 19–24, 2016.
Recent Progress in Hypernuclear Physics (Invited oral)
H. Tamura
25th International Nuclear Physics Conference (INPC2016), Adelaide, Australia, Sep. 11–16,
2016.
Strangeness nuclear physics and neutron stars (Invited oral)
H. Tamura
Conference in the YIPQS long-term and Nishinomiya-Yukawa memorial workshop ”Compact
stars and gravitational waves”, Yukawa Institute, Kyoto University, Kyoto, Japan, Oct. 31–
Nov. 4, 2016.
Welcome address and the Neutron Star Matter project (Invited oral)
H. TamuraInternational Symposium on Neutron Star Matter (NSMAT2016) － Recent Progress in Observations, Experiments and Theories －, Tohoku University, Sendai, Japan, Nov. 21–24,
2016.
Oxidative degradation of polyethylene studied by positron annihilation lifetime spectroscopy (Oral presentation)

102
T. Oka, K. Onodera, Y. Kino, T. Sekine
The 12th International symposium on Ionizing Radiation and Polymers (IRaP2016), Peninsula of Giens, France, Sep. 25–30, 2016.
Reactions with heavy nuclei (Invited oral)
K. Hagino
FRIB Theory Alliance Inaugural meeting, Michigan State University, U.S.A., Mar. 31–Apr. 1,
2016.
Di-neutron correlation and two-neutron decay of the 26 O nucleus (Invited oral)
K. Hagino
YITP one-day workshop on NN and quartet correlations in nuclei, Yukawa Institute for Theoretical Physics, Kyoto, Japan, June 27, 2016.
Theoretical challenges in fusion reactions relevant to superheavy elements (Invited oral)
K. Hagino
RIBF Users meeting, RIKEN, Wako, Japan, Sep. 8–9, 2016.
Role of nn-correlations in the two-neutron decay of the 26 O nucleus (Invited oral)
K. Hagino
ECT∗ workshop on Physics beyond the limits of stability: exploring the continuum, ECT∗ ,Trento, Italy, Oct. 17–21, 2016.
Di-neutron correlation and BCS-BEC crossover in the structure and decay of light neutron-rich nuclei(Oral presentation)
K. HaginoInternational symposium on neutron star matter (NSMAT2016), Tohoku University, Sendai,
Japan, Nov. 21–23, 2016.
Beyond-mean-field theory for multi-octupole excitations in 208 Pb and subbarrier fusion of 16 O+208 Pb(Invited oral)
K. Hagino
Tsukuba CCS-RIKEN joint workshop, RIKEN, Wako, Japan, Dec. 12–16, 2016.
Application of beyond-mean-field approach to hypernuclei and heavy-ion fusion reactions (Invited oral)
K. Hagino
YITP Molecule workshops on recent progress in nuclear structure physics 2016, Kyoto University, Kyoto, Japan, Dec. 5–23, 2016.
Semi-microscopic modelling of heavy-ion fusion reactions (Invited oral)
K. Hagino
Workshop on Low-Energy Nuclear Reaction Theory (LENRT), Australian National University, Canberra, Australia, Feb. 15–17, 2017.
Evolving theoretical descriptions of heavy-ion fusion: from phenomenlogical to microscopic approaches(Keynote speech)
K. Hagino

103International conference on Fusion17, Hobart, Australia, Feb. 20–24, 2017.
BGOegg experiments at LEPS2 (Invited oral)
H. Shimizu
YITP Workshop – Meson in Nucleus, Yukawa Institute, Kyoto, Japan, Jul. 31–Aug. 2, 2016.
ηn Scattering Length from the γd → pηn Reaction at Eγ ∼ 0.9 GeV (Oral presentation)
T. Ishikawa

14th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon(MENU2016), Kyoto, Japan, July 25–30, 2016.
Simultaneous Photoproduction Of Neutral And Charged Pions On The Deuteron At ELPH (Oral presentation)
T. Ishikawa
The 26th International Nuclear Physics Conference (INPC), Adelaide, Australia, Sep. 11–16,
2016.
ηn scattering length from γd → pηn at Eγ ∼ 0.93 GeV (Oral presentation)
T. Ishikawa

The international symposium on Neutron Star Matter 2016 (NSMAT2016), Sendai, Japan,
Nov. 21–24, 2016.
Development of a high-intensity photon-beam profile monitor (Keynote speech)
T. Ishikawa
IEEE Nuclear Science Symposuim & Medical Imaging Conference, Strasbourg, France, Oct.
29–Nov. 5, 2016.
Study of baryon resonances and meson-nucleon interactions using photoproduction reactions at ELPH
(Invited oral)
T. Ishikawa
2016 JAEA/ASRC Reimei Workshop: New exotic hadron matter at J-PARC, Inha University,
Incheon, Korea, Oct. 24–26, 2016.
Recent status and futre prospect at the LEPS/LEPS2 experiment in Japan (Invited oral)
A.O. Tokiyasu
Many manifestations of nonperturbative QCD, Illhabela , Sao paulo, Brazil, May 1–7, 2016.
Study of the d(γ,K + )ΣπN reaction at LEPS (Oral presentation)
A.O. Tokiyasu
The 14th International conference on Meson-Nucleon Physics and the Structrue of the Nucleon, Kyoto, Japan, Jul 25–30, 2016.
K− pp bound state search at LEPS2 experiment (Oral presentation)
A.O. Tokiyasu
International Symposium on Neutron Star Matter, Sendai, Japan, Nov. 21–24, 2016.
Hypernuclear spectroscopy via the real photo-induced reaction (Oral presentation)
A.O. Tokiyasu

104International workshop on Strangeness Nuclear Physics 2017, Osaka, Japan, Mar. 12–14,
2017.
The Hypernuclear Experimental Program (Invited oral)
S.N. Nakamura
ELBA XIV Workshop Lepton-Nucleus Scattering, Marciana Marina, Isola d’Elba, Italy, June
27–July 1, 2016.
Spectroscopy of Lambda Hypernuclei (Keynote speech)
S.N. Nakamura
Strangeness Nuclear Physics 2017, Osaka, Japan, Mar. 12–14, 2016.
The ππ and πd system in γd → π + π − d measured with the NKS2 (Oral presentation)
H. Kanda

YITP workshop, Meson in Nuclei 2016 (MIN2016), Kyoto, Japan, Jul. 31–Aug. 2, 2016.
Application of an X-Ray Flat Panel Sensor to a GeV Region Gamma-Ray Beam Profile Monitor (Oralpresentation)
H. Kanda
2016 IEEE Nuclear Science Symposium, Strasbourg, France, Oct. 29–Nov. 6, 2016.
Anomalous Heat Generation and Nuclear Transmutation Experiments at Condensed Matter Nuclear
Reaction Division of Tohoku University (Invited oral)
Y. Iwamura
The Satellite Symposium of 20th International Conference on Condensed Matter Nuclear
Science (SSICCF20), Xiamen University, Fujian, China, Sep. 27–30, 2016.
Replication Experiments at Tohoku University on Anomalous Heat Generation Using Nickel-Based Binary Nanocomposites and Hydrogen Isotope Gas (Oral presentation)
Y. Iwamura
The 20th International Conference on Condensed Matter Nuclear Science (ICCF20), Sendai,
Japan, Oct 2–7, 2016.
Anomalous Heat Generation Experiments Using Metal Nanocomposites and Hydrogen Isotope Gas (Oralpresentation)
Y. Iwamura
The 17th Japan CF-Research Society Meeting, National Institute of Technology, Tokyo College, Tokyo, Japan, Mar. 19–20, 2017.
Anomalous Excess Heat Generated by the Interaction between Nano-structured Pd/Ni surface and D2 /H2gas (Oral presentation)
T. ItohThe 20th International Conference on Condensed Matter Nuclear Science (ICCF20), Sendai,
Japan, Oct. 2–7, 2016.
Anomalous Excess Heat Generation by the Interaction between Nano-structured Pd/Ni surface andD2 /H2 gas (Oral presentation)

105
T. Itoh
The 17th Meeting of Japan CF-Research Society, National Institute of Technology, Tokyo College, Tokyo, Japan, Mar. 19–20, 2017.
Observation of 141 Pr by 40 Ar scattering (RBS) on Cs implanted Pd/CaO multi-layer foil with D2 gaspermeation (Oral presentation)
J. Kasagi
The 20th International Conference on Condensed Matter nuclear Science (ICCF20), Sendai,
Japan, Oct. 2–7, 2016.
Low-energy cooperative DD collision in liquid metal and electron screening effect (Oral presentation)
Y. Honda
The 20th International Conference on Condensed Matter nuclear Science (ICCF20), Sendai,
Japan, Oct. 2–7, 2016.

学位論文 (電子光理学研究センター所属)
博士論文「Study of the low-energy d + d reaction in liquid metals」
本多 佑記，平成 28 年度，東北大学
修士論文 「極短電子ビームによるコヒーレントテラヘルツ放射の研究」
阿部 太郎, 平成 28 年度, 東北大学
修士論文 「電磁カロリメータと前方磁気スペクトロメータによる γd → dπ 0 π 0 反応の研究」
井上 陽介, 平成 28 年度, 東北大学

修士論文 「FOREST Upgrade 実験のための MPPC を用いた位置検出器の開発」
白石 健一郎, 平成 28 年度, 東北大学
修士論文 「ラザフォード後方散乱法による Pd/CaO 多層膜票の質量分析」
田島 龍, 平成 28 年度, 東北大学

学位論文 (他機関所属)
修士論文「細分化された鉛ガラスを用いるカロリメータの電磁シャワーによる性能評価」
神崎 伊織,

平成 28 年度，信州大学

修士論文「鉛ガラスを吸収層とするストリップ型カロリメータの性能評価」
井藤 隼人,

平成 28 年度，信州大学

修士論文「SPring-8/LEPS2 のための MPPC Array を用いた beam profile の測定」
三木 克眞,

平成 28 年度，岐阜大学

修士論文「ニュートリノ反応測定実験に用いる高位置分解能 Scintillating Fiber Tracker の開発」
平本 綾美,

平成 28 年度，京都大学

修士論文「ハイパー核崩壊パイ中間子分光実験の系統誤差改善に向けた精密磁場測定」
冨田 翔子,

平成 28 年度，東北大学

修士論文「3Λ H の寿命測定実験のデザイン」
外山 裕一,

平成 28 年度，東北大学

106
修士論文「シグマ陽子散乱実験のための BGO カロリメータシステムの構築」
池田 迪彦,

平成 28 年度，東北大学

修士論文「Σp 散乱実験用エアロゲルチェレンコフ検出器の開発」
小林 和矢,

平成 28 年度，大阪大学

V. Members of Committees

107

Steering Committee
2016

Hiroyuki HAMA*

ELPH

Hajime SHIMIZU

ELPHToshimi SUDA

ELPH

Fujio HINODE

ELPH

Shigeru KASHIWAGI

ELPHNorihito MURAMATSU

ELPH

Hidetoshi KIKUNAGA

ELPH

Hirokazu TAMURA

Graduate School of Science

Satoshi NAKAMURA

Graduate School of Science

Kazushige MAEDA

Graduate School of Science

Kouichi HAGINO

Graduate School of Science

Fuminori MISAIZU

Graduate School of Science

Yasushi KINO

Graduate School of Science

Nobuyuki Uozumi

Graduate School of Engineering

Atsuki TERAKAWA

Graduate School of Engineering

Masaki FUJITA

Institute for Materials Research

Yuji TAKAKUWA

Institute of Multidisciplinary Research for Advanced Materials

Takeo EJIMA

Institute of Multidisciplinary Research for Advanced Materials

Keiichi EDAMATSU

Research Institute of Electrical Communication

Yasuhiro SAKEMI

Cyclotron and Radioisotope Center (until July 31)

Masatoshi ITOH

Cyclotron and Radioisotope Center (from Aug. 1)

Kenji TSUDA

Frontier Research Institute for Interdisciplinary Sciences* Chairperson

108

General Advisory Committee
2016

Hiroyuki HAMA*

ELPH

Hajime SHIMIZU

ELPHToshimi SUDA

ELPH

Hidetoshi KIKUNAGA

ELPH

Hirokazu TAMURA

Graduate School of Science, Tohoku University

Yasushi KINO

Graduate School of Science, Tohoku University

Yasuhiro SAKEMICYRIC, Tohoku University → CNS, University of Tokyo

Kenji TSUDA

Frontier Research Institute for Interdisciplinary Sciences,
Tohoku University

Takahiro IWATA

Faculty of Science, Yamagata University

Daisuke JIDO

Graduate School of Science and Engineering,Tokyo Metropolitan University

Takashi NAKANORCNP, Osaka University

Tomohumi NAGAE

Graduate School of Science, Kyoto University

Hideaki OHGAKI

IAE, Kyoto University

Shigemi SASAKIHSRC, Hiroshima University

Akihiko YOKOYAMA

College of Science and Engineering,
Kanazawa University

Yasuji OURA

Graduate School of Science and Engineering,Tokyo Metropolitan University* Chairperson

109

Program Advisory Committee
2016

Hajime SHIMIZU

ELPHToshimi SUDA

ELPH

Satoshi Nakamura

Graduate School of Science, Tohoku University

Shigeru KASHIWAGI

ELPH

Hidetoshi KIKUNAGA

ELPHAsao YAMAMURA

Institute for Materials Research, Tohoku University

Yasuhisa TAJIMA

Institute of Arts and Sciences, Yamagata University

Hiroaki OHNISHI

RIKEN Nishina Center

Toshiyuki TAKAHASHI *IPNS, KEK

Yoshihiko SHOJILASTI, University of Hyogo

Yasuji OURA

Graduate School of Science and Engineering,Tokyo Metropolitan University

Koichi TAKAMIYA

Research Reactor Institute, Kyoto University* Chairperson

110VI. Approved Experiments

111

平成 28 年度前期採択課題一覧
課題番号

2836

課

題

名

申込責任者

光量子放射化法によるプロメチウム (Pm) 内包金属フラーレンの合成を目的とし

秋山和彦

た RI 製造 II

2837

シンチレーションファイバー検出器の性能評価のためのテスト実験

南野彰宏

2838

J-PARC シグマ陽子散乱実験のためのエアロゲルチェレンコフカウンターの性

三輪浩司

能評価

2839

光量子放射化分析のための光核反応収率の測定 (III)

大浦泰嗣

2840

Large Acceptance Multi-Purpose Spectrometer (LAMPS) Time Projection

Kim, Young

Chamber (TPC) Prototype Beam Test

Jin

FOREST アップグレード実験のための位置検出型シンチレーション検出器の性

時安敦史

2841

能評価

2842

SOI を用いた粒子軌跡測定用ピクセルセンサーの評価

坪山透

2843

PWO ガンマ線検出器の性能評価

宮部学

2844

FOREST 超前方荷電粒子検出で拓く物理

石川貴嗣

2845

コンパクト BPM の開発 II

石川貴嗣

2846

電子ライナックを用いた有用放射性トレーサー製造法の開発

菊永英寿

2847

第 4 周期元素の原子核半減期精密測定

菊永英寿

2848

Photo-production of a Neutral Kaon and/or a Lambda Hyperon on a

金田雅司

deuteron near the threshold
2849

イメージングプレートを用いた Ni-57 放射能強度分布測定による制動放射線プ

高橋健

ロファイル計測と分布測定補正用試料の作製

2850

NKS2 用標識化光子ビームの調整と標識化装置の改善

2851

440 < Eγ < 720 MeV における重水素原子核標的での π π 光生成反応の研

神田浩樹
+

−

神田浩樹

究

2852

J-PARC・E21 実験 (COMET) のための電子スペクトロメータの開発

西口創

112

平成 28 年度後期採択課題一覧
課題番号

課

題

名

申込責任者

2853

吸収体も読み出すサンドイッチ型カロリメータの性能検証

竹下徹

2854

ニュートリノ実験のためのシンチレーションファイバー検出器の位置分解能評価

南野 彰宏

2855

4 年生学生実験：電子ビームによる放射化物生成及び放射線測定

塚田暁

2856

ラジエータ挿入による BST リングのパラメータ測定

石川貴嗣

2857

BST リングのビーム診断、および電子の速度と運動量 (第 5 回加速器ビームを石川貴嗣

使った原子核・素粒子実験実習スクール)

2858

J-PARC シグマ陽子散乱実験のためのエアロゲルチェレンコフカウンターの性

三輪浩司

能評価（２）

2859

NKS2 電磁石中での Multi-gap Resistive Plate Chamber の性能評価

金田雅司

2860

A Direct Lifetime Measurement of The Lambda Hypertriton

永尾翔

2861

ハイパー核直接寿命測定に向けた Λ 粒子寿命測定実験

永尾翔

2863

非標識化領域光子を用いた重水素原子核標的での π π 生成反応の研究

神田浩樹

2864

新光子標識化装置 Taggers の性能評価

田島靖久

2865

COMET 実験用電磁カロリメータの開発

東城順治

2866

PWO ビームモニターの性能評価

宮部学

2867

MPPC-Array を用いたビームプロファイルモニターの開発

時安 敦史

+

−

随時申込

ELPH ANNUAL REPORT 2016
December 2017
Research Center for Electron Photon Science, Tohoku University
1-2-1, Mikamine, Taihaku, Sendai 982-0826, Japan

印刷所 株式会社 東北プリント
仙台市青葉区立町24番24号
TEL 022（263）1166㈹