ELPH
Annual Report 2019

Research Center for Electron Photon Science
Tohoku University

Preface
We are pleased to issue the “ELPH Annual Report 2019” that covers scientific andtechnical activities carried out at Research Center for Electron Photon Science (ELPH),
Tohoku University in FY2019 (April, 2019 to March, 2020).
The ELPH has been in a second organization term of Joint Usage / ResearchCenters. The Joint Usage / Research Centers (JURC) system was engaged in FY2010 by
the Ministry of Education, Culture, Sports, Science and Technology (MEXT) to
encourage and promote collaborative research passing through the border of respective
universities. In FY2018, an interim evaluation for the first half term was performed.
Thanks to great support of ELPH users, we received “A” evaluation. However wehave still suffered shortage of budget that is crucial problem for university accelerator
facilities, such as ELPH. To save the electricity cost, a solid state RF system for thesynchrotron was introduce last spring. Although we had expected a great reduction of
the electricity power consumption, the unit prices increase of it has been significantly
passed the electricity saving.
“The ELPH Symposium”, which is to explore the interest of basic for mutual
collaboration between difference scientific fields, has been annually. In March 2020, the
3rd ELPH symposium had been scheduled and Prof. Ryosuke Kodama, director of theInstitute of Laser Engineering, Osaka University, and Prof. Katsuhiro Sano of Center ofNortheast Asian Studies, Tohoku University were invited to give special lectures.
Unfortunately the symposium was not implemented due to Covid-19 pandemic. Though
it was very much disappointing we hope human beings overcome the pandemic very
soon, and sincerely ask facility users and related scientific field communities forcontinuous supports and cooperation.
November 2020
Director
Hiroyuki Hama

ELPH Annual Report 2019
Contents
Ⅰ. Papers
Performance test of Water Cherenkov Detector for the J-PARC H-Dibaryon Search Experimentꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 1
S.W. Choi, J.K. Ahn, S. Hayakawa, Y. Ichikawa, W.S. Jung, B.M. Kang, S.H. Kim,and H. Sako
Three-dimensional phantom production for a multiple-isotope PET ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 11
Tomonori Fukuchi, Hiromitsu Haba, and Hideki Kikunaga
RI Production for the synthesis of Promethium Endohedral Metallofullerenes by Photon
Activation Method II ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ13
K. Akiyama, T. Suwa, H. Sugiyama, S. Kubuki, H. Kikunaga
Development of novel silicon sensors with high time and spatial resolution ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ17
Taikan Suehara, Yuto Deguchi, Yuto Uesugi, Yu Kato, Ryo Yonamine
Coherent photoproduction of the neutral pion and eta meson on the deuteron ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ23
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, K. Okamura,
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
Neutron-neutron scattering length from positive pion photoproduction ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ27
T. Ishikawa, S.X. Nakamura, and T. Sato
Measure of the equality of two distributionsꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ31
T. Ishikawa
Current status of the FOREST/BLC experiments at ELPHꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ35

T. Ishikawa, K. Aoki, H. Fujioka, Y. Honda, T. Hotta, K. Itahashi, H. Kanda, H. Kawai,
K. Maeda, Y. Matsumura, M. Miyabe, S. Miyata, N. Muramatsu, H. Ohnishi, K. Ozawa,
Y. Sada, H. Shimizu, M. Tabata, A.O. Tokiyasu, and Y. Tsuchikawa for the FOREST/BLC
collaboration
Study on the variation of efficiency and time resolution depending on the electrode material of
Resistive Plate Chamber ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ39
J. Takahashi, H. Ohnishi, M. Miyabe, A. O. Tokiyasu, Y. Sada, C. Yoshida, H. Saito,
M. Turuta, R. Nishikawa, and T. Nobata
Performance Evaluations of Resistive Plate Chamber with R1234ze as eco-friendly gas ꞏꞏꞏꞏꞏꞏ45
Ryota NISHIKAWA, Kazuya NOBATA, Junpei TAKAHASHI,and Hiroaki OHNISHI
The performance study of the aerogel Cherenkov counter for the LEPS2-solenoid experimentꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ51
C. Yoshida, A.O. Tokiyasu, H. Ohnishi, T. Ishikawa, M. Miyabe, H. Saito, J. Takahashi,
M. Tsuruta
Status of LEPS2-solenoid experiment in 2019 ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ55
A.O. Tokiyasu, Y. Sada, and LEPS2 collaboration
Studies for nuclear medium modification of the η′ meson mass at the SPring-8 BGOegg
experiment ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ59
N. Muramatsu, N. Tomida, Y. Matsumura, J.K. Ahn, W.C. Chang, J.Y. Chen, M.L. Chu,
S. Daté, T. Gogami, H. Goto, H. Hamano, T. Hashimoto, 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, T. Maruyama, S. Masumoto, K. Miki, M. Miyabe,
K. Mizutani, H. Nagahiro, T. Nakamura, T. Nakano, T. Nam, T.N.T. Ngan, M. Niiyama,
Y. Nozawa, Y. Ohashi, H. Ohkuma, H. Ohnishi, T. Ohta, M. Oka, M. Okabe, K. Ozawa,C. Rangacharyulu, S.Y. Ryu, Y. Sada, T. Shibukawa, H. Shimizu, R. Shirai, K. Shiraishi,
E.A. Strokovsky, Y. Sugaya, M. Sumihama, S. Suzuki, S. Tanaka, Y. Taniguchi, A. Tokiyasu,
Y. Tsuchikawa, T. Ueda, H. Yamazaki, R. Yamazaki, Y. Yanai, T. Yorita, C. Yoshida,
and M. Yosoi
3D magnetic field mesurement of SCRIT electron spectrometer ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ65
H. Wauke, H. Honda, T. Suda, D. Taki, K. Tsukada

The position and profile measurement of the positron beam line at ELPHꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ69
M. Miyabe, M. Okabe, Y. Sada, H. Saito, J. Takahashi, M. Tsuruta, C. Yoshida,
and GeV-γ group
Development of a spectrometer for ULQ2 experiment ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ75
Y. Honda, T. Aoyagi, C. Legris, T. Goke, K. Ishizaki, H. Kikunaga, Y. Maeda, S. Miura,
M. Miyabe, T. Muto, K. Namba, K. Nanbu, S. Sasaki, T. Suda, K. Takahashi, S. Takayama,
D. Taki, T. Tamae, A. O. Tokiyasu, K. Tsukada, N. Tsukamoto, H. Wauke, and Z. Hang
Development of a silica aerogel Cherenkov detector for π/K separation fitted to the FOREST/BLC
experiment ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ81
T. Yuzawa, Y. Emoto, K. Fujihara, T. Ishikawa, R. Kanai, H. Kawai, S. Kimata, S. Kimura,
A. Kobayashi, M. Miyabe, K. Okuhata, and M. Tabata1 for the FOREST/BLC collaboration
Development of a simple imaging system for radioisotopes using a cooled CCD camera ꞏꞏꞏꞏꞏꞏ95
H. Kikunaga

Ⅱ. Status Report
Status of Accelerator Facilities in FY2019
T. Muto, K. Kanomata, S. Kashiwagi, F. Hinode, S. Miura, I. Nagasawa, K. Nanbu,
K. Shibata, K. Takahashi and H. Hama
User Support Office Report in FY2019
M. Miyabe and The user support office
Radiation Safety Report 2019
Radiatn Safety Office

Ⅲ. List of Publication

Ⅳ. Members of Committees

Ⅴ. Approved Experiments

Ⅰ. Papers

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2500, #2501)

Performance test of Water Cherenkov Detector for the
J-PARC H-Dibaryon Search Experiment
S.W. Choi1 , J.K. Ahn1 , S. Hayakawa2 , Y. Ichikawa2 , W.S. Jung1 , B.M. Kang1 ,S.H. Kim1 , and H. Sako2
1
2

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

Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan

We have developed a water Cherenkov detector (WC) for the H-dibaryon search experiment (E42)
at J-PARC. The WC was designed to suppress low-momentum proton-associated triggers. It consistsof 20 WC modules placed most downstream of the E42 spectrometer. We commissioned a WC moduleusing 460-MeV positrons at ELPH. We measured the individual photomultiplier signals at both endsof the WC module and the summed signal. The number of photoelectrons was obtained as 33.7 ± 0.05
with a custom-made signal mixer. The summed signal was found to decrease the position and angulardependences of the WC output, thereby providing stable online trigger.

§ 1. Introduction
A six-quark H-dibaryon is searched for via 12 C(K− ,K+ ) reaction at 1.8 GeV/c in the J-PARC Hadron
Experimental Facility [1]. Outgoing charged particles are reconstructed with two dipole spectrometers.
The Hyperon spectrometer consists of a conduction-cooled superconducting magnet [2] and a GEM-based
time projection chamber [3] surrounded by 32 plastic scintillators with MPPC readouts. The forward
KURAMA spectrometer constitutes a dipole magnet, three drift chambers, trigger scintillators, a timeof-flight counter, and two Cherenkov detectors. A large array of 20 water Cherenkov detectors (WC) is
placed most downstream of the E42 apparatus. The WC was designed to suppress online triggers due to
low-momentum protons.
We commissioned a WC module using 460-MeV positrons at ELPH. We report the performance ofthe WC, which includes the number of photoelectrons for individual and summed readouts, the position
and angular dependences, and a custom-made mixer logic circuit.

§ 2. Design of Water Cherenkov Detector
The design of the WC structure was based on the small-size WCs of the J-PARC E05 pilot experiment studying Ξ− hypernuclear spectroscopy via (K− ,K+ ) reaction [4]. The WC array is composed of 20
WC modules alternatively stacked in two layers. The WC module is made of 20-mm thick acrylic to forma rectangular hollow vessel with a dimension of 257 × 207 × 1880 mm3 . The acrylic vessel was fixed withpolymerization except the top lid. The inner rectangular pipe was wrapped with Tyvek diffuse reflector
sheets. The top lid was glued later to the vessel with silicone sealant.

- 1 -ELPH Annual Report, Tohoku University (2019)

Fig.1.

Schematic of a water Cherenkov detector for the beam test.

Cherenkov light propagates in water medium and enter photomultiplier tubes (PMT) (Hamamatsu
H11284-100UV) through 5-mm thick UV-transparent acrylic window (ACRYLITE # 000) at both ends ofthe WC. The PMT has UV-transparent quartz window and super bialkali photocathode with the peak
quantum efficiency of 35% at 350 nm. The PMTs are optically coupled to the acrylic window with opticalgrease (RX-688).

§ 3. Beam test with positron beam
We tested a WC module using 460-MeV positrons at Research Center for Electron Photon Science,
Tohoku University (ELPH). The positron beam intensity ranges up to 1 kHz. Fig. 2 represents a photoof the ELPH test setup. The WC was installed between T1 and T2 trigger detectors. The T1 is composedof two plastic scintillation counters, each of which was perpendicularly placed and separated by 2 mm.
At the most downstream, a veto counter with a φ25 hole was installed to reject background events fromelectromagnetic shower. The alternative trigger detector T3 was also prepared in front of the T2 counterto increase the online trigger rate. Detailed information of the detectors is listed in Table 1. The WCdata were collected with 4-fold coincidence trigger.
3.1 Experimental Setup
The WC position and direction were changed using a lifter. We collected data with beam positions
along the y-axis at angles θy = 0◦ and 15◦ , and along the x-axis at an angle θx = 0◦ . The z-axis isdirected in parallel to the beam direction. We also took data at (x, y) = (0.0) with various incident
angles.

- 2 -ELPH Annual Report, Tohoku University (2019)

Fig.2.

Photo of the experimental apparatus.

Detector

Distance [mm]Size [mm]T1

300

13W × 100H × 5T

WC

403.5

257W × 207H × 1880T

T3

1510

50W × 150H × 5T

T2

1650

13W × 100H × 5T

V(Veto)1719

200W × 200H × 5T
(φ25 hole in the center)

Remarks
Plastic Scintillation Counter(Trigger, MPPC Readout)
Water Cherenkov Detector(SBA-UVT PMT Readout)
Plastic Scintillation Counter(PMT Readout)
Plastic Scintillation Counter(MPPC Readout)
Plastic Scintillation Counter(PMT Readout)

Table 1. Locations and sizes of the detectors in the ELPH beam test
3.2 WC Mixer Logic
As the WC signal is involved in the online trigger of the J-PARC E42, it is crucial to make the WC
signal height independent of the hit locations on the WC module. We developed a signal mixer logic totest if the summed signal can be used for the WC trigger signal.

Fig.3.

Photo of the WC mixer logic with two inputs and two outputs.

- 3 -ELPH Annual Report, Tohoku University (2019)

We compared the offline sum of each PMT signal with the online sum output of the mixer logic. The
individual out signal contains a bunch of peaked pulses due to the fast response of the PMT and longtime dispersion from diffuse reflection. This makes it difficult to set stable threshold levels. On the other
hand, the mixed signal shows good pulse shape and helps to set almost constant thresholds throughout
the beam test. The typical pulse shapes of the individual and summed signals are illustrated in Fig.4.

Fig.4.

Pulse shapes of the water Cherenkov detector. Individual PMT and the WC mixer signals
are indicated by arrows.

3.3 LED Calibration
During the beam test, we calibrated each PMT using a LED light source, driven by a clock generator
with a signal width of 25 ns.

hist_bcalib
CountsCountshist_tcalib
3000

5000

4000

2500
3000

2000
1500

2000

1000
1000
500
0
100

120

140

160

180

200

220

0
100

240

ADC [ch]Fig.5.

120

140

160

180

200

220

ADC [ch]

ADC spectra of (left) top and (right) bottom PMTs of the WC using a LED light source.

The measured ADC spectrum is fitted with the single photoelectron response function of the PMT.
The fit function describes a convolution of Gaussian distribution for pedestal and photoelectron peaks,- 4 -ELPH Annual Report, Tohoku University (2019)

Poisson distribution for Cherenkov photon statistics reaching the PMT, and exponential background
distribution [5]. The pedestal position and the PMT gain were deduced from the fit and used for the
ADC to Np.e conversion.

§ 4. Results and Discussion
4.1 Number of photoelectrons
The ADC spectra for two PMTs at both ends were summed and converted to the Np.e distribution
using the equation 1.
Np.e =

ADC − Pedestal
Gain

(1)

We selected the events leaving hits on the T1 detector. Fig 6 shows an Np.e distribution of theWC when the beam hits the center of the WC. The gain and mean values of the Np.e distribution aresummarized in Table 2.

Count

Npe Top8000
7000

Npe Top
Npe Bot

6000

Npe Sum

5000
4000
3000
2000
1000
0

0

20

40

60

80

100

120

140

Number of PhotoelectronsFig.6.

Np.e distributions for individual outputs and their offline sum.

ChannelWC TopWC Bottom
WC SumGain
22.36 ± 0.09
20.59 ± 0.62

Mean Np.e
18.9 ± 0.03
14.8 ± 0.03
33.7 ± 0.05

Table 2. Gain values from the LED calibration in Section 3.3, and mean values of the Np.e distribution using Eq. 1.

The mean value for the summed Np.e distribution was obtained as 33.7. However, The mean value ofthe top PMT signal is different from that of the bottom PMT signals by approximately 4 photoelectrons.
This difference could come from slightly unequal structures between the top and bottom surfaces or, andpossibly nonuniform gap difference between the inner and outer vessels. A possible air gap between the
PMT and optical acrylic window could also contribute the difference.

- 5 -ELPH Annual Report, Tohoku University (2019)

4.2 Position Dependence
4.2.1 Horizontal Position Dependence
The beam hit the WC in every 3 cm along the x-axis in the range from x = −9 cm to x = 9 cm. The
measurement results for Np.e along the x-axis are shown in Fig.7. No significant dependence on the x
position was observed for both individual and summed signals. Furthermore, the results fit very wellNpewith Geant4 optical simulation results.

80

Npe Top
Npe Bot
Npe Sum
G4 Npe Sum

70
60
50
40
30
20
10
0

−10

−5

0

5

10

X Position [cm]Fig.7.

Mean values of Np.e of each channel and their sum along the x-axis

The online output of WC mixer logic is shown in Fig. 8.

Online Sum Mean [ADC]

Graph
800
700
600
500
400
300
200
100
0

−10

−5

0

5

10

X Position [cm]Fig.8.

Scanned mean of ADC distribution of WC mixer output along x-axis

It also shows no significant position dependence along the x-axis. The variation in mean ADC
values was kept within 10%, referenced to the value for the beam position hitting the center.
4.2.2 Vertical Position Dependence
We also measured the y position dependence in every 10 cm steps, from the center to y = 80 cm. To
confirm the reliability of the measurement, we also took the data at y = −30 cm and y = −60 cm. The- 6 -ELPH Annual Report, Tohoku University (2019)

Npe

results of the offline and online analysis are shown in Fig.9 and Fig.10.

Npe Top
Npe Bot
Npe Sum
G4 Npe Sum

120

100

80

60

40

20

0
−60

−40

−20

0

20

40

60

80

Y Position [cm]Fig.9.

Mean values of Np.e of individual channels and their sum along the y-axis.

Online Sum Mean [ADC]

Graph
800
700
600
500
400
300
200
100
0

−60

−40

−20

0

20

40

60

80

Y Position [cm]Fig.10.

Mean values of the ADC distribution of the WC mixer output along the y-axis

While a large change is predicted in the output along y-axis, the measurement results show no sucha large position dependence.
4.3 Incident Angle Dependence
We measured the signals in every 20 cm steps from y = 0 to 80 cm at the incident angle y 0 = 15◦ .
The measured results are compared with the y = 0◦ results. In the central region for y < 40 cm,
the WC mixer outputs are almost identical at the angles of 0◦ and 15◦ .
4.4 Linearity
The online sum signal of the WC mixer logic was found to be linearly proportional to the summed
value of the two PMT ouputs obtained in offline analysis, which verified the performance of WC mixer

- 7 -

Npe

ELPH Annual Report, Tohoku University (2019)

Npe Sum 0°80

Npe Sum 15°

70
60
50
40
30
20
−60

−40

−20

0

20

40

60

80

Y Position [cm]Fig.11.

Measured numbers of photoelectrons along the y-axis when the beam is incident at (red)0◦ and (blue) 15◦ .

logic for the online trigger. Fig.12 represents a correlation between online mixer and offline sum signals.
The scatter data were fitted with a straight line.

Fig.12.

Scatter plot of the offline sum and online mixer signals.

§ 5. Conclusion
We have constructed a Water Cherenkov detector for the H-dibaryon search experiment (E42) at JPARC. The WC was designed to suppress low-momentum proton-associated triggers. We commissioned
a WC module using 460-MeV positrons at ELPH. We measured the individual photomultiplier signals
at both ends of the WC module and the summed signal. The number of photoelectrons was obtained as
33.7 ± 0.05 with a custom-made signal mixer. The summed signal was found to decrease the position
and angular dependences of the WC output, thereby providing stable online trigger.

- 8 -ELPH Annual Report, Tohoku University (2019)

Acknowledgment
We greatly appreciate to the staff of ELPH for their extensive support and stable beam operation.

References[1]

J.K. Ahn, K. Imai: J-PARC Proposal E42, Search for the H-dibaryon with a large acceptancehyperon spectrometer; J.K. Ahn, Few-Body Syst. 54 (2013) 387390; J.K. Ahn, JPS Conf. Proc. 17(2017) 031004; J.K. Ahn, Proc. Sci. (2018) 124, Hadron 2017.

[2]

J.K. Ahn, et al., IEEE Trans. Appl. Supercond. 26 (2016) 4002105.

[3]

S.H. Kim et al.: Nucl. Instrum. Meth.A 940 (2019) 359-370.

[4]

T. Gogami et al.: Nucl. Instrum. Meth.A 817 (2016) 70-84.

[5]E.H. Bellamy et al.: Nucl. Instrum. Meth.A 339 (1994) 468-476.

- 9 -ELPH Annual Report, Tohoku University (2019)- 10 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2887)

Three-dimensional phantom production for a multiple-isotope PET
Tomonori Fukuchi1, Hiromitsu Haba2, and Hideki Kikunaga3
1

RIKEN Center for Biosystems Dynamics Research, Kobe, 650-0047

2

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

3

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

We have been developing a new type of positron emission tomography (PET), which can detect the
prompt γ-ray with the positron-electron annihilation photons, for multiple-tracer imaging. To evaluate theperformances of the developing system, we produced a three-dimensional imaging phantom using thephotonuclear reaction of natTi(γ,xn)44Ti. We performed an imaging experiment with the produced 44Ti phantom
using the developing PET system and succeeded in reconstructing three-dimensional image of phantom.

§1. Introduction
Positron emission tomography (PET)
imaging is widely used for various objects
to obtain a three-dimensional distributionof positron emitting radioisotopes. A
conventional PET imaging system cannot
identify tracer nuclide, because of theconstant energies of positron-electron
annihilation photons. Accordingly, weFig. 1. Configuration and photograph of Ti targets for threedimensional imaging phantoms.

have been developing a new type of PET system, which can identify the tracer nuclide by detecting
coincidence γ-ray with annihilation photons [1].
In order to evaluate the performances of the developing PET system, it is necessary to perform thephantom imaging, which visualize the known radio-tracer distributions. Therefore, we produced a threedimensional radio-active phantom of 44Ti, which is a longlived parent nuclide of a positron-γ emitter 44Sc, using thephotonuclear reaction.

§2. Three-dimensional phantom production
To produce the three-dimensional phantoms, weprepared natTi targets, which have cylindrical shape with 40mm in diameters and 20-mm thicknesses with cylindricalholes. Figure 1 shows a configuration and photograph of the- 11 -

Fig. 2. Target setup for the 44Ti phantom
production.

ELPH Annual Report, Tohoku University (2019)

targets. The target setup for the photon irradiation is shown in Fig. 2. The high-energy photon irradiation was
performed for 7 hours by the ELPH accelerator with an electron energy of 55.5 MeV, and 44Ti was producedin the natTi(γ, xn)44Ti reactions (nat: natural isotopic abundance). Titanium-44 decays into 44Sc with a half-lifeof 59.1 years, and 44Sc is a positron-γ emitter (γ-ray
energy: 1157 keV) with a half-life of 3.85 hours [2].
Although the most of short-lived by-products wereTable 1. Phantom radio-activities in 600 days
after the irradiation.

attenuated for a few days after the irradiation 46Sc (T1/2

Phantom-1

Phantom-2

44

Ti

1.25 kBq

0.70 kBq

46

Sc

84.8 kBq

48.1 kBq

44= 83.79 days) remaied with Ti. The phantom radio44

46

activities of Ti and Sc in 600 days after production
were determined by a HPGe detector as summarized in Table 1.

§3. Imaging experiment
To investigate the performance ofmultiple-isotope PET system, a 24-hours
measurement

using

the

44

Ti

phantom(phantom-1) was performed as shown in Fig.
3. From the annihilation photons and thepromptγ-raydimensional

coincidence

data,

three-

phantom

image

was

reconstructed as shown in Fig. 3. Using the

Fig. 3. Photograph of measurement of 44Ti phantom(phantom-1) and reconstructed image.

44

Ti phantoms, we will perform further

experiments for the multiple-isotope imaging in the future.

Acknowledgments
The authors thank to the facility staffs of ELPH in Tohoku University for supplying the high-quality
electron beam. This work was supported by JSPS KAKENHI Grant Number JP15H04770

References[1] T. Fukuchi et al.: Med. Phys. 44(6) (2017) 2257.
[2] National Nuclear Data Center, Brookhaven National Laboratory, http://www.nndc.bnl.gov/.

- 12 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2886, #2907)

RI Production for the synthesis of Promethium Endohedral
Metallofullerenes by Photon Activation Method II
K. Akiyama1 , T. Suwa1 , H. Sugiyama1 , S. Kubuki1 , and H. Kikunaga2
12Department of Chemistry, Tokyo Metropolitan University, Hachioji, 192.0397

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

To study the stability of M2 @C80 type metallofullerene including Pm, the extraction rate of M2 @C80
for Pm were investigated for the conventional method and newly developed anaerobic extraction method
using TEA/Acetone mixed solvent. Comparison with the conventional method, the extraction rate for
TEA/Acetone is found to be about 3 times larger than that for CS2 solution of the conventional method.
These results show that the M2 @C80 for Pm is possible to be anaerobic species and that the newly
developed method is effective for the extraction of anaerobic metallofullerene species.

§ 1. Introduction
Endohedral metallofullerenes (EMFs) are known as a clathrate compound and are attracting interest 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, 147 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 EMFs using 143 Pm produced by photon activation ofnatural samarium and also reported that their properties such as oxidation state of Pm in fullerene
cage and that the major species of Pm metallofullerenes were found to be Pm@C82 [2]. On the other
hand, the chemical properities of the minor Pm metallofullerenes species, such as M2 @C80 , were still
not investigated.
It is well known that the one of the most famous minor EMF species is M2 @C80 and that this EMF
species is second major among those encapsulating light lanthanide elements [1]. However, it has beenfound that the chemical stability of this EMF species with neutral charge is decreased with incresing ofatomic number while that for the anion species is increased [3]. It is possible that Pm may form a stable
M2 @C80 fullerene with the highest atomic number among the light lanthanoid.

- 13 -

ELPH Annual Report, Tohoku University (2019)

Although it is impossible to discuss directly about the stability of M2 @C80 with homogeneously
encapsulating two promethium atom from experimental data due to the trace amount of Pm,we could
disucuss about that of M2 @C80 with heterogeneously encapsulating Pm and another lanthanide atom
added as a carrier. Here, we report the results of HPLC analysis of Pm EMFs produced by conventional method and also report the quantitative results extracted by newly developed anaerobic fullerene
recovery system.

§ 2. Experimental
2.1 Synthesis of Soot Containig Promethium Endhedral Metallofullerenes
About 1.0 g of Sm oxide were wrapped by Al foil and sealed into quartz tubes. These targets were
irradiated by 50 MeV photon at Research Center for Electron Photon Science in Tohoku University.
Chemically purified 143 Pm from Sm target by prevously reported method [4] was employed for the metallofullerene production. These Pm tracer were dissolved into concentrated nitric acid together with
about 0.5 g of La2 O3 as a carrier and 139 Ce radiotracer as a conparator. This solution was heat to dryness and then EtOH was added for dissolving resultant nitrate salts. This EtOH solution was dropped
on a porous carbon rod with 10 mm diameters and 60 mm length to adsorb the nitrate salts and thendried. This porous carbon rod was placed in an electric tubular furnace and sintered at 700 o C underN2 gas flow. After the sintering, this rod was set into the fullerene 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.
2.2 Conventional fullerene extraction method
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 [6]. This preseparated EMFs solution was evaporated to dryness and then toluene was added to dissolve fullerene
species for the HPLC analysis.
2.3 Anaerobic fullerene recovery system
The soot produced by above mentioned method dissolved to CS2 were recovered from the fullerene
generator by washing the inner wall of this generator. These recovered CS2 solution were introduced
into a glass vessel shown in the figure 1. The CS2 in the vessel is dried in vacuo and then N2 gas wasintroduced into the vessel for replacement to N2 atmosphere. About 280 mL of tetraethylamine/acetone(1 : 3) mixed solution (here after TEA/Acetone) was injected into the vessel from branch sealed with aseptum by use of a syringe. This TEA/Acetone solution was refluxed for 8 hours to extract chemicallyreduced anaerobic metallofullerene species. After the reflux, this solution was filtered to remove insoluble substances such as amorphous carbon. The remained soot on the filter were rinsed by CS2 to recoverremained fullerene species. The γ ray emitted from these solutions were measured by a Ge detector for
the quantitative determination.

- 14 -

ELPH Annual Report, Tohoku University (2019)

N2
Labo-Balloon

Graham Condenser

Three-necked flask
To
VacuumTEA/Acetone
mixed Solvent

Septum

Fig.1. Schematic diagram of a glass vessel for anaerobic extraction of a reduced metallofullerene.

§ 3. Results and Discussion
3.1 Ectraction of M2 @C80 type Pm metallofullerene by Conventional Method
The HPLC retention time of M2 @C80 for La on our Buckyprep column used for HPLC analysis isaround 80 minute. The radioactivity of 139 Ce is observed at HPLC fraction of 81 to 86 minute but notobserved other fraction in 75-92 minute. This observed radioactivity is considered due to M2 @C80 species
containig 139 Ce becasue HPLC retention time of these fractions were almost same as that of M2 @C80 for
La. On the other hand, observed radioactivity of 143 Pm is found in the HPLC fraction of 86 to 91 minuteand not observed in the HPLC fraction of 81 to 86 minute shown in figure 2. These results suggest that
M2 @C80 including 143 Pm is not stable in the air and not easily extracted by the conventional method.

Fig.2. HPLC profile around the retention time of M2 @C80 .

3.2 Extraction of M2 @C80 type Pm metallofullerene by anaerobic Method
From the results of previous subsection, it is found that it is difficult to extract metallofullerene
species which is not stable in the air by the conventional fullerene extraction method because thismethod exposes metallofullerene species to the air. For the extraction of anaerobic metallofullerene, we
tried to develop the anaerobic extraction method for radioactive metallofullerenes. As shown in figure 3,
the differences in the extraction process between conventional method and anaerobic method are the insertion of the process using glass vessel shown in figure 1 for the replacement of solvent to TEA/acetone
and the reflux in this solvent before the filtration. The ratio of radioactivity in finally obtained solution- 15 -

ELPH Annual Report, Tohoku University (2019)

to radioactivity used for metallofullerene production is defined as the extraction rate and these rate areindicated in the table 1. The numerical notations given for finaly obtained each solvent sample in the
figure 3 correspond to the number indicated in table 1. Comparing these values, it was found that theextraction rate of 143 Pm metallofullerene in the TEA/acetone solution was about 3 times larger thanthat of the conventional method. These results show that the M2 @C80 for Pm is possible to be anaerobic
species and that the newly developed method is effective for the extraction of anaerobic metallofullerene
species.

ŽŶǀĞŶƚŝŽŶĂůDĞƚŚŽĚ

^Ϯ ^ŽůƵƚŝŽŶǁŝƚŚZ/^ŽŽƚ&ŝůƚƌĂƚŝŽŶϭ^Ϯ ^ŽůƵƚŝŽŶŽĨƌƵĚĞZ/&ƵůůĞƌĞŶĞǆƚƌĂĐƚŶĂĞƌŽďŝĐǆƚƌĂĐƚŝŽŶDĞƚŚŽĚ
ŶĂĞƌŽďŝĐ WƌŽĐĞƐƐ
ƌǇƵƉŽĨ^ϮdͬĐĞƚŽŶĞ
^Ϯ ĨŽƌZŝŶƐĞ

ZĞĨůƵǆĨŽƌϴŚŽƵƌƐ
&ŝůƚƌĂƚŝŽŶ

/ŶƐŽůƵďůĞ^ƵďƐƚĂŶĐĞ

ϯdͬĐĞƚŽŶĞ^ŽůƵƚŝŽŶŽĨƌƵĚĞZ/&ƵůůĞƌĞŶĞŶŝŽŶǆƚƌĂĐƚϮ^Ϯ ^ŽůƵƚŝŽŶŽĨZĞƐŝĚƵĂůZ/&ƵůůĞƌĞŶĞ

Fig.3. Comparison of conventional method with newly developed anaerobic extraction method.

Table 1. Extraction rate of Pm and Ce metallofullerenes
No.
1
2
3

Extracted in
CS2 (Conventional)
CS2 (Anaerobic)
TEA/Acetone (Anaerobic)

143

Pm
0.018 %
0.016 %
0.060 %

139

Ce
0.047 %
0.0056 %0.057 %

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]

A. Velloth et al.: J. Phys. Chem. C 121 (2017) 18169.

[4]

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

[5]

K. Akiyama et al.: ELPH Annual Rep. (2016) 72.

[6]

K. Akiyama et al.: ELPH Annual Rep. (2016) 72.

- 16 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2935)

Development of novel silicon sensors with high time andspatial resolution
Taikan Suehara1 , Yuto Deguchi2 , Yuto Uesugi2 , Yu Kato3 , and Ryo Yonamine4
12
3

Department of Physics, Faculty of Science, Kyushu University, Fukuoka, 819-0395

Department of Physics, Graduate School of Science, Kyushu University, Fukuoka, 819-0395

Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033
4

Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578

Silicon pad sensors with novel functions of higher timing resolution (LGAD: Low Gain Avalanche
Detector) and higher position resolution (PSD: Position Sensitive Detector) are studied for an application
to Silicon-Tungsten electromagnetic calorimeter for a detector of the International Linear Collider (ILC).
Prototype sensors are fabricated, equipped with dedicated ASICs (Application-Specific Integrated Circuits) and tested with a positron beam as well as a radioisotope. The first results of the measurementsof timing resolution with LGADs and position reconstruction with PSDs are reported.

§ 1. Introduction
The International Linear Collider (ILC) is a future electron-positron collider for precise measurements of Higgs bosons and various BSM searches. Silicon-tungsten electromagnetic calorimeter (SiWECAL) is one of the candidates to be used in the International Large Detector (ILD) [1], one of thedetector concepts for the ILC. We are proposing two types of new silicon sensors, Low Gain Avalanche
Detectors (LGADs) and Position Sensitive Detectors (PSDs) to be replaced to the standard silicon padsof SiW-ECAL. LGADs are possible to obtain precise timing information and PSDs are sensitive to hit
positions within a cell. With LGADs and PSDs position and timing resolution of the SiW-ECAL canbe significantly improved, which should proceed further reach of Higgs and BSMs in the ILC physics
program.
LGADs are silicon sensors with the internal avalanche amplification, which have already been
proved to realize the timing resolution down to 30 psec [2]. The precise timing information can be
primarily utilized to perform particle identification of hadrons by Time-of-Flight (ToF) method, which
can be combined with dE/dx information obtained in the Time Projection Chamber, which is the main
tracking detector in the ILD.
PSDs are silicon sensors with each cell having an electrode at each corner instead of a simple padspread over the cell. When the signal charge reaches P+ pad, the charge is resistively split to electrodes
via a resistive layer on the surface. The hit position is reconstructed as the gravity center of signal
strengths of the electrodes at the four corners. In contrast to using smaller cells, the position resolution
can be improved with minimal increase of the readout channels if we replace the silicon pads with PSDs

- 17 -

ELPH Annual Report, Tohoku University (2019)

in SiW-ECAL.
We prepared samples for both LGADs and PSDs to demonstrate the possibilities to be used for
SiW-ECAL and to measure characteristics of the sensors for the optimization. We have conducted measurements with the positron beam provided from ELPH as well as particles from radioisotopes.

§ 2. Setup of the test beam
Testboard
(PSD)

beam

Activecollimator

Daughterboards for
LGAD sensors

Testboard(LGAD)

Fig.1. Overview of the setup of LGAD/PSD measurement. The positron beam penetrates up to
6 LGADs and a PSD to obtain concurrent signal.

Figure 1 shows the overview of the setup. The LGADs and PSDs are equipped with testboards of
Skiroc2-CMS ASIC (Application-Specific Integrated Circuit). Skiroc2-CMS has 64-channel readout forsilicon sensors with precise charge and timing information. The timing jitter is ∼30 psec with charge of> 150 fC with dynamic range of ADC > 1000 fC. The timing information is obtained via clock count of
40 MHz and analog 12-bit Time-of-Arrival (ToA), which clips the voltage sweeping within a clock. The
non-linearity of ToA and time walk are corrected using measurements with charge injection.
Up to 6 LGADs were stacked with single testboard to obtain correlation of the signal from penetrating beam. The testboards with LGADs and PSDs were synchronized with a common-stop signal.
Self-triggering with LGADs were used for the common stop. An active collimator, which is a plastic
scintillator with a center hole, placed in front of the sensor stack. The optical readout of the collimatoris done by PMT, connected to a remaining channel of the testboard.

§ 3. Results with the LGADs
The sensors we have tested at the beam is listed in Table 1 [3]. Some sensors are designed as
Avalanche Photo-Diodes (APDs) which are used for optical photon measurements with avalanche gain.
We recognized those as prototype of LGADs since the basic structure is the same. There are also prototypes of LGADs developed in Hamamatsu (pkg-10 and pkg-20) which were also tested with beam. There
are two types of LGADs/APDs, reach-through type and inverse type. The reach-through type has provenperformance of timing resolution, but since the amplification region is confined below the readout pads,
there is significant inactive area. In contrast, the inverse type has amplification on the bottom of the- 18 -

ELPH Annual Report, Tohoku University (2019)

Table 1. List of LGADs and APDs tested with beam at ELPH, Tohoku University.
Spec No.
S12023-10A
S2384
S8664-10K
S8664-20K
S8664-55
pkg-10
pkg-20Type
Reach-throughReach-throughInverseInverseInverseReach-throughReach-through

Size
ϕ1
ϕ3
ϕ1
ϕ2
5×5
ϕ1
ϕ1

Count #1
1002
4355
613
368
3060
1687
1956

Count #2
965
5796
298
185
2327
1584
3010

Count #1&#2
147
1136
4
2
96
15
219

Efficiency
14.9%
22.4%
0.9%
0.7%
3.6%
0.9%
8.8%

sensor, which should result in more uniform response over the surface.
The Table 1 also shows the number of single and coincidence counts with the beam injection. The
sensors are placed to be penetrated by the beam, but we have no selection of the angle of the beam sosome fraction of the particles can geometrically hit only one sensor, depending on the sensor size. From
the table we see coincidence ratio of the inverse APDs are significantly smaller than the reach-throughAPDs. The possible reason is hit-by-hit fractuation of the gain at the inverse-type APDs, but moreinvestigation is necessary to confirm this.

Fig.2. Timing correlation of two APDs (S2384) without selection (left) and with selection of> 100 fC (right).

Timing resolution of reach-through APDs (S2384) were measured with the ToA data of the coincidence events. After the correction of non-linearity and time-walk of the ToA, we see clear correlation
between two sensors as shown in Figure 2 (left). Figure 2 (right) shows the correlation of events having> 100 fC of charge to avoid jitter of the electronics. The timing resolution of single sensor was calculated
as 385 ± 94 psec. The result is worse than expected. Possible reason is imperfect correction of ToA since
the correction coefficients are obtained with measurements at different places. We will investigate thiswith further measurements.

- 19 -

ELPH Annual Report, Tohoku University (2019)

Fig.3. Picture of a PSD (left) and magnified view of resistive P+ surface (top-right, left-half of
the PSD) and resistive layer surface (bottom-right, right-half of the PSD).

§ 4. Results with the PSDs
We fabricated a few types of PSDs having 4×4 cells, shown in Figure 3. Each cell has an electrodeat each corner, having 64 readout channels in total. One of the important parameters of the PSDs is thesurface resistance. The PSDs have two types of the resistive layer in each side. One is a resistive P+
surface, which forms meshes to increase the resistivity. The other is a dedicated resistive layer connected
to a dotted P+ layer, which gives 10-30 times more resistance [4]. The resistivity of the edges of the PSDs
is set lower to reduce position distortion. The cell size is 5.5 × 5.5 mm2 , and the sensor thickness is 650µm for all the sensors.

Fig.4. Reconstructed position of each cell with a PSD, with beta radiation from 90 Sr.

Figure 4 shows the response of the PSD sensors with a 90 Sr radioactive source. The position is- 20 -

ELPH Annual Report, Tohoku University (2019)calculated by(Q0 + Q1 ) − (Q2 + Q3 )Q0 + Q1 + Q2 + Q3
(Q0 + Q2 ) − (Q1 + Q3 )Yrec =
Q0 + Q1 + Q2 + Q3

Xrec =

where Xrec and Yrec are the reconstruction position in X and Y axes and Qi is measured charge at eachelectrode on the corner. The difference between maximum and minimum Xrec (Yrec ), called “dynamic
range” should be −1 to 1 in an ideal case. The figure shows almost maximum dynamic range is obtainedwith the resistive layer (right side of the figure). The concentration of the events at Xrec = Yrec = ±1 isbecause of a threshold effect of the trigger on single channel instead of sum of four channels in a same
cell, due to the limitation of the electronics.
The PSDs were also irradiated with positron beam, but due to higher environmental noise at beamline it is difficult to reconstruct positions with the obtained results. Further studies are expected withmore appropriate electronics and shielding.

§ 5. Summary
LGADs/APDs and PSDs sensors have been studied for the application to ILD SiW-ECAL. The firstmeasurement of the timing resolution of the APDs with positron beam is obtained as 385 ± 94 psec,
which we will try to improve with updated setup. We successfully reconstructed the hit positions on
PSDs with good dynamic range using a 90 Sr radioactive source. Further studies with positron beam areplanned.

Acknowledgments
The test beam experiment was conducted with the support of ELPH, Tohoku University. We appreciate Omega group for the support on the operation of the Skiroc2-CMS chip. This work is partially
supported by JSPS KAKENHI Grant Number JP17H05407.

References[1]

T. Behnke, James E. Brau, Philip N. Burrows, M. Peskin, et al., The International Linear Collider
Technical Design Report - Volume 4: Detectors, arXiv:1306.6329 (2013).

[2]

McCarthy, Thomas G., Upgrade of the ATLAS Liquid Argon Calorimeters for the High-Luminosity
LHC, arXiv:1612.07102 (2016).

[3]

Y. Deguchi, K. Kawagoe, E. Mestre, R. Mori, T. Suehara, T. Yoshioka, Study of silicon sensors for
precise timing measurement, 2020 JINST 15 C05051.

[4]

Y. Uesugi, R. Mori, H. Yamashiro, T. Suehara, T. Yoshioka, K. Kawagoe, Study of Position Sensitive
Silicon Detector (PSD) for SiW-ECAL at ILC, 2020 JINST 15 C05033.

- 21 -

ELPH Annual Report, Tohoku University (2019)- 22 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2623, #2640, #2655, #2694, #2710)

Coherent photoproduction of the neutral pion and eta
meson on the deuteron
T. Ishikawa1 , H. Fujimura1∗ , H. Fukasawa1 , R. Hashimoto1† , Q. He1‡ ,Y. Honda1 , T. Iwata2 , S. Kaida1 , 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 , S. Takahashi1 , 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, Japan

Coherent photoproduction of the neutral pion (π 0 ) and eta meson (η) on the deuteron (d), γd→π 0 ηd,
has been experimentally studied at incident photon energies ranging from the reaction threshold to 1.15
GeV. The total cross section as a function of the incident energy is higher than the existing theoretical
calculation without any final-state interaction (FSI) based on quasi-free π 0 η photoproduction on the
nucleon (N ) with deuteron coalescence. The calculation reproduces the data below 1 GeV including
FSIs (meson scattering and absorption of an additionally produced meson on the spectator nucleon,
and many-body interaction of mesons with the final-state deuteron). We have measured the differential∗

Present address: Department of Physics, Wakayama Medical University, Wakayama 641-8509, Japan†

Present address: Institute of Materials Structure Science (IMSS), High Energy Accelerator Research
Organization (KEK), Tsukuba 305-0801, Japan‡

Present address: Department of Nuclear Science and Engineering, Nanjing University of Aeronautics
and Astronautics (NUAA), Nanjing 210016, China§

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

Present address: Gunma University Initiative for Advanced Research (GIAR), Maebashi 371-8511,
Japan

∥

Present address: The Wakasa Wan Energy Research Center, Tsuruga 914-0192, Japan∗∗

Present address: J-PARC Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, Japan††

Present address: Radiation Science Center, High Energy Accelerator Research Organization (KEK),
Tokai 319-1195, Japan- 23 -

ELPH Annual Report, Tohoku University (2019)cross sections dσ/dMπη , dσ/dMπd , dσ/dMηd , and dσ/dΩd in the γd center-of-mass frame for the firsttime. The measured angular distributions of deuteron emission do not show strongly backward-peaking
behavior predicted by the calculation, as well as that in the γd → π 0 π 0 d reaction. This suggests a
different reaction mechanism from the calculations, and a possible mechanism would be a sequential
reaction γd → DIV → π 0 DIS → π 0 ηd and/or γd → DIV → ηDIV → π 0 ηd with an isoscalar dibaryon DIS
and an isovector dibaryon DIV . At the highest incident energy, an enhancement is observed near the ηdthreshold. The spin-parity of this state is found to be 1− , which corresponds to an S-wave ηd and/or
S-wave N (940)1/2+ and N (1535)1/2− .

§ 1. Introduction
Coherent simultaneous photoproduction of the neutral pion (π 0 ) and eta meson (η) on the deuteronγd → π 0 ηd has a unique feature for studying properties of hadron structures and interactions. Owing
to absence of a ∆-Kroll-Ruderman term and a meson-pole term, a minor effects can be observed such as
distortion of cross sections by the final-state interactions (FSIs), and sequential dibaryon production in
the intermediate states.

§ 2. Experiment
Meson photoproduction experiments with an electromagnetic calorimeter complex FOREST [1]were carried out from May 2008 to May 2010 at the Research Center for Electron Photon Science (ELPH),
Tohoku University, Japan [2]. Bremsstrahlung photons were used from the circulating 1.2-GeV electrons
in the STretcher booster (STB) ring [3]. The photon energy was tagged with a photon tagging counter
STB-Tagger II [4]. The energies of the tagged photon beam ranged from 740 to 1150 MeV. The finalstate particles were detected with the FOREST detector. The trigger condition of the DAQ system wasmade for detecting more than one final-state particle coincident with a photon-tagging signal. In theanalysis stage , the events containing four neutral particles and a charged particle were selected. The
γd → π 0 ηd event selection was made finally by applying a kinematic fit with six constraints: the energy
and three-momentum conservation, the invariant mass of two photons out of four being the π 0 mass,and the invariant mass of the other two photons being the η mass.

§ 3. Cross sections
The total and differential cross sections were measured for the γd→π 0 ηd reaction at the incident
energy ranging from the reaction threshold to 1.15 GeV. The analysis of the γd → π 0 ηd reaction was
similar to that of the γd → π 0 π 0 d reaction described in Ref. [5]. The total cross section as a function of γdcenter-of-mass system Wγd does not show a resonance-like behavior. The existing theoretical calculation
without any final-state interaction (FSI) based on quasi-free π 0 η photoproduction underestimates thedata [6]. The calculation reproduces the data below 1 GeV including meson scattering and absorption ofan additionally produced meson on the spectator nucleon [6], and many-body interaction of mesons withthe final-state deuteron.

- 24 -

ELPH Annual Report, Tohoku University (2019)

We have measured the differential cross sections dσ/dMπη , dσ/dMπd , dσ/dMηd , and dσ/dΩdin the γd center-of-mass frame for the first time. Similarly to the γd → π 0 π 0 d reaction, the angular distribution of deuteron emission is rather flat, and the kinematic condition for the obtained data
completely differs from the calculation, suggesting a manifestation of dibaryons also in the γd → π 0 ηdreaction. A possible mechanism would be a sequential reaction γd → DIV → π 0 DIS → π 0 ηd and/or
γd → DIV → ηDIV → π 0 ηd with an isoscalar dibaryon DIS and an isovector dibaryon DIV . In the observed reaction, both the two nucleons obviously participate before emitting π 0 and η.
The dσ/dMηd shows a strong enhancement near the ηd threshold at all the incident energies. The
S-wave ηd decay of DIS must be dominant, giving a spin-parity of 1− for DIS . since a prominent peaknear the threshold can be produced if and only if L = 0. We confirm the spin-parity of this state fromangular distributions of π 0 and η obtained for the events from Mηd < 2.47 GeV. The spin-parity of 1−
corresponds not only to an S-wave ηd state but also an S-wave N (940)1/2+ and N (1535)1/2− state.
Additionally, the real part of the ηd scattering length is determined so that it reproduces the measured
dσ/dMηd distributions. We cannot determine its sign but obtain an absolute value of 1.2 ± 0.2 fm which
is a half of the theoretical estimation by Fix et al [7].

§ 4. Summary
We have measured and analyzed the γd → π 0 ηd reaction. The total cross section as a function of γdcenter-of-mass system Wγd is reproduced below 1 GeV by the existing calculation including meson scattering and absorption of an additionally produced meson on the spectator nucleon [6], and many-bodyinteraction of mesons with the final-state deuteron. We also investigate the properties of the thresholdenhancement in the dσ/dMηd , and its spin-parity is found to be 1− . Since the data analysis has been
finalized, and the corresponding paper will be submitted soon. Details of the analysis and discussion
will be given in the forthcoming arXiv preprint.

Acknowledgment
The authors express gratitude to the ELPH accelerator staff for stable operation of the accelerators in the FOREST experiments. They acknowledge Mr. Kazue Matsuda, Mr. Ken’ichi Nanbu, and
Mr. Ikuro Nagasawa for their technical assistance in the FOREST experiments. They also thank Prof.
Mikhail Egorov for the theoretical calculations of the cross sections. This work was supported in part by
the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) and Japan Society for
the Promotion of Science (JSPS) through Grants-in-Aid for Specially Promoted Research No. 19002003,
for Scientific Research (A) Nos. 24244022 and 16H02188, for Scientific Research (B) Nos. 17340063 and
19H01902, for Scientific Research (C) No. 26400287, and for Scientific Research on Innovative Areas
Nos. 19H05141 and 19H05181.

- 25 -

ELPH Annual Report, Tohoku University (2019)

References[1]

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

[2]

T. Ishikawa et al.: JPS Conf. Proc. 10 (2016) 031001;
T. Ishikawa et al.: Phys. Rev. C 101 (2020) 052201 (R).

[3]

F. Hinode et al.: Proc. of 21st IEEE Particle Accelerator Conference (PAC) (2005) 2458.

[4]

T. Ishikawa et al.: Nucl. Instrum. Meth. A 622 (2010) 1;
T. Ishikawa et al.: Nucl. Instrum. Meth. A 811 (2016) 124;
Y. Matsumura et al.: Nucl. Instrum. Meth. A 902 (2018) 103;
Y. Obara et al.: Nucl. Instrum. Meth. A 922 (2019) 108.

[5]

T. Ishikawa et al., Phys. Lett. B 772 (2017) 398; ibid. 789 (2019) 413.

[6]

M. Egorov: Phys. Rev. C 101 (2020) 065205.

[7]

A. Fix and O. Kolesnikov: Phys. Rev. C 97 (2018) 044001.

- 26 -

ELPH Annual Report, Tohoku University (2019)

Neutron-neutron scattering length from positive pion
photoproduction
T. Ishikawa1 , S.X. Nakamura2,3 , and T. Sato4
1

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

2

State Key Laboratory of Particle Detection and Electronics, University of Science and Technology
of China, Hefei 230036, China
3

Department of Modern Physics, University of Science and Technology of China, Hefei 230026,
China
4

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

We have considered the possibility of extracting the neutron-neutron scattering length ann to investigate charge symmetry breaking from the final-state interaction in positive pion photoproduction.
Details are described in a preprint submitted to arXiv [S.X. Nakamura, T. Ishikawa, and T. Sato, arXiv:
2003.02497 (2020)].

§ 1. Charge symmetry breaking
Charge symmetry (CS) is an important concept for describing many facets of nuclear physics: observables are hardly changed when all protons and neutrons are replaced with neutrons and protons,
respectively. CS corresponds to invariance under the interchange of u and d quarks, and CS breaking (CSB) takes place owing to differences of u and d masses and electromagnetic effects. Recently,
an unexpectedly large difference in the excitation energies is observed between the 4Λ He and 4Λ H mirror hypernuclei [1, 2]. CSB possibly occurs more strongly in hypernuclei than in oridnary nuclei. The
full understanding of CSB still remains an open issue in nuclear physics. To reveal the cause of the
CSB, it is important to investigate the low-energy nn and pp scatterings as well as between Λn and Λpscatterings.

§ 2. Positive pion photoproduction
We have considered the possibility of extracting the neutron-neutron scattering length ann to investigate CSB from the final-state interaction (FSI) in positive pion photoproduction, the γd → π + nn reaction. What we have to do is to measure the pion momentum and its direction precisely at a fixed incident
photon energy. An experimental advantage of this reaction is that we can avoid the neutron detection
and uncertainty of its efficiency. A kinematic condition with an incident photon energy of 250 MeV andpion emission angle of 0◦ is suitable for this purpose The differential cross section d2 σ/dMnn /dΩπ issensitive to the value of ann below Mnn = 2Mn + 0.5 MeV where Mnn and Mn denote the nn invariant- 27 -

ELPH Annual Report, Tohoku University (2019)

mass and neutron mass, respectively. It is found that d2 σ/dMnn /dΩπ with 2% error, resolved into Mnn
bins of 0.04 MeV (corresponding to pπ bins of 0.05 MeV/c), can determine ann at a precision of ±0.21
fm with a systematic uncertainty of 0.03 fm.

§ 3. Positive pion electroproduction
High momentum resolutions, at the order better of 10−3 or better, are required for the incident
photon beam and for the emitted positive pion to determine ann precisely. These conditions can beachieved by utilizing virtual photons of very low Q2 from electron scattering at the Mainz MAMI A1
facility [3]. The triple differential cross section for the (e, e′ π) reaction can be described in the following
form (omitting the Mnn differentiation) for the unpolarized photon beam and unpolarized target:
{
}
γd
γd
√
dσLT
dσLγd
dσTT
dσTγd
d3 σ ed= Γγ+ ϵL+ 2ϵL (1 + ϵ)cos ϕπ + ϵ
cos 2ϕπ , (1)dEe′ dΩe′ dΩπ
dΩπ
dΩπ
dΩπ
dΩπ
where σT , σL , σLT , and σTT are the transverse, longitudinal, longitudinal-transverse interference, andtransverse-transverse interference cross sections for γ ∗ d → π + nn in the laboratory frame, respectively [4, 5] with a virtual photon flux Γγ . The σT corresponds to the cross section for the real photon
beam at Q2 = 0, which should be extracted from electroproduction. The σLT and σTT terms vanish when
the pion is detected at θπ = 0◦ with respect to the virtual photon direction. No condition satisfies thatthe σL term is negligibly small among the available beam energies and spectrometer settings. We propose a method to separate σT and σL by taking advantage of the linear ϵL dependence like a Rosenbluth
separation.

§ 4. Summary
We discussed the possibility of extracting the low-energy neutron-neutron scattering length ann
from γd → π + nn cross-section data. High momentum resolutions are required for the photon beam andemitted positive pion, and they can be achieved with an electron scattering experiment at the Mainz
MAMI A1facility. The transverse cross section, corresponding to the real photon cross section, can beseparated from the electroproduction cross sections at different ϵL values but the same Q2 ∼ 0 (analmost-real photon condition). Details of our consideration are described in Ref. [6]Acknowledgment
This work was supported in part by the Japan Society for the Promotion of Science (JSPS) throughGrants-in-Aid for Scientific Research (B) No. 19H01902, and for Scientific Research on Innovative Areas
Nos. 19H05141 and 19H05181.

References[1]

T.O. Yamamoto et al. (J-PARC E13 collaboration): Phys. Rev. Lett. 115 (2015) 222501.

[2]

A. Esser et al. (A1 collaboration at MAMI): Phys. Rev. Lett. 114 (2015) 232501.

- 28 -

ELPH Annual Report, Tohoku University (2019)[3]

K.I. Blomqvist et al.: Nucl. Instrum. Meth. A 403 (1998) 263.

[4]

T. de Forest: Nucl. Phys. A 392 (1983) 232.

[5]

P.J. Mulders: Phys. Rept. 185 (1990) 83.

[6]

S.X. Nakamura, T. Ishikawa, and T. Sato: arXiv: 2003.02497 (2020).

- 29 -

ELPH Annual Report, Tohoku University (2019)- 30 -

ELPH Annual Report, Tohoku University (2019)

Measure of the equality of two distributions
T. Ishikawa1
1

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

The χ2 value is used as a quality of the fit when we fit a function to the data using the least-squares
approximation. In this report, we discuss a measure of the equality of the two distributions based on
Ref. [1].

§ 1. Standard deviation of a set of values
The standard deviation is a measure of the amount of variation of a set of values in statistics.
Suppose we have a set of values x1 , x2 , . . ., xn , and the amount of them is n. The average µ of them is
n
∑

µ=

xi

i=1
n
∑

1

1 ∑
xi
=
n
n

(1)

i=1

i=1

and the standard deviation σ is defined by
n
∑
2

σ =

2

(xi − µ)

i=1
n
∑

1 ∑
2
(xi − µ) =
=
n
n

(

i=1

1

1 ∑ 2
xi
n
n

)
− µ2 .

(2)

i=1

i=1

It should be noted that physicists often use the term root mean square (rms) for σ, and the correct rms
value xrms is given in the equation
( n
)
∑
1
x2rms =
x2i = µ2 + σ 2 .
n

(3)

i=1

§ 2. Standard deviation of a continuous function
In §1, we have discussed the average and standard deviation for a set of values. Here, we discuss
those for a continuous function y = f (x) defined in the domain [xmin , xmax ). The average ⟨f ⟩ can beeasily estimated as∫ xmaxf (x) dx⟨f ⟩ =

xmin∫ xmax

1 dx

1=xmax − xmin

∫ xmaxf (x) dx.
xmin

xmin

- 31 -(4)

ELPH Annual Report, Tohoku University (2019)

In comparison to Eq. (1), xi and∑n

i=1 are replaced with f (x) and∫ xmaxxmin

dx, respectively. The standard

deviation σf is given in the eqation∫ xmax {}2∫ xmax {f (x) − ⟨f ⟩ dx
}2
xmin
1
2
∫
f
(x)
−
⟨f
⟩
dx
σf =
= x
xmax
max − xmin
xmin
1 dx
xmin ∫
xmax {}2
1=
f (x) dx − ⟨f ⟩2 .
xmax − xmin xmin

(5)

The first term of the right-hand side in Eq. (5) corresponds to the rms value of f (x).

§ 3. Equality of two sets of values
We discuss here the equality of two sets of values (or two histograms with the same number of bins)
x1i

and x2i for i = 1, 2, . . . , n. The standard deviation
n
∑

x2i

σ 2 = i=1
n
∑

1 ∑ 2
xi
n
n

=
1

(6)

i=1

i=1

can be used as a measure of the equality when we do not have to make an additional overall normalization. When the equality of the shapes for the two sets is concern and overall normalization can be made,the minimum σ, given by)2
1 ∑( 2xi − cx1i ,
n
n

σ2 =

(7)

i=1

corresponds to a measure of the equality. The σ value depends on the normalization factor c:
{
}
{
}
{
}
n
n
n
1 ∑ ( 1 )2
1 ∑ 1 21 ∑ ( 2 )2
2
2
σ =
xi
c −2
xi xi c +
xi
,
n
n
n
i=1

i=1

(8)

i=1

and the minimum σ is provided when
∂σ 2
= 0.
∂c

(9)

Thus, the normalization factor c for the minimum σ can be directly calculated as{}n
1 ∑ 1 2
xi xi
n
i=1
}.
c= {
n
1 ∑ ( 1 )2
xi
n

(10)

i=1

The minimum σ 2 is obtained by substituting this c to Eq. (7):{}2n1 ∑ 1 2
{
}
xi xi
n
n
1 ∑ ( 2 )2i=1
2}.
σ min =
xi
− {
n
n
∑
(
)
1
2
i=1
x1i
n

(11)

i=1

This σ2mincorresponds to the measure of the equality of the two sets x1i and x2i when overall normal-

ization can be made freely.

- 32 -

ELPH Annual Report, Tohoku University (2019)

When x1i and x2i have uncertainties δx1i and δx2i , respectively, the minimum value of χ2 , given by
χ2 =

( 2
)2
xi − cx1i( 2 )2 ()2 ,+ cδx1ii=1 δxin∑(12)

should be used instead of the minimum σ 2 in Eq. (7). The normalization factor c is obtained from thecondition ∂χ2 /∂c = 0 in principle, but it requires complicated calculations. When x1i does not have an
uncertainty or δx1i = 0 for all the is, n σ 2 min calculated in Eq.( 11) can be used as the measure of theequality by replacing x1i and x2i with x1i /δx2i and x2i /δx2i , respectively.

§ 4. Equality of two continuous functions
Finally, we discuss the equality of two continuous functions f1 (x) and f2 (x) defined in the domain[xmin , xmax ). The standard deviation∫ xmax {}2
f (x) dx
∫ xmax {}2
1
xmin∫ xmax
σf2 =f (x) dx=
xmax − xmin xmin
1 dx

(13)

xmin

can be used as a measure of the equality when we do not have to make an additional overall normalization. When the equality of the shapes for the two sets is concern and overall normalization can be made,the minimum σ, given by∫ xmax {
}2
1
2
σf =
f2 (x) − cf1 (x) dx
xmax − xmin xmin

(14)

corresponds to a measure of the equality. The σ value depends on the normalization factor c:with

σf2 = ⟨f12 ⟩c2 − 2⟨f1 f2 ⟩c + ⟨f22 ⟩(15)∫ xmax {}21
f1 (x) dx,
xmax − xmin x∫min
xmax
1⟨f1 f2 ⟩ =f1 (x)f2 (x) dx, andxmax − xmin∫ xmin
xmax {}2
1⟨f22 ⟩ =f2 (x) dx.
xmax − xmin xmin

(16)

⟨f12 ⟩ =The minimum σf is provided when
∂σf2
= 0.
∂c

(17)

The optimum normalization to minimize σf2 is given byc=⟨f1 f2 ⟩,⟨f12 ⟩(18)

and the mimimum σf2 is ca;culated by
σf2 min = ⟨f22 ⟩ −⟨f1 f2 ⟩2.
⟨f12 ⟩(19)- 33 -

ELPH Annual Report, Tohoku University (2019)

When f1 (x) and f2 (x) have uncertainties δf1 (x) and δf2 (x), respectively, the minimum value ofχ2f , given byχ2f =∫ xmaxxmin{}2
f2 (x) − cf1 (x){}2 {}2 dx,
δf2 (x) + cδf1 (x)(20)

should be used instead of the minimum σf2 in Eq. (14). The normalization factor c is obtained from thecondition ∂χ2 /∂c = 0 in principle, but it requires complicated calculations. When f1 (x) does not havean uncertainty or δf1 (x) = 0 over the domain, n σf2

mincalculated in Eq. (19) can be used as a measureof the equality by replacing f1 (x) and f2 (x) with f1 (x)/δf2 (x) and f2 (x)/δf2 (x), respectively.

Acknowledgment
This work was supported in part by the Japan Society for the Promotion of Science (JSPS) throughGrants-in-Aid for Scientific Research (B) No. 19H01902, and for Scientific Research on Innovative Areas
Nos. 19H05141 and 19H05181.

References[1]

T. Ishikawa, Internal GeV-γ Analysis Note HD No. 437P (2020).

- 34 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2844, #2882, #2894, #2924)

Current status of the FOREST/BLC experiments at ELPH
T. Ishikawa1 , K. Aoki2 , H. Fujioka3 , Y. Honda1 , T. Hotta4 , K. Itahashi5 ,H. Kanda4 , H. Kawai6 , K. Maeda7 , Y. Matsumura1 , M. Miyabe1 , S. Miyata8 ,N. Muramatsu1 , H. Ohnishi1 , K. Ozawa2 , Y. Sada1 , H. Shimizu1 , M. Tabata6 ,A.O. Tokiyasu1 , and Y. Tsuchikawa9 for the FOREST/BLC collaboration
1

Research 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, Tokyo Institute of Technology, Tokyo 152-8551, 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

J-PARC Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, JapanThe FOREST/BLC experiments are conducted to determine low-energy S-wave ηn scattering parameters using the γd → pηn reaction. The photon beam with energies around 940 MeV can give therecoilless condition of produced η mesons by detecting the protons at 0◦ . The effects of the final-state
ηn interaction must be enhanced due to the small relative momentum between the η meson and theresidual neutron in this kinematics. In this year, the physics data were collected from April 8 to May
6 in 2019. In this report, a brief summary of the current status of the FOREST/BLC experiment andcollected data are described.

§ 1. Introduction
The nucleon resonance N (1535)S11 (N ∗ ) is an interesting object, which can be an S-wave ηNmolecule-like state and/or the chiral partner of the nucleon N . Recently, the internal structure of a
hadron has been intensively discussed in terms of the compositeness X, which is an overlap with thetwo-body scattering state [1]. The X can be given by the two-body low-energy scattering parameters for
the S-wave bound states and resonances in the threshold energy region [2]. The value of XηN = 0.04 +i0.37 fm obtained from the current knowledge of the ηN -scattering amplitude suggests a three-quark
state [3]. However, ηN scattering is not well known yet due to the difficulties in realizing scatteringexperiments because of the neutral and unstable nature of η (in general, it is difficult to obtain the lowenergy scattering parameters between a neutral meson and nucleon [4]). The reliability of the deducedXηN and corresponding structure of N ∗ remains questionable.

- 35 -

ELPH Annual Report, Tohoku University (2019)

The aηN values have been extracted by many theoretical analyses from the differential and total
cross sections for the πN → πN , πN → ηN , γN → πN , and γN → ηN reactions. Currently, theestimated aηN values are highly model dependent. While the values of Im[aηN ] are confined into a
narrow range from 0.2 to 0.3 fm, and those of Re[aηN ] are scattered in a wide range from 0.2 to 1.1
fm [8]. This uncertainty comes from the fact that the existing experimental data used for extractingaηN do not enhance the effect of the ηN -scattering (ηN → ηN ) amplitude. We propose the γd → ηpnreaction to determine aηN at a certain kinematics, which enhances the ηN scattering effect.
The incident photon bombards the quasi-free proton in the deuteron and produces a virtual η mesonwith a very low momentum. Events are selected in which the incident energy is approximately 0.94 GeV
and the proton is detected at 0◦ . The kinematics for these events satisfies the recoilless condition of the
produced η mesons. Thus, low-energy ηn scattering is expected to take place in this condition, where
the pn and ηp rescattering effects are suppressed owing to their large relative momenta (∼ 0.94 GeV).
The sensitivity to the Re[aηn ] and Re[rηn ] values are investigated and summarized in Ref. [7] by usinga model based on a dynamical coupled-channel meson-baryon scattering analysis [9, 10].

§ 2. Experimental setup
The γd → pηn reaction is measured at the Research Center for Electron Photon Science (ELPH),
Tohoku University, Japan [11] with the FOREST electromagnetic calorimeter system [12] together withan additional forward charged-particle spectrometer called BLC [13]. The incident photon energy ranges
from 0.82 to 1.26 GeV [15] for the circulating energy of 1.32 GeV in the electron synchrotron called thebooster storage (BST) ring [16]. The details of the FOREST detector including the liquid deuterium
target are described elsewhere [14]. The forward scattered proton is momentum-analyzed with the BLC
spectrometer behind FOREST. The trajectory of a charged particle is measured with 2 planar drift chambers (DCs), and the time of flight is measured with 14 plastic scintillator (PS) hodoscopes (PSH+). An
additional e/π separation is made using 10 SF5 lead-glass Cherenkov counters (LGCs). The experimental setup has been fixed since November in 2017. In this year, the physics data were collected in a period:
April 8 to May 6 (2019A) in 2019.
The BLC magnet was excited every time at normal operation in this fiscal year with a coil currentof 1400 A. The magnetic flux By at the center was monitored with a nuclear magnetic resonance (NMR)
probe during the experiments, and By = 716.0 mT was adjusted by changing the coil current. Fig. 1
shows the magnetic flux By at the center for the 2019A period.

§ 3. Collected data
The physics data with the deuterium and hydrogen targets were collected in the 2019A period. The
BST ring was operated with a circulating energy of 1.32 GeV, a current of approximately 20 mA. The datacollections were basically stable during the period. The injector linac suddenly died twice owing to thecurrent/voltage over at the beginning of the period. DC power supply modules became out of order threetimes for the septum magnet. The beam was recovered by replacing a module with a new one. Table 1- 36 -

Apr 08
Apr 09Apr 10
Apr 11
Apr 12
Apr 13
Apr 14
Apr 15
Apr 16
Apr 17
Apr 18Apr 19Apr 20
Apr 21
Apr 22
Apr 23
Apr 24
Apr 25
Apr 26
Apr 27
Apr 28Apr 29Apr 30
May 01
May 02
May 03
May 04
May 05
May 06

ELPH Annual Report, Tohoku University (2019)

716.2

B (mT)

716.1

716

715.9

715.8

715.7

0

5

10

15
time (day)20

25

Fig.1. Long-term variation of the magnetic flux at the BLC center measured with NMR in
2019A. The horizontal axis represents the number of days from 0:00am on April 08 in
2019, and the vertical shows the magnetic flux in mT. the red vertical lines correspondto the start timings of collecting the hydrogen, empty, and deuterium targets. The horizontal green lines show the ±0.001%、±0.01%、±0.02% variation from the set value of
716.00 mT.
summarizes the number of spills and events of the collected data in this fiscal year (2018). The statistics
for each of the hydrogen and deuterium data was 1.5 times higher than that for the 2009D period. The
data analysis is on-going to perform the precise energy and timing calibrations of the STB-Tagger II,
FOREST, and BLC detectors. The preliminary data are presented in Ref. [6].
Table 1. Numbers of spills and events collected in this fiscal year (2019). The circulating electronenergy of the BST ring was 1.3 GeV. The targets used were liquid hydrogen, deuterium,and empty.
period
2019Ahydrogen#spills#events
45.48 k 749.54 M

deuterium#spills#events
76.26 k 1, 388.36 M

empty#spills#events
8.96 k 121.26 M

Acknowledgment
The authors express gratitude to the ELPH accelerator staff for stable operation of the accelerators
for testing the AC detector. They acknowledge Mr. Ken’ichi Nanbu, and Mr. Ikuro Nagasawa for theirtechnical assistance. This work was supported in part by the Japan Society for the Promotion of Science(JSPS) through Grants-in-Aid for Scientific Research (B) No. 19H01902, and for Scientific Research on- 37 -

ELPH Annual Report, Tohoku University (2019)

Innovative Areas Nos. 19H05141 and 19H05181.

References[1]

S. Weinberg: Phys. Rev. 137 (1965) B672.

[2]

T. Hyodo: Phys. Rev. Lett. 111 (2013) 132002.

[3]

T. Sekihara, T. Arai, J. Yamagata-Sekihara, S. Yasui: Phys. Rev. C 93 (2016) 035204.

[4]

T. Ishikawa et al.: Phys. Rev. C 101 (2020) 052201 (R).

[5]

T. Ishikawa et al.: JPS Conf. Proc. 13 (2016) 020031.

[6]

T. Ishikawa et al.: Acta Phys. Polon. B 48 (2017) 1801.

[7]

S.X. Nakamura, H. Kamano, T. Ishikawa: Phys. Rev. C 96 (2017) 042201 (R).

[8]

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

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

[10] H. Kamano et al.: Phys. Rev. C 88 (2013) 035209.
[11] H. Hama: AAPPS Bulletin 30 (2020) 41.
[12] T. Ishikawa et al.: Phys. Lett. B 772 (2017) 398;
T. Ishikawa et al.: Phys. Lett. B 789 (2019) 413;
T. Ishikawa et al.: PoS (Hadron2013) 095;
Y. Tsuchikawa et al.: JPS Conf. Proc. 17 (2017) 062007;
T. Ishikawa et al.: PoS (INPC2016) 267.
[13] T. Ishikawa et al.: Acta. Phys. Polon. B 48 (2017) 1801;
T. Ishikawa et al.: JPS Conf. Proc. 10 (2016) 031001;
T. Ishikawa et al.: JPS Conf. Proc. 13 (2017) 020031;[14] T. Ishikawa et al.: Nucl. Instrum. Meth. A 832 (2016) 108.
[15] T. Ishikawa et al.: Nucl. Instrum. Meth. A 622 (2010) 1;
T. Ishikawa et al.: Nucl. Instrum. Meth. A 811 (2016) 124;
Y. Matsumura et al.: Nucl. Instrum. Meth. A 902 (2018) 103;
Y. Obara et al.: Nucl. Instrum. Meth. A 932 (2019) 108.
[16] F. Hinode et al.: J. Phys. Conf. Ser. 425 (2013) 072011.

- 38 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2925)

Study on the variation of efficiency and time resolution
depending on the electrode material of Resistive Plate
ChamberJ. Takahashi1 , H. Ohnishi1 , M. Miyabe1 , A. O. Tokiyasu1 , Y. Sada1 ,C. Yoshida1 , H. Saito1 , M. Turuta1 , R. Nishikawa1 , and T. Nobata1
1

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

We are developing a resistive plate chamber(RPC) for the E50 experiment at J-PARC [1]. The
electrode material used to supply HV on to the detector is not available on the market to date. Therefore,
it is mandatory to find a substitute for the electrode to construct next-generation RPC. We successfully
identified an electrode candidate and constructed an RPC by using the new electrode.
In this paper, we describe the results of the test experiments at the positron beamline of ELPH,
Tohoku University.

§ 1. Introduction
One of the hot topics in hadron physics is to reveal effective degrees of freedom (DoF) to describe
a hadron. These days, we believe there is a di-quark cluster that emerged as new degrees of freedom
in hadrons other than constituent quarks, which is expected to appear in baryons. However, it is quitedifficult to find it in a normal baryon. Because a mass of constituent quarks in a normal baryon isalmost equal, therefore it cannot be identified di-quark structure among those three constituent quarks
in a baryon.
The powerful and effective way to shed light on the cluster inside a baryon is, indeed, the spectroscopy of baryons which contained at least one heavy quark inside, e.g., charm or bottom quark. Oneof the important interactions between constituent quarks in hadron is color-magnetic interaction, whichis inversely proportional to the product of masses of two quarks. In the case of a baryon with one
heavy quark in it, such as a charmed baryon, the interaction between heavy quark-light quark gets tobe weakened relative to the interaction between light quarks because of the nature of color-magnetic
interaction. Thus cluster of two light quark structures will be enhanced effectively. Therefore uniquecharmed baryon mass spectrum in excited charmed baryon spectrum will be expected.
The J-PARC E50 experiment is focusing to reveal the di-quark cluster in charmed baryons. The
E50 experiment will measure both production cross-section and decay products of charmed baryon in
high-momentum pi-p reaction via missing-mass and invariant mass technique.
Figure1 shows a schematic view of the J-PARC E50 spectrometer system [2]. We are developing
the detector which is labeled as ”internal ToF Wall” in the figure. The main purpose of the detector is toseparate low-energy (∼1 GeV) π and K via a time-of-flight method. The time-resolution required for the- 39 -

ELPH Annual Report, Tohoku University (2019)

Fig.1. Spectrometer system of E50 experimentdetector is evaluated to be within 100 ps. In addition, the detector is placed inside the dipole magnet,
therefore the detector must work properly under the existence of a high magnetic field. Based on theconsideration above, we decided to construct the ToF detector by using the Resistive Plate Chamber
technique, which recently developed for a large volume with a high timing-resolution ToF detector.

§ 2. Resistive Plate Chamber (RPC)
RPC is a gas-based detector that mainly used for a Time of Flight (ToF) measurement. The typicalstructure is shown in Fig.2. Fig.2(Left) shows a single stuck structure and Fig.2(Right) shows a double
stuck structure of RPC. The single stuck detector is relatively easy to construct, however, the double
stuck detector shows good timing and efficiency performance. Because the signal readout from thecentral read-out(R/O) pad is summed up signals of the top and bottom part of the detector. Therefore,
the signal of the detector is nearly doubled compared with a single stack structure.
We constructed RPCs for ToF measurement for LEPS2 experiment at SPring-8 [3]. Based on thisexperience, we decide to construct RPCs for the E50 experiment. However, one problem raised. We
used the high-resistance tape for the electrode to supply High voltage to the detector. For LEPS2-RPC,
we used the carbon-tape called T-9145 from ESD EMI Engineering Co., Ltd., [4]. Unfortunatelly, thetape is no longer available on the market. Therefore we need to find a substitute for the tape used for
LPES2-RPC to construct new RPCs for the E50 experiment.

§ 3. Resistive Tape
The tape used for the electrodes of the RPC must be high resistance. If the resistance of electrodes
is low, the signal generated by RPC will be diffused. This increases the rate of crosstalk and reduces the
charge on the output signal. On the other hand, if the resistance is too high, the rate tolerance will be
partially reduced. Table.1 shows a list of high-resistance tape that has actually been used to constructprototype RPC and tested with cosmic rays. Fig.3 shows RPCs made using these tapes. As a result of
the cosmic ray test, detectors constructed with low resistivity tapes were noisy, and the signal could not
be seen. Only one candidate remained with the cosmic ray test. That is MK-APT of Tanimura Co., Ltd.,- 40 -

ELPH Annual Report, Tohoku University (2019)

Fig.2. The typical structure of RPC. The left is called single-stack RPC and the right is called
double-stack RPC. Double-stack is a structure in which two single-stack are stacked.

[5]. For the detailed investigation, we decided to perform the RPC beam test by using MK-APT as ahigh-voltage electrode of the detector.

Tape
T-9145
ASB-110
ASB-121
MK-APT
TW-CPT
SDT1005

Resistance [Ω]
1.5 × 107
1.3 × 104
7.5 × 103
2.0 × 108
6.2 × 105
6.0 × 103

Price [JPY/m]
10000
13000
8800
1000
500
6000

SignalCan see
Noisy
Noisy
Can seeCan’t see
Noisy

Table. 1. Listofhigh-resistancetapes used for RPC
Fig.3. Puroduced RPC§ 4. Test Experiment with positron beam at GeV-γ experimental hall
The test experiment is performed with a positron beam at the GeV-γ experimental hall. The γ-ray
from the BST ring is converted to the electron-positron pairs in the 200 µm-thick tungsten installedin front of the Tag-X magnet. The converted positrons’ momentum is selected by Tag-X magnet andtransported to the test experimental area. The experimental setup is shown in Fig.3. The momentumof the positrons used in the test experiment was 671 MeV/c. The positron’s typical intensity is about
2000 Hz with 60x60/cm2 , a covered region of trigger counters, Trigger1, and Trigger2. The test detector
is installed as a first detector of the setup to eliminate the beam position’s energy loss and multiplescattering. Two first scintillator counters, which required H2431 PMTs on both end, are installed justafter the Trigger1 to generate the system’s reference timing.
We tested three single-stack RPCs and a double-stack RPC using ordinally carbon tape, i.e., T-9145,
and two single-stack RPCs using MK-APT.

- 41 -

ELPH Annual Report, Tohoku University (2019)

Fig.4. Schematic view (left) and photo (right) of experimental setup§ 5. Results and Discussion
Fig.5 shows detector efficiency as a function of the applied voltage. Three blue curves show theresults from a single stack detector with T-9145. The blue curve shows results from the double stuck
detector with T9145. The red one is the results of a single stuck detector with MK-APT. The efficiency
for all RPCs has reached a plateau, ∼90 % when the applied voltage is 16 kV. However, it is instantly
noticed that the detector constructed with MK-APT needs to apply ∼13% more high-voltage to reachefficiency plateau.
In this test, we construct two single stuck RPCs with MK-APT. One RPC is properly working during
the beam test, which is shown in the Fig5. However, the other one never worked. A detailed investigation
to find the difference between those two has been performed, and finally, we found that the resistanceof MK-APT changed during the production process of RPC. Therefore, we need further study on theproperties of MK-APT itself and optimize the production process.

Fig.5. Detector efficiency as a function of applied voltage.

Next, we will evaluate the time resolution of detectors. Since the signal charge output from singlestack RPC was small, the time resolution could not be evaluated. Therefore, we will only evaluate thetime resolution for double-stack RPC. The time resolution of RPC is derived using three detectors, Refference1, Refference2, and RPC. Fig.6 shows the distribution of the time difference between Refference1
and RPC vs. output charge of the RPC(ADC). The time-resolution is evaluated after time-work correction(slewing correction), shown as the most right figure in Fig.6. The time difference between eachdetector after slewing correction are shown in Fig.7. The intrinsic time resolution of the RPC derived- 42 -

ELPH Annual Report, Tohoku University (2019)

Fig.6. Distribution of the time difference between Refference1 and RPC vs. ADC of the RPC,
and state of slewing correction.

Fig.7. Time difference after slewing correction of Refference1 and RPC (left), Refference2 andRPC (center), Refference1 and Refference2 (right).

from Fig.7 was 88 ps.It turns out that the experimental system can measure a time resolution of 90 ps.
Immediately in the future, we will manufacture a double-stuck RPC using MK-APT and measure thetime resolution.

§ 6. Summury
We are developing a resistive plate chamber(RPC) for the E50 experiment at J-PARC. The electrodematerial used to supply HV on to the detector is not available on the market to date. Thus, we need tosearch for high-resistance tapes that can be used for RPC electrodes. After the evaluation process withcosmic ray, we found one promising candidate, which can be used for RPC production. The performance
test experiment has been performed at the ELPH GeV-gamma beamline. On the test experiment, wewere comparing the detector performance with the detector constructed with the ordinal electrode (T9145) and with the new candidate MK-APT. The detection efficiency of RPC using MK-APT reached
90 % at the applied voltage of 16 kV. However, we need 13% more HV need to supply to the detector with
MK-APT. Time resolution of RPC using MK-APT could not be measured. In the future, we will make adouble-stuck RPC using MK-APT and compare it with the time resolution.of that using T-9145.

- 43 -

ELPH Annual Report, Tohoku University (2019)

Acknowledgments
We are grateful to the all staff members of ELPH for their extensive efforts on the successful operation of the facility. This work is partly supported by the MEXT Grants-in-Aid for Sientific Researchon Innovative Areas ”Clustering as a window on the hierarchical structure of quantum systema” GroupA02(18H05402).

References[1]

J-PARC E50 proposal, see http://j-parc.jp/reseacher/Hadron/en/Proposal e.html[2]

Y.Komatsu JPS Conf. Proc. 26(2019) 022029[3]

K. Watanabe et al. Nucl. Instrum. Meth. A 925(2019)188[4]

https://www.esd-emi.com[5]

https://www.tanimura.biz/catalog/antistatic cl pettape.html- 44 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2926)

Performance Evaluations of Resistive Plate Chamber with
R1234ze as eco-friendly gas
Ryota NISHIKAWA1∗ , Kazuya NOBATA1∗ , Junpei TAKAHASHI1∗ ,and Hiroaki OHNISHI1∗
1

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

Resistive Plate Chamber (RPC) is one of the most popular detectors for Time-of-flight measurement.
However, the gas used for the detectors is known to have high global warming power. Thus we need tofind a substitute with a more eco-friendly one. One of the candidates is the gas called R1234ze, whichhas ∼ thousand times lower global warming power than R134a. In this report, the RPC performance
evaluation results with R1234ze gas will be presented instead of R134a.

§ 1. Introduction
Resistive Plate Chamber (RPC) is one of the most attractive technologies for Time-of-Flight (TOF)
measurement. These days, many nuclear and high energy physics experiments used RPC as their ToF
detector for three reasons as follows. First of all, RPC has a good time resolution of about 50 ps and close
to 100% detection efficiency. Second, the large size of the detector can easily be constructed at a low cost.
Lastly, the detector works perfectly under a high magnetic field environment.

readout pad

insulator
electroderesistive plate
spacer

Fig.1. The schematic view of the multi-gap RPC

Figure 1 shows a schematic view of the RPC structure. The detector was composed of multiple
resistive plates, which kept a gap between plates by spacers. The typical size of the gap is an order of afew hundred µm. We are using the fishing line as a spacer. Gaps are filled with detector gas, a mixture∗

Present address: Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826- 45 -

ELPH Annual Report, Tohoku University (2019)of R134a(1,1,1,2-Tetrauoroethane/CH2FCF3), iso-C4H10, and SF6. This gas mixture is commonly used
as a detector gas worldwide. The high voltage is applied to electrodes, which are placed most outside of
the resistive plate. The electric field generated by the applied high voltage is reached as ∼10 kV/mm.
Once a charged particle passes through the detector, the gas between the gap will be ionized and start
to instantly multiplicate electrons due to the high electric field. Soon after, developed electric signals
are induced to the readout pad placed most outside of the detector. There are two types of operation
modes. One is a streamer mode, which makes a large signal. We expect to have high detection efficiency
in this operation mode. However, only poor timing resolution is obtained,i.e., ∼1 ns. This operation
mode is suitable for the RPC used as a trigger counter. The other operation mode is the avalanche mode
operation. In this operation mode, a good time resolution of the detector is achievable, i.e., ∼50 ps.
However, the signal generated from the detector is so small. Thus a high-performance pre-amplifier isneeded to be equipped on the detector.
Global warming is one of the most serious problems for human beings. To reduce the warming speedon earth, the reduction of global warming gas usage is agreed international wide. The Global Warming
Potential (GWP) is an indicator to evaluate the badness of the gas used, which is normalized with thewarming power of CO2. The gas mixture of ( R134a : iC4H10 : SF6 = 90 : 5 : 5. ) are used widely for
RPC. GWP of this gas mixture is estimated to be 2,427. Thus, nowadays, gas using for RPC is indeed
categorized as a global warming gas. RPC operation with non- or less GWP gas mixture is one of thegreat challenges for RPC development.
Recently, R1234ze (trans-1,3,3,3-Tetrauoropropene/C2H2FCF3) has been used as a replacement for
R134a, which is widely used for refrigerant of an air conditioner. The GWP of R1234ze is expected tobe 1. Therefore, we may have a chance to operate RPC with low GWP gas by changing RPC’s main gas
from R134a to R1234ze.
This report will present the difference in RPC performance by changing the mixture of gas content.

§ 2. Gas mixture
The GWP of the gas with a different mixture of content and fraction is summarized in Table1. Incase if we replaced R134a with R1234ze, we could reduce the GWP by half.
Table. 1. Mixture rate and GWP
R134a:iC4 H10 :SF6 (GWP) R1234ze:iC4 H10 :SF6 (GWP)
90:5:5 (2,427)
90:5:5 (1,141)
95:5:0 (1,359)
95:5:0 (1)90:10:0 (1,287)
90:10:0 (1)80:20:0 (1,145)
80:20:0 (2)95:0:5 (1,141)- 46 -

ELPH Annual Report, Tohoku University (2019)§ 3. RPC used for the test experiment
For this experiment, RPC with five gaps has been constructed. To make gaps, the fishing line isused as a spacer, whose diameter is 0.260mm. As resistive plates, thin glass plates are used. The size ofa glass plate is 100mmx100mmx0.4mm. On both sides of RPC, 3 readout pads are placed, whose size is
20mm×80mm.

§ 4. Test setup
The test experiment is performed with a positron beam at Gev-gamma experimental hall. Bremsstrahlung
gamma-ray is delivered to the Gev-gamma experimental hall, and converted to electron-positron pair bya thin metal foil as a converter. A positron with a momentum of 600 MeV/c has been selected via Tag-X
magnet and delivered to the positron beamline. Figure 2 shows a schematic view of the test experiment
setup. The beam first hit on the test detector, and events are triggered by the coincidence signal fromtwo scintillator counters, i.e., Trig1 and Trig2. The signal from Trig3, which is a very narrow scintillator
counter, is used offline analysis to ensure the positron hit on a readout pad on RPC.

Fig.2. The schimatic view of the test experimental setup§ 5. Result and discussion
Figure 3 shows a typical crrelation between pulse hight and timing measurement by the test chamber with a standard gas mixture. The difference between the left and the right figure is its applied highvoltage to the chamber. Once we increase applied voltage, the single cluster distribution which is shownin the left figure split into two parts. The one which has lower ADC is understood as a signal fromavalanche mode operation. The other one which has high ADC value is from streamer mode operation.
For the ToF detector, we need to minimize the fraction of the event detected with the streamer mode
operation. Thus, we defined the streamer fraction as a number of events generated via streamer mode
operation, with respect to the total number of events.

- 47 -

ELPH Annual Report, Tohoku University (2019)

Fig.3. Correlation plot between ADC and TDC

The definition of efficiency(Eff) is as follows.
Eff =T rig1 ⊗ T rig2 ⊗ T rig3 ⊗ RP C(withTDC valid hit)
T rig1 ⊗ T rig2 ⊗ T rig3

(1)

Where RP C(withTDC valid hit) is that TDC value is not overflowed, i.e., TDC ̸= 4095.
Figure 4 shows detector efficiency(shown as a solid circle) and streamer fraction(shown as a solid
diamond) as a function of the applied high voltage by using R134a as a based gas. The efficiency reachedmore than 95% when we applied more than 13.5 kV to the detector. For the case of R134a based gas,efficiency is not sensitive by changing mixed fraction for other gases. The streamer fraction is at most
10% with the high voltage ∼ 17 kV. On the other hand, if the detector operated with R1234ze based gas,
both efficiency and streamer fraction are susceptible by changing the gas mixture fraction. Moreover,detector efficiency does not reach the efficiency plateau with H.V. =17 kV, which is the maximum voltage
we can apply for this test experiment. One of the reasons why the efficiency of the R1234ze based
operation is lower than R341a based operation is that the produced charge is smaller in R1234ze than
R134a. Need more study about the signal charge depending on the gas mixture. R1234ze based gas canbe used as a detector gas, however, we need to apply at least about 30% more H.V. than R134a based gas
detector. Further studies are needed to make a solid conclusion.
Figure 5 shows the efficiency of the detector operation with R1234ze based gas. The left side isadding only 5% of iC4H10, and the right is adding 5% SF6. For the gas with 5% iC4H10, we repeatedmeasurement three times and got almost consistent results. The situation is also the same for the gas
with 5% SF6. It is interesting to note that the gas with 5% iC4H10 shows higher efficiency than the gas
with 5% SF6. The difference can be interpreted as the produced signals can be quenched by SF6 morethan iC4H10.

§ 6. Summury
To date, RPC is known to be a commonly used detector for Time-of-flight measurement. However,
because the gas used for RPC is categolized as Global warming gas, detector gas for RPC need to be
replaced by concerning on the global warming.
We tested RPC operation with an eco-friendly gas mixture and found promising results. The detec-- 48 -

ELPH Annual Report, Tohoku University (2019)

Fig.4. Efficiency Streamer Fraction curve by changing applied HV

Fig.5. Efficiency Streamer Fraction curve by changing applied HV

tor shows close to 90% efficiency with the best gas mix fraction ( R1234ze: iC4H10: SF6 = 90: 5: 5. )with H.V.=17kV. However, the efficiency curve shows that the efficiency did not seem to get in the maximum plateau region. Moreover, the H.V. 17 kV is about 30% higher H.V. than that of R134a operation.
Besides, the time resolution for the detector is not tested. Further studies are needed to make a solid
conclusion.

Acknowledgment
We are grateful to the all staff members of ELPH for their extensive efforts on the successful operation of the facility. This work is partly supported by the MEXT Grants-in-Aid for Scientific Research on
Innovative Areas “Clustering as a window on the hierarchical structure of quantum systems” Group-A02(18H05402).

- 49 -

ELPH Annual Report, Tohoku University (2019)

References[1]https://www.jccca.org/chart/chart01 02.html[2]https://www.jsrae.or.jp/committee/jisedai R/H30 ProgressR WG3.pdf[3]http://www.mihama.com/products/refri/r1234ze.html- 50 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2916, #2927)

The performance study of the aerogel Cherenkov counterfor the LEPS2-solenoid experiment
C. Yoshida1 , A.O. Tokiyasu1 , H. Ohnishi1 , T. Ishikawa1 , M. Miyabe1 ,H. Saito1 , J. Takahashi1 , and M. Tsuruta1
1

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

We have developed an aerogel Cherenkov counter (AC), which separate a pion and a kaon in the
momentum region 1 - 2 GeV/c, for the hadron photoproduction experiment at SPring-8. We measured
the reflector dependence and the incident position dependence using a positron beam and estimated thepion detection efficiency and kaon misidentification (misID) probability. We decided to use aluminized
mylar for the AC reflector and determined the final design of the AC.

§ 1. Introduction
We plan to perform the hadron photoproduction experiment at the LEPS2 beamline in SPring-8.
The aim of this experiment is to investigate the mechanism of the exotic hadrons, such as penta-quark
Θ+ , Λ(1405), the K − pp bound state. Aerogel Cherenkov counter (AC) is one of the key detectors of the
LEPS2 solenoid system, and distinguish kaon and pion with high momentum larger than 1 GeV/c. The
requirements of AC are as follows.
• to cover the region within a polar angle between 30 to 40 degrees with respect to the beam direction.
• to have pion detection efficiency more than 95%• to be installed in narrow space ( ∼ 10 cm)• to be operated in the magnetic field ( ∼ 1 T)
• the material budget should be minimized
Considering these requirements above, we designed the prototype detector using aerogel which refractive index is 1.03 as a radiator. For the photon detector, we will use 3 inch fine-mesh Photomultiplier
Tube (PMT) to ensure good photon detection performance under the high magnetic field. For the reflector inside the counter, we have multiple choices, i.e., Enhanced Specular Reflector (ESR) or Aluminized mylar. We evaluated the reflector dependence of the pion detection efficiency (efficiency) andkaon misidentification probablity (misID) of the prototype at the #2916 experiment. We constructed 3
type of AC boxes (box1 : ESR, box2 : Aluminized mylar & ESR, box3 : Aluminized mylar) and compared
their efficiency and misID. The final version of the detector is shown in Fig.1. At the #2927 experiment,
we evaluated the incident position dependence of efficiency and misID precisely. In this report, we show
the results of these two test experiments.

- 51 -

ELPH Annual Report, Tohoku University (2019)

Fig.1. Cross section view of the AC§ 2. Experimental Setup
The test experiments #2916 and #2927 were performed at the 30-degree positron beamline in the
GeV-γ experimental hall. The setup is shown in Fig.2. 600 MeV positron was used for these experiments.
Trigger 1 and Trigger 2 are plastic scintillators. Those size was 10 × 50 × 5 × mm (width × height ×thickness). They were installed upstream and downstream of AC, respectively. Trigger signal for datataking was produced with the coincidence signal of Trigger1 and Trigger2. We measured the Cherenkov
light signal detected with PMT by changing the beam hit position on the AC to study the incident beam
position dependence on its performance.

Fig.2. Top view of the setup§ 3. Results
3.1 ELPH experiment : #2916
Fig.3 shows the typical charge distribution from the AC when the beam hit on 200 mm from the edgeof the AC box. The efficiency and misID probability have been evaluated from the charge distribution of
the AC with and without the Cherenkov radiator. The definition of efficiency and misID are as follows.

- 52 -

ELPH Annual Report, Tohoku University (2019)

Fig.3. Charge distribution when Aluminized mylar box with incident position 200 mm from theedge of the AC box. Red line is that with aerogel and blue line is that without aerogel.

Counts (ADC ch > threshold)Counts (Trigger)
Counts (ADC ch > threshold)misID (w/o aerogel in the AC box) =Counts (Trigger)

efficiency (w/ aerogel in the AC box) =The threshold value of the above evaluation has determined where the efficiency of the detector
exceeds more than 95% at the beam hit position more than 50 mm from the AC box’s edge for each AC
box. The threshold values in ADC ch are 42 ch, 22 ch and 4 ch for box1, box2 and box, respectively. The
incident position dependence of efficiency (red line) and misID (blue line) for each AC are shown in Fig.4.
According to Fig.4, the highest misID values are 41%, 12% and 10% for box1, box2 and box3 respectively.
From these results, we decided to use aluminized mylar for the AC reflector.

Fig.4. The incident position dependence of efficiency (red line) and misID (blue line) for (a) box1,(b) box2 and (c) box3.

3.2 ELPH experiment : #2927
We evaluated the efficiency and misID of the final version AC box in the same way to #2916. The
incident position dependence of efficiency (red dot) and misID (blue dot) are shown in Fig.5. We foundthat the requirements are satisfied when an incident position is larger than 100 mm.

- 53 -

ELPH Annual Report, Tohoku University (2019)

Fig.5. The incident position dependence of efficiency (red dot) and misID (blue dot).

§ 4. Summary
We evaluated the performance of the aerogel Cherenkov counter (AC) for LEPS2 experiment. At thetest experiment #2916, we estimated the reflector dependence of the pion detection efficiency and kaon
misID probability. As a result, aluminized mylar is adopted as a reflector for AC. The detector performance with the final configuration had been performed as #2927. In this test experiment, the incident
position dependence of the detector was evaluated. We found that the requirements are satisfied when
an incident position is larger than 100 mm. Based on the series of experimental results, construction of
the AC detectors for LEPS2 was underway.

Acknowledgment
We are grateful to the all staff members of ELPH for their extensive efforts on the successful operation of the facility. This work is partly supported by the MEXT Grants-in-Aid for Scientific Researchon Innovative Areas ”Clustering as a window on the hierarchical structure of quantum system” GroupA02(18H05402).

- 54 -

ELPH Annual Report, Tohoku University (2019)

Status of LEPS2-solenoid experiment in 2019
Atsushi Tokiyasu1 , Yuta Sada1 , and LEPS2 collaboration
1

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

The LEPS2-solenoid experiment at SPring-8 is aiming to investigate the hadron photoproduction
mechanism. LEPS2 spectrometer system is under preparation; Detectors and data acquisition system
are developed, and the performance check of each detector is on-going. In 2019, some new detectors were
installed in the spectrometer, and the data with nuclear target was taken for the purpose of the detector
calibration. We plan to continue the calibration of the detectors by using the liquid hydrogen target in
FY2020.

§ 1. Overview of LEPS2-solenoid experiment
The LEPS2-solenoid experiment is aiming to study the hadron photoproduction mechanism at
SPring-8. A high intensity γ beam by Backward Compton Scattering is used to search for exotic hadronsystems like penta-quark Θ+ , the K − pp bound state, and so on. In addtion, we will investigate theproduction mechanism of hadrons precisely. We constructed LEPS2 spectrometer system to detect theparticles produced from the target. The overview of the LEPS2 spectrometer system is shown in Fig.
1. The LEPS2 spectrometer system is composed of Start Counter(SC), Time Projection Chamber(TPC),
Drift Chambers(DCs), Aerogel Cherenkov Counter (AC1, AC2), Resistive Plate Chamber (RPC), andBarrel-γ. These detectors are installed inside solenoid magnet with the strength of 1T, and used todetect both of charged particles and γs from the hadron reactions.

§ 2. Progress in FY2019
Following the previous year, we continued taking the data for the detector calibration by using a
nuclear target made of copper or polyethylene . One of the main progresses in FY2019 is the success atreading all 6 sectors of TPC. We took the calibration data. The tracks were reconstructed, the postion
resolution and the drift speed were obtained. The drift speed of TPC was found to be 50 % of nominal
value. We investigaed the reson, and found the problem in the drift cage. The broken part of TPC will
be repaired, and the calibration data will be taken ealry in FY2020.
In addition, we installed three new detectors in the spectrometer system; Start Counter (Fig. 2-(a)), Barrel RPC (Fig. 2-(b) ), Barrel γ (Fig. 2-(b) ), 4 th Drift Chamber (Fig. 2-(d) ), Aerogel Cherenkov
Counter (Fig. 2-(e) ), We evaluated the performance of the newly installed detectors. As for the start
counter, the time resolution was measured to be approximately 150 ps. This value is enough to separate
the RF siganals which are used as the start timing (Fig.3). These results were reported in 75 th JPS- 55 -

ELPH Annual Report, Tohoku University (2019)

Fig.1. LEPS2 spectrometer system

Fig.2. Pictures of newly installed detectors- 56 -

ELPH Annual Report, Tohoku University (2019)

meeting [1]. As for the Barrel-γ, we prepared the 2nd layer of the calorimeter of 4 layers in total. The

Fig.3. RF signals measured by Start Counter
radiation length is 6.48X0 . 96 photomultipliers were attached to the end of the calorimenter. The charge
information and timing information of the signals were taken together with other detectors of the LEPS2
spectormeter system. The occupancy plots for each layers are shown in Fig. 4. Some channels were foundto be broken. Replacement of photomultipliers are on-going. After this work, we will perform the gain
tuning for each photmultiplier. The performance of Aerogel Cherenkov Counter was checked by using

Fig.4. Occupancy plots for Barrel-γ
positron beam at ELPH (Exp No. 2916, 2927). The design was ﬁxed, and three modules were installedin the LEPS2 spectrometer system. The callibration data was taken and the coincidence analysis withother detectors are on-going to evaluate the pariticle identiﬁcation potential .

§ 3. Transmission measurement
We measured the transmission of photon-beam at LEPS2 in autumn in 2019. The setup is shownin Fig.5. From upstrteam, an upveto counter to reject the beam halo, a converter to produce e+ e- pair, astart counter to produce the data taking trigger, the beam proﬁle monitor and a Lead Glass calorimeter
to measure the photon energy were installed on the LEPS2 beam line. By taking ratio between the- 57 -

ELPH Annual Report, Tohoku University (2019)

counts of tagger signal and the Lead glass, the value of transmission was obtained. The measured valueof transmission is approximately 75 %, which is consistent with the caluclated values. In addition tothat, we found that the energy dependance of transmission appear unless the expander condtions are
optimized. The simpler detector system is under construction, and will be installed upstream the beam
dump in FY2020. This system will be used to check the long-term stability of the photon beam during
taking the physics data. These results were reported in the 75 th JPS meeting [3].

Fig.5. Setup for the transmission measurement
Fig.6. Transmission v.s. Photon Energy§ 4. Plans for FY 2020
We will install all main detectors and prepare the data acquisition system in the spectrometer in
FY2020. The detector calibration run is shceduled by using liquid hydrogen target. For the stable dataacquisition, we develop the beam monitor system now. It will also be installed in FY2020. After taking
data for the detector calibration, we start taking physics data.

References[1]

R. Mizuta et al.: “Paformance study of trigger counter for LEPS2 spectrometer at SPring-8 ”, JPS
Meeting, 19th Mar. 2020, Nagoya Univ.

[2]

C. Yoshida et al.: “Development of an aerogel Cherenkov counter for the LEPS2 solenoid experiment at SPring-8”, JPS Meeting, 9th Sep. 2019, Yamagata Univ.

[3]

H. Saito et al.: “Measurement of the transmission at the LEPS2 beamline”, JPS Meeting, 19th
Mar. 2020, Nagoya Univ.

- 58 -

ELPH Annual Report, Tohoku University (2019)

Studies for nuclear medium modiﬁcation of the η ′ meson
mass at the SPring-8 BGOegg experimentN. Muramatsu1 , N. Tomida2 , Y. Matsumura2 , J.K. Ahn3 , W.C. Chang4 ,J.Y. Chen5 , M.L. Chu4 , S. Daté2 , T. Gogami6 , H. Goto2 , H. Hamano2 ,T. Hashimoto2 , Q.H. He7 , K. Hicks8 , T. Hiraiwa9 , Y. Honda1 , T. Hotta2 ,H. Ikuno2 , Y. Inoue1 , T. Ishikawa1 , I. Jaegle10 , J.M. Jo3 , Y. Kasamatsu2 ,H. Katsuragawa2 , S. Kido1 , Y. Kon2 , T. Maruyama11 , S. Masumoto12 ,K. Miki13 , M. Miyabe1 , K. Mizutani10 , H. Nagahiro14,2 , T. Nakamura13 ,T. Nakano2 , T. Nam2 , T.N.T. Ngan15 , M. Niiyama16 , Y. Nozawa17 , Y. Ohashi2 ,H. Ohkuma2 , H. Ohnishi1 , T. Ohta17 , M. Oka2 , M. Okabe1 , K. Ozawa18 ,C. Rangacharyulu19 , S.Y. Ryu2 , Y. Sada1 , T. Shibukawa12 , H. Shimizu1 ,R. Shirai1 , K. Shiraishi1 , E.A. Strokovsky20,2 , Y. Sugaya2 , M. Sumihama13,2 ,S. Suzuki21 , S. Tanaka2 , Y. Taniguchi1 , A. Tokiyasu1 , Y. Tsuchikawa22 ,T. Ueda1 , H. Yamazaki23 , R. Yamazaki1 , Y. Yanai2 , T. Yorita2 , C. Yoshida1 ,and M. Yosoi2
1

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

Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan3

Department of Physics, Korea University, Seoul 02841, Republic of Korea
4

5

6
7

Institute of Physics, Academia Sinica, Taipei 11529, Taiwan

National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
Department of Physics, Kyoto University, Kyoto 606-8502, Japan

Department of Nuclear Science & Engineering, College of Material Science and Technology, Nanjing University of
Aeronautics and Astronautics, Nanjing 210016, China
8

Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA
9

10
11

College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-8510, Japan
12

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

13
14
15

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

Department of Physics, Nara Women’s University, Nara 630-8506, Japan

Nuclear Physics Department, University of Science, Vietnam National University, Ho Chi Minh City, Vietnam
16
17

18

RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan

Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA

Department of Physics, Kyoto Sangyo University, Kyoto 603-8555, Japan

Department of Radiology, The University of Tokyo Hospital, Tokyo 113-8655, Japan

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

19
20

Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada

Laboratory of High Energy Physics, Joint Institute for Nuclear Research, Dubna, Moscow Region, 142281, Russia
21Japan Synchrotron Radiation Research Institute (SPring-8), Sayo, Hyogo 679-5198, Japan
22

23

J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan

Radiation Science Center, High Energy Accelerator Research Organization (KEK), Tokai, Ibaraki 319-1195, Japan- 59 -

ELPH Annual Report, Tohoku University (2019)§ 1. Introduction
The BGOegg experiment, studying the nature of hadrons through the photoproduction of them, iscarried out at the SPring-8 LEPS2 beamline, where a linearly polarized photon beam is available in theenergy range of 1.3 − 2.4 GeV. We have constructed a large acceptance electromagnetic calorimeter,
called “BGOegg”, and set it up with several charged-particle detectors at the LEPS2 experimental building. The BGOegg calorimeter covers a polar angle range from 24◦ to 144◦ with 1320 Bi4 Ge3 O12 (BGO)
crystals, providing the world-best energy resolution of 1.3% for a 1-GeV γ ray. In the experimental programs using a liquid hydrogen target, excited baryon resonances are searched for in the s-channel ofneutral-meson photoproduction processes. So far, differential cross sections and photon beam asymmetries have been measured for the photoproduction of π 0 , η, and ω mesons, which ﬁnally decay into a few
γ’s [1, 2].
As main physics programs of the BGOegg experiment, we also study nuclear medium modiﬁcation ofthe η ′ -meson mass by using a 20-mm-thick carbon target. Spontaneous breaking of the chiral symmetry
is considered to be partially restored at the nuclear density, and an η ′ mass reduction of 40 − 150 MeV ispredicted by several hadron models with effective QCD Lagrangians [3–5]. In order to search for signalsof the η ′ mass reduction, we have proceeded with two independent analyses: In one method, nuclear
bound states of η ′ mesons have been searched for by a missing mass spectroscopy with forward highmomentum protons. If the reduction of the η ′ mass is large inside a nucleus, such a bound state can beformed with a large optical potential. In contrast, the other analysis has performed direct measurementof a γγ invariant mass spectrum from the η ′ decays inside a nucleus. This method is sensitive to thecase of a smaller mass reduction.

§ 2. Search for η ′ bound nuclei
The search for the η ′ bound nuclei was conducted in the 12 C(γ, p) reaction by detecting a forward
proton at the resistive plate chamber (RPC) wall, which was located 12.5 m downstream of the carbon
target with a polar angle coverage up to 6.8◦ [6]. The time-of-ﬂight of a charged track was measured
with a time resolution of 60 − 90 ps, and translated to a momentum by assuming the detected track
should be a proton. If η ′ bound signals exist, they must appear below the production threshold in the
proton missing mass spectrum. Because there remain a lot of background events in such a spectrum, the
BGOegg experiment has, for the ﬁrst time, required the simultaneous detection of conversion signals bybound η ′ mesons and nucleons (N ’s), namely the reaction η ′ N → ηN , followed by the η → γγ decay.
Black dots in Fig. 1 show the excitation energies Eex − E0 (missing masses relative to the η ′ production threshold) and η emission angles cos(η) (polar angles in the Lab frame) of the real data events after
requiring the dection of an η meson, decaying into γγ, and a slow proton (ps ) at the BGOegg calorimeter. Unfortunately, this sample was still dominated by backgrounds mainly due to the η photoproduction,
where the secondary interactions of primary products made additional slow protons. Therefore, we further developed kinematical cuts by requiring the back-to-back nature of the η and ps pair, omitting
boosted events with very forward production of either η or ps , and so on. Here the cut conditions were

- 60 -

ELPH Annual Report, Tohoku University (2019)

Fig.1. A two-dimensional plot of the η polar angle versus the excitation energy for signal samples of the η ′ bound nuclei search [7]. The red shaded area indicates a signal searchregion.

optimized without examining the predetermined signal region, indicated by a red shaded area in Fig. 1.
Finally, only events shown by blue circles survived after applying the kinematical cuts, and no eventswere observed in the signal region. Based on this fact, we determined an upper limit for the production of η ′ bound nuclei with an η-ps pair to be 2.2 nb/sr (90% conﬁdence level) at the opening angles
cos(ηps ) < −0.9.
We comapared this upper limit of the production cross section with a theoretical calculation using
distorted wave impulse approximation (DWIA) and assumption of a few optical-potential values [8]. In
the process of the comparison, we normalized the theoretical calculation by using the observed amount ofquasi-free η ′ photoproduction events. This was essential to remove ambiguities in the DWIA calculation.
As a result, we have obtained an indication that a large optical potential (V0 ) is not favored because abranching fraction of the one-nucleon absorption process (the η ′ N → ηN conversion) is unnaturally
limited below 24% in the case of V0 = −100 MeV.

§ 3. Direct measurement of the η ′ mass spectrum
In the BGOegg experiment, an alternative analysis method to obtain a hint of the η ′ -mass reduction
at the nuclear density was also adopted by measuring a distibution of γγ invariant masses (Mγγ ’s),
calculated from the energies and hit positions of two γ-rays at the BGOegg calorimeter [9]. A γ-ray
hit was reconstructed by clustering neighboring BGO crystals with energy deposit and by conﬁrming nocharge hit at a corresponding inner hodoscope. Overlap of two particle hits in a reconstructed cluster
was identiﬁed based on the properties related to a cluster shape and shower-energy distribution. No hits
except for the two γ-rays and a charged track, which may be a proton, were allowed to select the ﬁnal

- 61 -

ELPH Annual Report, Tohoku University (2019)

Fig.2. A spectrum of γγ invariant mass for the momentum range below 1 GeV/c in the carbon
target data [10]. Background functions are ﬁtted by using the data points outside thevertical blue lines.
sample.
Figure 2 shows a preliminary result of the γγ invariant mass spectrum in the case that the momentum of a γγ system is required to be lower than 1 GeV/c. This condition was introduced to increasea fraction of the decays inside a nucleus, and determined by a simulation so that a statistical significance of possible signals should be most enhanced. Background functions to be ﬁtted were prepared
for the photoproduction processes of quasi-free η ′ mesons (the green line), multiple π 0 mesons (the blueline), and ω mesons (the purple line), as shown in Fig. 2. The latter two processes become backgrounds
when one or a few γ-rays escape from the forward acceptance hole of the BGOegg calorimeter (θ < 24◦ ).
Justiﬁcation of these functions were carefully examined by using the real data and the MC simulation.
While background-function ﬁts to the higher-momentum sample (Pη′ > 1 GeV/c) and the liquidhydrogen-target sample show reasonable χ2 values, the same ﬁtting method for the lower-momentum
sample (Pη′ < 1 GeV/c) returns a larger χ2 value. Therefore, we ﬁtted the background functions notby using the data points in a mass range, where an increase of events was seen. In the case of Fig. 2, a
range of 870 < Mγγ < 930 MeV/c2 was omitted from the ﬁt, and a statistical signiﬁcance of the excess
over a sum of the ﬁtted background functions was estimated to be 3.6σ in the omitted mass range.
Such a signiﬁcance is also being obtained by a χ2 difference test, which compares two ﬁts: one using
only background functions and the other using the same background functions and a signal function,
simulated by taking into account a density distribution inside a nucleus. Although it is hard to conclude
the existence of η ′ -mass reduction due to the insufﬁcient statistics, an amount of the reduction can be
anyway evaluated from a ﬁt with the signal function which provides the maximum signiﬁcance. A mass
value of the possible excess does not contradict the ﬁrst result from the η ′ bound nuclei search, which- 62 -

ELPH Annual Report, Tohoku University (2019)indicates the optical potential does not exceed about 100 MeV. Now various systematic uncertainties forthe spectral line shape of the reconstructed η ′ mass are also being examined.

§ 4. Prospect
We are going to conﬁrm the two analysis results by an additional data, which has been collectedwith a carbon target and whose statistics is similar to the analyzed data. In addition, we plan the nextphase BGOegg experiment with the setup dedicated to the direct measurement of the γγ spectrum witha target made of copper, whose nuclear radius is 1.8 times larger than that of carbon, and a forward γ
detector, composed of 252 PWO crystals and covering the acceptance hole of the BGOegg calorimeter.
Backgrounds from multiple meson photoproduction will be more than one order of magnitude reducedby almost the 4π coverage of electromagnetic calorimeters. A sensitivity of signal detection is expected
to increase signiﬁcantly.

References[1]

N. Muramatsu et al.: Phys. Rev. C 100 (2019) 055202.

[2]

N. Muramatsu et al.: Phys. Rev. C 102 (2020) 025201.

[3]

H. Nagahiro, M. Takizawa, and S. Hirenzaki: Phys. Rev. C 74 (2006) 045203.

[4]

S. Sakai and D. Jido: Phys. Rev. C 88 (2013) 064906.

[5]

S.D. Bass and A.W. Thomas: Phys. Lett. B 634 (2006) 368.

[6]

N. Tomida, N. Muramatsu, M. Niiyama et al.: Phys. Rev. Lett. 124 (2020) 202501.

[7]

N. Tomida: 5th CLUSTER Workshop, 25 Sep 2020.

[8]

H. Nagahiro: J. Phys. Soc. Jpn. Conf. Proc. 13 (2017) 010010.

[9]Y. Matsumura, H. Shimizu, N. Muramatsu et al.: 75th JPS meeting (2020) 17aK15-2.

[10] Y. Matsumura: Doctoral Thesis (in preparation), Tohoku Univ.

- 63 -

ELPH Annual Report, Tohoku University (2019)- 64 -

ELPH Annual Report, Tohoku University (2019)

3D magnetic field mesurement of
SCRIT electron spectrometer
H. Wauke1 , H. Honda1 , T. Suda1 , D. Taki1 , and K. Tsukada1,2
1Research Center for Electron Photon Science, Tohoku University, Sendai, 982-0826
2

Institute for Chemical Research, Kyoto University, Uji, 611-0011

The 3D magnetic field measurement of the SCRIT electron spectrometer was performed with accuracy of ∆B/B ∼ 10−3 in November 2019, aiming at improving the momentum resolution of the spectrometer. The measured magnetic field distributions are similar to these of the calculated ones and theirdifferences were found to be ∼10−3 T. The electron scattering experiments using carbon targets were
performed to compare the momentum resolutions derived using the calculated maps and the measured
ones.

§ 1. Introduction
The SCRIT ( Self–Confining Radioactive–isotope Ion Target ) [1, 2] electron scattering facility has
been built at RIKEN RI beam factory for electron scattering off unstable nuclei. WiSES ( Window–
frame Spectrometer for Electron Scattering ) is an electron spectrometer for the SCRIT experiment.
WiSES consists of a dipole magnet, two drift chambers placed at the entrance and exit of the magnet, a helium bag installed between the two drift chambers to reduce the multiple scattering effect,
and two scintillation counters for trigger generation. The solid angle of the spectrometer is about 80
msr, covering a wide range of scattering angles, i.e. from 30◦ to 60◦ . The WiSES gap has a size of1700 (width) × 290 (height) × 1400 (depth) mm3 to obtain high statistics for low luminosity. A momentum resolution of ∆p/p ∼ 10−3 is required to separate elastic and inelastic scattering with WiSES foran electron energy in the range of 150–300 MeV. The momentum resolution evaluated in past elastic
scattering experiments was found not to reach the design value. One possible season is that the map
calculated using OPERA3D to reconstruct the trajectories of the scattered electrons does not reproduced
the WiSES magnetic field with enough accuracy. In this paper, the results of the 3D magnetic fieldmeasurement of the magnet and the performance study of the WiSES are reported.

§ 2. 3D magnetic field measurement
The 3D magnetic field measurement of WiSES with the measured accuracy ∆B/B ∼ 10−3 wascarried out. The magnetic field strength was 0.4–0.8 T, which corresponds to the experiments with theelectron beam energy of 150–300 MeV. Figure 1 shows the 3D magnetic field measurement system. A
probe head made from three Hall probes and a 3D driving device consisting of three electric sliders thatmove in a large measurement area (500 (width) × 300 (height) × 850(depth) mm3 ) were developed. The- 65 -

ELPH Annual Report, Tohoku University (2019)probe head can be measure three magnetic field components simultaneously. The measurement resolution of these probes is about 10−6 T. The 3D driving device was controlled by the LabVIEW program
to be measured in steps of at ∼10 mm intervals. The program also reads the field values from the Hall
probes and the absolute magnetic field of the WiSES magnet is continuously normalized by using nuclear
magnetic resonance (NMR).

(a)

Bz [ T ]By [ T ]Fig.1. The 3D magnetic field measurement of WiSES system.

0.8
0.6
0.4
0.2

measured map
calculated map
difference × 50(b)0measured map

field
clamp

0.2

calculated map
difference × 50

00.2 magnet pole
0 200 400 600 8001000
Z [mm]

0.4

field
clamp

magnet pole

0 200 400 600 8001000
Z [mm]

Fig.2. Comparison between the measured map and the calculated one near the magnetic pole.
The strength of the magnetic field was 0.8 T. (a) shows vertical component By and (b)shows horizontal component of the fringing field Bz . The red line is the measured map,
blue line is the calculated one, and green line shows 50 times the difference between thetwo maps.
Figure 2 shows the vertical component By and the horizontal component of the fringing field Bz of
the measured map and the calculated one. The structure of the measured magnetic field agrees will tothe calculated one even at about 1 cm from the magnet pole. Over the entire measurement area, theirdifferences are order of ∼10−3 T. Similar results were obtained for other magnetic field strengths.

- 66 -

ELPH Annual Report, Tohoku University (2019)§ 3. Performance study
In November 2019, it was investigated by electron scattering with carbon targets whether the differences of the calculated maps and the measured ones affects the momentum resolution. The momentum
resolution is obtained from the width of the elastic scattering peak observed in the experiments. The
resolution was obtained using the measured maps and the calculated maps.
Figure 3 shows the result, ϕ is the azimuth angle of the scattered electrons as viewed from thetarget. At three electron energies, namely 150, 200 and 300 MeV, the momentum resolutions obtained

δp/p[×10-3]

from the measured map in this study agree well with those that obtained from the calculated one.

5
4

150 MeV

200 MeV

150 MeV(sim)
150 MeV(this work)

200 MeV(sim)
200 MeV(this work)

300 MeV
300 MeV(sim)
300 MeV(this work)

3
2
0

-5

5 φ [deg]

Fig.3. Comparison of the momentum resolution between the measured map and the calculated
one. The solid lines show the simulation results, the open circles show the results obtained with the calculation map, and the filled circles show the results obtained with themeasured map. Red indicates the results with 150 MeV, green indicates the results with
200 MeV, and blue indicates the results with 300 MeV.

§ 4. Conclusion and future
WiSES is an electronic spectrometer for SCRIT experiments. In order to improve the momentum
resolution of WiSES, the 3D magnetic field distributions with the magnetic field strengths corresponding
to the energy (150–300 MeV) used in the experiment was measured. As a result, the structure of themagnetic field distributions measured at the magnetic field strength of 0.4–0.8 T were similar to thecalculated ones, with the differences of 10 −3 T over the entire measurement area. An electron scatteringexperiment using carbon targets was conducted to confirm the effect of the momentum resolution due tothe above differences, but there were almost no differences from the ones obtained from the simulation.
Further study to account for the difference of the WiSES momentum resolution between the simulated and experimental values is still ongoing.

References[1]

M. Wakasugi et al., Phys. Rev. Lett. 100, 164801 (2008).

[2]

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

[3]

K. Tsukada et al., ELPH Annual Report 2018 Vol. 7, Tohoku University, 81 (2018).

- 67 -

ELPH Annual Report, Tohoku University (2019)- 68 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2879)

The position and proﬁle measurement of the positron beamline at ELPH
M. Miyabe1 , M. Okabe1 , Y. Sada1 , H. Saito1 , J. Takahashi1 , M. Tsuruta1 ,C. Yoshida1 , and GeV-γ group1
1

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

In the GeV-γ experimental hall of Research Center for the Electron PHoton Science (ELPH), The
positrons and electrons, which are produced at a metal plate in front of the bending magnet RTAGX bybremsstrahlung photon beam generated from the electron storage ring, are provided at three beamlines.
The positron beamline is guided in the 30 degree direction from the RTAGX dipole magnet. It is used
for detector performance evaluation experiments with 50 MeV to 800 MeV positron. Positron beamline is suspected that the beam is slightly downward with respect to the reference height of the GeVγ Experimental hall, and past experimental results show a similar tendency. We don’t understand
why the beam direction is not horizontal, but the direction of the gamma beam or the alignment of the
RTAGX magnet are considered as a possibility. In this experiment, the beam proﬁle is measured at two
points on the positron beamline and the orbit of the positron beam was measured.

§ 1. Introduction
The positrons and electrons, which are produced at a gold or tungsten or brass plate as a converterin front of the bending magnet RTAGX by the photon beam, are provided at three beamlines in the GeVγ experimental hall. The generated positrons are momentum-analyzed by the RTAGX dipole magnet
and guided in the 30 degree direction with respect to the photon beamline. The momentum of positrons
is selected by the current of RTAGX and transported to the beamline. The positron beam is used for
detector performance evaluation experiments. In addition, the triplet quadrupole magnets RFQ for
positron beamline is installed to focus the beam. Especially, it is effective when using a low-energy
positron beam.
From the results of some experiments, the positron beam direction is slightly downward with respect to the reference height of the GeV-γ experimental hall. The purpose of this experiment is toaccurately measure the beam trajectory. We don’t understand the reason why the beam direction is
not horizontal, but the direction of the gamma beam, the alignment of the RTAGX magnet, etc. areconsidered as a cause. In this experiment, a new position detector using scintirating ﬁbers and MPPCs
was manufactured. By measuring the beam shape at two points on the beamline at the same time, theshape and direction of the positron beam at each point can be measured. We investigate a cause fromresults of these measurement. In addition, the new position detector is used as an online beam monitor
for shared-use at a positron beamline.

- 69 -

ELPH Annual Report, Tohoku University (2019)§ 2. Experimental setup and results
The experiment was carried out in June 2019 at the positron beamline in the GeV-γ experiment hall
at Research Center for Electron PHoton Science (ELPH). Initially we planned to install two beam proﬁlemonitors (BPM) for beam shape measurement at two locations on the beamline and measure the beam
trajectory at the same time. Unfortunately, when the newly created νBPM consisting of 50 channelsof 1 mm square ﬁber is installed in the positron beamline, Since the NIM-EASIROC used for readout
signals did not work due to the noise, simultaneous measurement at two points was abandoned. In thisreport, only one BPM (eBPM ) was installed at two different places on the positron beamline. The beam
orbits were obtained by the twice measurement by different setup. The experimental setup is shown in
Figures 1 and 2.
The eBPM is consisted of 32 channels of 3 mm square scintirating ﬁbers and two layers. eBPM detects

Fig.1. Schematic drawings of the experimental
setup.

Fig.2. Experimental setup photograph fromdownstream.

the position of each x and y positron beam. 5 mm thick plastic scintillators were installed at upstream
and downstream of eBPM (TRIG1,TRIG2). (TRIG1, TRIG2) generated the trigger signal with eBPM .
Positron beam momentum was selected while changing the current value of RTAGX from 100 A to 400 A
The beam position and shape were measured at two points, 250 mm and 2600 mm, from the beam pipe of
the positron beamline. Figure 3 shows The beam shape when the current value of RTAGX is 300 A. The
obtained beam shape is projected on each of the x and y axes and ﬁtted with a Gaussian distribution. The
center value (µx,y ) and width (σx,y ) of the beam were shown in Fig. 4. Tables 1 and 2 show a list of thecenter values and widths of the beams obtained for each RTAGX current value. Figure 5 shows the orbitof the positron beam. Obtained results show that the beam center shifts in the + x and + y directions as
the current value increases. It was also found that the width of the beam was the maximum value (σx ,- 70 -

ELPH Annual Report, Tohoku University (2019)σy ) = (25.3, 18.9) mm at 2600 mm downstream.
Table 1. center value and width of the positron
beam at 250 mm downstream frombeam pipe
RTAGX current [A] µx
σx
µy
σy
100
2.2 18.3 0.0 10.1
230
2.5 16.4 0.7 9.5300
3.2 16.0 1.1 9.2
400
4.5 15.9 1.6 9.1

Table 2. center value and width of the positron
beam at 2600 mm downstream frombeam pipe
RTAGX current [A] µx
σx
µy
σy
100
3.5 25.3 -0.97 18.9
230
4.4 24.5 0.67 14.4
300
5.2 23.0 0.91 13.5400
8.2 22.9
2.3
12.6§ 3. Summary
This time, the beam proﬁle measurement of the positron beamline at Research Center for Electron
PHoton Science, Tohoku University. At ﬁrst, it was planned to measure the beam shape at two points on
the beam line at the same time, but the prepared detector did not work correctly, therefore, the similar
detector eBPM was used to measure two points independently. As a result, it was found that the positron
beam size spreads up to about 25 mm at the downstream. Also, we found that the center of the orbit
deviates depending on RTAGX current value. In the Next experiment, we improve the νBPM readout
system and perform the simultaneous measurement at two locations on the positron beamline. And we
also measure the effect of the RFQ magnet. (Adopted ELPH#2932).

- 71 -

ELPH Annual Report, Tohoku University (2019)

Fig.3. positron beam shape at 250mm downstream
from beam pipe with RTAGX current is 300 A

Fig.4. X (upper) and Y (lower) direction
projected beam shape- 72 -

δx(mm)

ELPH Annual Report, Tohoku University (2019)

10
9
8
7
6
5
4
3
2
1
0

400A
300A
230A
100A

0

500

1000

1500

2000

2500

3000

3500

δy(mm)

z(mm)
8
7
6
5
4
3
2
1
0
-1
-2

400A
300A
230A
100A

0

500

1000

1500

2000

2500

3000

3500

z(mm)

Fig.5. Obtained trajectory of the positron beam. center value and width in x direction (upper),y direction (lower). Error bar shows the 10 times value of the width.

- 73 -

ELPH Annual Report, Tohoku University (2019)- 74 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2919, #2936)

Development of a spectrometer for ULQ2 experiment
Y. Honda1 , T. Aoyagi1 , C. Legris1 , T. Goke1 , K. Ishizaki1 , H. Kikunaga1 ,Y. Maeda2 , S. Miura1 , M. Miyabe1 , T. Muto1 , K. Namba1 , K. Nanbu1 ,S. Sasaki3 , T. Suda1 , K. Takahashi1 , S. Takayama1 , D. Taki1 , T. Tamae1 ,A. O. Tokiyasu1 , K. Tsukada4 , N. Tsukamoto3 , H. Wauke1 , and Z. Hang2
1

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

Faculty of Engineering, University of Miyazaki, Miyazaki, 889-2192, Japan
3
4

Department of Physics, Tohoku University, Sendai, 980-8578, Japan, Institute for Chemical Research, Kyoto University, Uji, 611-0011, Japan

Proton charge radius has a serious inconsistency since 2010. ULQ2 (Ultra Low Q2 ) experiment
aims to determine the proton radius with low-energy electron scattering as small model dependence aspossible. We have developed a new spectrometer for the ULQ2 experiment. The spectrometer is designed
to measure momentum and scattering angle of electrons from a position on the focal plane detector due
to a difficulty of a tracking of a low-energy electron. The designed spectrometer satisfies experimental
requests such as momentum resolution, angular resolution, and acceptance. The spectrometer has been
constructed in the first experimental hall of ELPH in March 2019 . A commissioning of the spectrometerand beam line are planed in 2020.

§ 1. Introduction
Proton charge radius has a serious inconsistency since 2010. Until 2020, the proton charge radius
was thought to be 0.8775(51) fm [1], based on the measurements with electron scattering and hydrogen spectroscopy. However, the radius measured with muonic hydrogen spectroscopy was reported as
0.84184(67) fm [2] which is 7σ smaller from the previously accepted result. That is called proton radius
puzzle. Until now, the radius has been newly measured with hydrogen spectroscopy and electron scattering, but the result is divided into around 0.84 and 0.88 fm. [3–6] The puzzle is getting more confused.
ULQ2 (Ultra Low Q2 ) experiment is aiming at determining the proton radius with the electron
scattering with removing model dependence as much as possible. The features of the ULQ2 experimentare as follows : absolute cross section measurement with high accuracy of 10−3 , measurement at low
momentum transfer region of 0.0003 ≥ Q2 ≥ 0.008 (GeV/c)2 , and experimental separation of charge
and magnetic form factor (Rosenbluth separation). In this report, we report on a development of aspectrometer for the ULQ2 experiment.

- 75 -

ELPH Annual Report, Tohoku University (2019)§ 2. Spectrometer development
We have developed a new spectrometer for ULQ2 experiment. The spectrometer is designed tomeasure momentum and scattering angle of electrons from a position on the focal plane detector due
to a difficulty of a tracking of a low-energy electron. Due to the limitation of the space and budget,the spectrometer has a simple configuration consisting of a dipole magnet and focal plane detectors.
A two dimensional position sensitive detector is installed on the focal plane of the dipole magnet, andthe momentum and scattering angle are determined from the detected position instead of the tracking.
From the experimental request, we aimed for momentum resolution of σp /p ≤ 10−3 , scattering angle
resolution of σθ ≤ 5 mrad, and acceptance solid angle of Ω ≥ 10 mSr.
We used Orbit4 [7] to design the spectrometer. We calculated magnet shape which maximizes resolutions and acceptance under conditions that the distance between target and entrance of the magnet
L1 is 500 mm, curvature of radius ρ is 500 mm, bending angle θb is 90◦ , and gap of the pole piece d is 70
mm. The calculated transfer matrices are summarized in table 1.
Table 1. Summary of the transfer matrix of the spectrometer

x
ϕ
x
ϕ
x
ϕ
x
ϕ
y
θ

x
-0.31127-5.27612δδ-0.35319-0.62332xϕδ
10.19699
6.24398
ϕyy
2.91029150.26016
y-1.99660-3.15227ϕ
0.00001-3.22143yy-0.34478-0.40122xδδ
-1.95559-5.01064ϕyθ
20.65081
118.15029
θ
0.853390.84649δ
0.597640.19172yθ-0.47833-3.50290xyy-24.38432
550.34503
ϕθθ
2.4975414.07843
yx
48.29457
62.24168xx-0.16839
11.37759θθ-0.32271
1.34522xyθ
7.68791557.04736
δδδ0.330390.15148yϕ8.53570
10.44631

xϕ0.144433.34719xxx-35.67131-91.54606
xθθ-2.26485
117.57027
δyy-0.70422
45.53897
yδ
4.723315.31752xδ
2.851700.46984xxϕ-63.05219-80.28996
ϕϕϕ-6.58477-3.89761
δyθ-5.04930
39.45752
θx14.9080217.40900

ϕϕ-0.00147-1.65686xxδ4.25015
6.33960
ϕϕδ4.35684
0.99549δθθ-1.16769
18.25986
θϕ-0.00066-0.84716ϕδ
1.68857-0.61295xϕϕ-35.82395-25.54731
ϕδδ
-0.88163-3.37141θδ
2.96383
4.40906

After the Orbit4 calculation, we check the consistency of the transfer matrix from Orbit4 and fromelectron’s trajectory calculation with magnetic field calculated by TOSCA [8]. As a result of that, wefound small inconsistency of (y|θ) which is mainly controlled by the angle of the entrance and exit of
the magnet, β. Therefore, we make smaller the angle of the entrance by 8◦ so that the (y|ϕ) from the
trajectory calculation is the same as one from Orbit4. The difference seems to be due to the fact thatthe shape of the fringing magnetic field is not completely introduced. Finally, we got the spectrometer’s
configuration as shown in table 2.
The shape of the entrance and exit of the magnet is designed to maximize the resolutions andacceptance. Figure 2 shows the lay-out of the spectrometer. The shape of the entrance and exit of the- 76 -

ELPH Annual Report, Tohoku University (2019)

Table 2. Summary of the configuration of the spectrometer
Target to Entrance
MagnetEntrance shape
Exit shape
Exit to Detector

L1
500 mm
ρ
500 mma1-856.77a1
404.23L2
440 mm

θb
90◦
a2
0
a2
79514

d
70 mm
β
51.267◦β37.495◦l36.2 mml-34.4 mmFig.1. Lay-out of the spectrometer.

magnet is written as,

 






x′
cos(θb + β) − sin(θb + β)xcos θb − 1− sin(α + β)=
 + ρ
+l

(1)
y′
sin(θb + β) cos(θb + β)ysin θbcos(α + β)
Here,
y=

α=

a1 2
a2
x + 2 x3 ,ρρ0 (entrance)

θb

(2)

(3)

(exit).

The entrance and exit of the magnet have large angle with respect to the center trajectory to control(y|θ) by focusing and defocusing the electrons with fringing field. It improves the Ω and σθ about twice.

- 77 -

ELPH Annual Report, Tohoku University (2019)

The second and third function shape of the pole piece controls a part of the transfer matrices such as(x|ϕϕ), (y|θϕ), (x|ϕϕϕ) and (x|ϕϕδ) to archive smaller σp and σθ . Performance of the spectrometer
was estimated with simulation, and summarized in table 3.
Table 3. Design parameter of the spectrometer
Maximum center momentum (MeV/c)
Maximum induction (T)Momentum acceptance (%)
Horizontal angular acceptance (mrad)
Vertical angular acceptance (mrad)
Solid angle (mSr)
Scattering angle range (◦ )Angle of focal plane (◦ )Dispersion to magnification (mm/%)Momentum resolution
Angular resolution (mrad)

75
0.5
11
± 50
± 50
10
30 − 150
44.2
8.34
8 × 10−4
5§ 3. Conclusion and future
In simulation, the spectrometer satisfies the experimental requests as summarized in table 3. The
spectrometer has been constructed in the first experimental hall of ELPH in March 2019 . A commissioning of the spectrometer and beam line are planed in 2020.

Fig.2. Picture of the spectrometer and ULQ2 beam line.

Acknowledgments
This work was supported in part by JSPS KAKENHI Grants Nos. 16H06340, and 18K13553.

- 78 -

ELPH Annual Report, Tohoku University (2019)

References[1]

P. J. Mohr, B. N. Taylor, and D. B. Newell, Rev. Mod. Phys., vol. 84, no. 4, pp. 1527–1605, Nov. 2012.

[2]

R. Pohl et al., Nature, vol. 466, no. 7303, pp. 213–216, 2010.

[3]

A. Grinin et al., Science (80-. )., vol. 370, no. November 3, pp. 1061–1066, 2020.

[4]

W. Xiong et al., Nature, vol. 575, no. June, pp. 147–151, 2019.

[5]

H. Fleurbaey et al., Phys. Rev. Lett., vol. 183001, pp. 1–5, 2018.

[6]

N. Kolachevsky et al., AIP Conf. Proc., vol. 1936, 2018.

[7]

S. Morinobu, User manual of program ”Orbit4”, Private communication.

[8]

OPERA 3D (TOSCA) https://www.3ds.com/products-services/simulia/products/opera/.

- 79 -

ELPH Annual Report, Tohoku University (2019)- 80 -

ELPH Annual Report, Tohoku University (2019)(ELPH Experiment : #2844, #2882, #2894, #2924, #2934)

Development of a silica aerogel Cherenkov detector for
π/K separation fitted to the FOREST/BLC experiment
T. Yuzawa1 , Y. Emoto1 , K. Fujihara1 , T. Ishikawa2 , R. Kanai1 , H. Kawai1 ,S. Kimata1 , S. Kimura1 , A. Kobayashi1 , M. Miyabe2 , K. Okuhata1 ,and M. Tabata1 for the FOREST/BLC collaboration
1
2

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

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

We are developing a silica aerogel Cherenkov (AC) detector for π/K separation fitted to the FOREST/BLC experiment. We have used 8 silica aerogel blocks to construct an AC radiator with a size of
200×200×30 mm3 . The refractive indices (n) of aerogel used are 1.12 and 1.09. The PMTs, Hamamatsu
H3178-60, are connected to the AC radiator through an air gap. We have investigated the performance ofthe developed prototype and actual AC detectors three times using 600-MeV/c positrons at ELPH. Using a mirror-type reflector is found to be advantageous over a diffuser-type one for guiding a Cherenkov
light to the PMTs. The distance of the air gap between the AC radiator and the PMT windows shouldbe less than 30 mm to get enough light yield. The developed AC detector with n = 1.12 satisfies highseparation power between π and K in the FOREST/BLC experiment for studying Λn interaction.

§ 1. Λn interaction
Charge symmetry (CS) is an important concept for describing many facets of nuclear physics: observables are hardly changed when all protons and neutrons are replaced with neutrons and protons,
respectively. CS corresponds to invariance under the interchange of u and d quarks, and CS breaking (CSB) takes place owing to differences of u and d masses and electromagnetic effects. Recently, an
unexpectedly large difference in the excitation energies is observed between the 4Λ He and 4Λ H mirror
hypernuclei [1, 2]. CSB possibly occurs more strongly in hypernuclei than in ordinary nuclei. The fullunderstanding of CSB still remains an open issue in nuclear physics. To reveal the cause of CSB, it isimportant to investigate the low-energy Λn and Λp scatterings.
How can we get the low-energy scattering parameters? The best way is to perform scattering experiments at low energies. Unfortunately, ΛN scattering experiments are difficult to be realized owing
to the unstable nature of the Λ hyperon. In such a case, the final-state interaction (FSI) is often utilized
alternatively. When more than two particles are generated in the final state, the relative momentum(or the invariant mass) distribution of the two particles are distorted near the threshold. The lowenergy Λp scattering parameters have been determined by fitting the Λp invariant mass spectrum inthe pp → K + Λp reaction and total cross section of the free Λp scattering simultaneously [3]. The scat-- 81 -

ELPH Annual Report, Tohoku University (2019)+0.16
tering length and effective range are −2.43+0.16−0.25 fm and +2.21−0.36 fm for the spin-singlet state, and+0.6
those are −1.56+0.19−0.22 and +3.7−0.6 fm for the spin-triplet state. Currently, we do not have information on

Λn scattering separately from Λp scattering although some constraints are provided from the detailed
studies of the structures of hypernuclei.
A possible way to extract the Λn scattering parameters is K + photoproduction on the deuteron [4–7]. The quasi-free K + photoproduction on the bound proton γp → K + Λ is the corresponding elementary
process, and the produced Λ is likely to interact with the spectator neutron at a specific kinematics.
When we detect K + s at extremely forward angles, distortion by the Λn FSI enhances the event yieldat the highest K + momentum region (near the Λn threshold region in the Λn invariant mass distribution) [8–20].
The FOREST/BLC experiment [21] primarily aims at determination of the low-energy ηN scattering parameters by using the γd → ηpn reaction at a specific kinematics for investigating the internal
structure of the nucleon resonance N (1535)1/2− , which is speculated to be the chiral partner of thenucleon [22, 23]. The kinematics is similar to the γd → K + Λn reaction for investigating the Λn interaction. In γd → ηpn, the forward going protons are momentum-analyzed with particle identification
using the BLC spectrometer, and η mesons are identified by two photons detected with the FOREST
detector [24].
What we have to do is momentum analysis of the forward going K + s with particle identification in
γd → K + Λn since K + must be associated with hyperon (Λ, Σ0 , or Σ− ) production. The Λn invariant
mass can be calculated as the d(γ, K + ) missing mass in γd → K + Λn. Basically, γd → K + Λn can beseparated from γd → K + Σ0 n and γd → K + Σ− p by detecting daughter particles π − p or π 0 n from the Λ
decay without any additional photon from the Σ0 decay. Even if the daughter particles form the Λ decay
are not detected, mis-identification of hyperons does not affect the low-mass region in the d(γ, K + )missing mass, where the Λn FSI enhances the event yield, in γd → K + Σ0 n and γd → K + Σ− p. In
this regard, to measure the singles K + momentum distribution at a fixed incident photon energy is ofprimary importance for investigating the Λn interaction.
Positrons, pions, kaons, and protons are detected with the BLC spectrometer. Most of the detectedparticles are positrons converted by pair production from the incident untagged and tagged photons.
Additionally, much more positive pions are expected to be produced than kaons. It is important toincrease the quality of K + identification for measuring the singles momentum distribution where we
do not require daughter-particle detection from hyperons. Therefore, we have developed a silica aerogel
Cherenkov counter for π/K separation fitted to the FOREST/BLC experiment.

§ 2. Silica Aerogel Cherenkov dectector
In the FOREST/BLC experiment, the forward spectrometer is placed behind the large-solid angle
FOREST electromagnetic calorimeter. The forward spectrometer consists of a dipole magnet called BLC,
2 planar drift chambers (DCs) for the trajectory measurement, 14 plastic scintillators (PSs) for the timeof-flight measurement, and SF5 lead-glass Cherenkov counter for e/π separation. Fig. 1 shows the- 82 -

ELPH Annual Report, Tohoku University (2019)

PSs
SF5 for e/π
DCs

FORESTγ γ

photon beamΝ

forward spectrometerFig.1. Experimental setup for the FOREST/BLC experiment. The momentum and time of flightof a charged particle emitted at 0◦ are measured through a bending magnet called BLC
behind the FOREST detector. The trajectory is measured with two planar drift chambers(DCs), and the time of flight is measured with hodoscope comprised of 14 plastic scintillators (PSs). Additional e+ /π + separation is made using SF5 lead-glass Cherenkov
counters.

Fig.2. Cross sectional view of the detector placement for the BLC spectrometer. The distanceis approximately 125 mm between the rear face of the downstream DC and front face ofPSs.

- 83 -

ELPH Annual Report, Tohoku University (2019)

experimental setup for the FOREST/BLC experiment. Not to disturb the trajectory measurement of acharged particle, we plan to place a detector system for π/K separation in the space between the rearface of the downstream DC and front face of PSs.
Since the maximum momentum of K + emitted at 0◦ in γd → K + Λn is approximately 1.0 GeV/c, we
consider a detector made up of silica aerogel with a refractive index of 1.12, in which a Cherenkov light is
not emitted by 1.0-GeV/c kaons but it is emitted by pions with the same momentum. In this regard, we
have started to develop a silica aerogel Cherenkov (AC) detector for π/K separation. We have decided
the effective area of the detector is a square with a side of 200 mm, and to use 1.5-inch photomultipliertubes (PMTs), Hamamatsu H3168-60. To avoid the placement of thick material within the effective areaof the BLC spectrometer for the momentum analysis of charges particles, the photocathode window of a
PMT should be placed with a distance of 230 ∼ 250 mm from the horizontal plane including the central
course of the photon beam. Fig. 2 shows the cross sectional view of the detector placement for the BLC
spectrometer. The distance is approximately 125 mm between the rear face of the downstream DC andfront face of PSs. It should be noted that the entrance and exit windows made of Mylar film in DC blisterowing to the pressure difference inside and outside DC. We have required that the detector thickness
is less than 90 mm. To get enough light yield, we have used two layers of 15-mm thick aerogel blocks,
namely 30 mm thick in total.

§ 3. Beam tests
We have tested prototype and actual AC detectors three times using 600-MeV/c positron beams [25]at the Research Center for Electron Photon Science (ELPH), Tohoku University [26]. Here, we briefly
describe the results from these beam tests.
3.1 Diffuser or mirror
The first beam test aimed at comparison of reflector types, diffuser or mirror, for guiding a Cherenkov
light to the PMT windows. Fig. 3 shows the schematic view of the prototype AC detectors tested in thefirst beam test. We have adopted three layers of PTFE-film sheets as a diffuser-type reflector, and each
sheet measures 80 µm in thickness. We have adopted a layer of aluminized PET-film sheet with a thickness of 12 µm as a mirror-type reflector. To collect Cherenkov photons effectively from 500-MeV/c π + s,
additional two planar mirrors are placed at the center with a tilting angle of 55◦ with respect to thecentral plane. The distance of an air gap was fixed at 50 mm between the edge of the radiator and PMT
windows for both the prototype detectors. The silica aerogel radiator measured a square of 200 × 200
mm2 , and a thickness of 30 mm. Since a size of a single block of the silica aerogel was approximately
100 × 100 × 15 mm3 , we piled up eight blocks to construct the silica aerogel radiator. Fig. 4 shows theplacement of silica aerogel blocks and photo of them.
The performances of the prototype AC detectors were investigated using a 600-MeV/c positron
beam at ELPH. The impact position of a positron was determined with two plastic scintillators placed at∼ 300-mm upstream and downstream of a prototype detector on the beamline. Each plastic scintillator- 84 -

ELPH Annual Report, Tohoku University (2019)

PMT
50 mm

PMT

90 mm

55 deg
200 mmwrapped withPTFE film

wrapped with
Aluminized PET film

30 mm

PMT

PMT

Fig.3. Schematic view of the prototype AC detectors tested in the first beam test.

Fig.4. Placement of silica aerogel blocks to construct the Cherenkov radiator with a size of 200×
200 × 30 mm3 (left), and photo of them (right).

7 PMTs

7 PMTsFig.5. Impact positions of positron beams (left) and light yield as a function of the X position(corresponding to the distance from the PMT windows) for the mirror-type prototype detector (right).

- 85 -

ELPH Annual Report, Tohoku University (2019)
measures a size of 5 × 5 × 5 mm3 . During the beam test, the prototype detectors are rotated by 90◦ withrespect to the beam axis. The X, Y , and Z axes are defined to give the position corresponding to the
distance from the PMT windows, that orthogonal to it in the effective area of the silica aerogel radiator,and depth, respectively. Fig. 5 shows the impact positions of positrons and light yield as a function of
the X position for the mirror-type prototype detector. The light yields highly depend on the X position,and similar light yields are obtained for different Y positions for the same X.
A finite light yields were obtained even if the radiator was not placed. The light yields were 11.7
and 0.7 photoelectrons (pe) with and without the radiator, respectively, at the center for the mirror-type
detector. Those were 13.0 and 2.8 pe at the ceter for the diffuser-type. The intrinsic light yield from theradiator was slightly larger for the mirror-type. Table 1 summarizes the mis-identification probability
and efficiency for several threshold values for the mirror- and diffuser-type prototype detectors. Here,the mis-identification probability is defined as a probability for responding even if the radiator is notplaced, giving the probability that a kaon is erroneously recognized as a pion. To get high efficiency
and low mis-identification probability simultaneously, the mirror-type detector was found to be muchadvantageous.
Table 1. Mis-identification probability and efficiency for several threshold values. The misidentification shows a probability for responding even if the radiator is not placed, and#pe stands for the number of photoelectrons.
mirror typethreshold (#pe)
1.5
2.0
5.0
5.5

mis-identification
7.5%
4.3%
0.4%
0.3%

efficiency
98.8%
98.2%
87.9%
85.3%

diffuser typemis-identification
48.3%
37.4%
5.9%
4.4%

efficiency
99.9%
99.8%
96.6%
95.4%

3.2 2nd beam test
The second beam test aimed at increasing the light yield in the mirror-type detector. We have
reduced the air-gap distance from 50 to 30 mm. Owing to the space for the PMT placement as shown in
Fig. 2, only 4 PMTs can be placed in the lower side. Thus, the position and tilting angle of the central
tilted mirror were modified, or an additional mirror was introduced. Fig. 6 shows the schematic view ofthe prototype AC detectors tested in the second beam test. Although the available space for the PMT
placement in the bottom is downstream side, the beam test was performed with placing PMTs in the
opposite upstream side as shown in Fig. 6. Thus, the results did not make sense from the modificationsof the position and tilting angle of the central tilted mirror and introduction of an additional mirror.
However, the light yield obtained from the PMTs in a side was found to be a (linear) function of the
distance from the PMT windows by combining the results from the first and second beam tests. It is
important to minimize the air-gap distance for maximizing the light yield. The threshold value of 5 pe
was expected to give an efficiency higher than 99% for the air-gap distance 20 ∼ 30 mm even if we did- 86 -

ELPH Annual Report, Tohoku University (2019)

PMT

55 degwrapped withaluminized PET film
PMT
Fig.6. Schematic view of the prototype AC detector tested in the second beam test. The position
and tilting angle of the central tilted mirror are modified (red), or an additional mirror isintroduced (blue).

20

center50 mm shifted

18
16
14
Npe

12
10
8
6
4
2
0

0

25

50
75 100 125 150
Distance from PMT (mm)

175

200

Fig.7. Light yield as a function of the PMT windows. The light yields are almost the same fordifferent Y positions. The blue and cyan markers are obtained in the first beam test, andthe red and magenta in the second. Each of the vertical lines corresponds to the data
positron beam is injected at the center between the top and bottom PMT windows. The
blue and red markers represent the light yields obtained from 7 PMTs, and cyan andmagenta represent those from 4 PMTs.

- 87 -

ELPH Annual Report, Tohoku University (2019)not modify the position and tilting angle of the central tilted mirror or introduce an additional mirror.
3.3 3rd beam test
Since an efficiency is expected to be higher than 99% with an air-gap distance of 20 ∼ 30 mm andthreshold value of 5 pe, we have constructed the AC detector to be used in the FOREST/BLC experiment.
We investigate the performance of this actual detector in the third beam test. Fig. 8(left) shows a photoof the AC detector. To reduce the material through which charged particles pass, each of the tilted
mirrors plays a role as a wall. The 7 PMTs are connected in the upper side, and 4 PMTs are connectedin the lower downstream side. The air-gap distance was fixed at 30 mm. The silica aerogel radiator
was mounted on a dummy block, and supported by threads. The dummy block was a silica aerogel witha size of 40 × 25 mm3 and a refractive index of 1.03. Fig. 8(upper right) shows a photo of the dummy
block and supporting threads for the radiator placement. All the silica aerogel blocks to be used in theradiator were replaced with new ones without any cracks. Since the transparency is much higher for a
low refractive index aerogel than a higher one, we used four silica aerogel blocks with a refractive index

Fig.8. Photo of the AC detector to be used in the FOREST/BLC experiment (left), the supporting block and threads for the radiator placement (upper right), and silica aerogel blocks
used for the radiator (lower right). The photo is taken from the downstream side. The
supporting block is a dummy silica aerogel with a size of 40 × 25 mm3 and a refractive
index of 1.03. The silica aerogel blocks with refractive indices of 1.12 and 1.09 are usedin the low- and high-momentum sides, respectively.

- 88 -

ELPH Annual Report, Tohoku University (2019)of 1.09 for the higher momentum side. Fig. 8(lower right) shows a photo of the silica aerogel blocks usedin the radiator.
The experimental setup was similar to that for the first (second) beam test. Fig. 9 shows the impact
positions of positrons for the light-yield measurement with and without the silica aerogel radiator. The
X and Y axes in the frame of the AC detector were rotated by 90◦ with respect to the z axis in the third
beam test as compared with the first and second tests. The 7 (4) PMTs are placed so that those windows
are at Y = +130 (−130) mm.

Fig.9. Impact positions of positrons for the light yield measurement with (left) and without(right) the silica aerogel radiator. The 7 (4) PMTs are placed so that those windows are
at Y = +130 (−130) mm.
The total light yield was obtained by summing up all the energies in the 11 PMTs. Fig. 10 shows
the light yield as a function of the Y position (corresponding to the distance from the PMT windows). It
does not take a convex downward shape but shows a monotonically increasing behavior. This is because
the number of the PMTs placed at Y = −130 mm was 4, and because Cherenkov photons were notsufficiently collected in these PMTs.
At first, the efficiency was estimated from the total light yield with a fixed threshold value. In thiscase, an efficiency of 98.1% and a mis-identification probability of 4.1% were obtained with a thresholdvalue of 5.5 pe. Fig. 11(left) shows the efficiency and a mis-identification probability as a function of thethreshold for the total light yield. Since the reasonable threshold value of 5.5 pe is too high for the typical light yield. We estimated the efficiency in an alternative way: the detector is considered to respondto a positron when the number of PMTs having higher light yield than 0.5 pe is larger than the threshold number of PMTs. In this case, an efficiency of 98.4% and a mis-identification probability of 2.4%
were obtained with a threshold value of 4. Fig. 11(right) shows the efficiency and a mis-identification
probability as a function of the threshold number of responding PMTs.
Thus far, efficiencies were estimated for the 600-MeV/c positrons with almost the speed of light. The- 89 -

ELPH Annual Report, Tohoku University (2019)

Fig.10. Light yield as a function of the Y position (corresponding to the distance from the PMT
windows). Seven PMTs are placed at Y = +130 mm, and four at Y = −130 mm.

- 90 -

60

99.4
99.2

50

99
40
98.8
30

98.6

eff[%]

98.4

20

98.2

ineff[%]

10

98
97.8

0
0

1

2
3
threshold Npe

4

5

6

threshold for the total light yield

mis-identification probability

70

99.6

ineff[%]

8099.8

efficiency

efficiency

eff[%](0,0)
100

mis-identification probability

ELPH Annual Report, Tohoku University (2019)

threshold for the number of responding PMTs

Fig.11. Efficiency and a mis-identification probability as a function of the threshold for the total
light yield (left), and those as a function of the threshold number of responding PMTs
(left), The red points represent the efficiency for 600-MeV/c positrons with the left vertical axis, and the blue shows the mis-identification probability with the right axis.

light yield for 675-MeV/c pions are 4/5 of that for the 600-MeV/c positrons . Fig. 12 shows the efficiencies
as a function of the Y position for different X positions with a threshold value of 2 pe. Except in theedge region, efficiencies were obtained higher than 97% for 675-MeV/c pions.

Fig.12. Efficiency as a function of the Y position for different X positions with a threshold valueof 2 pe.

§ 4. Summary
We are developing an AC detector for π/K separation fitted to the FOREST/BLC experiment. We
have found that the mirror-type is advantageous over the diffuser-type for guiding a Cherenkov lightto the PMTs. We have constructed the AC detector, and investigated its performance using 600-MeV/cpositrons at ELPH. Silica aerogel blocks with refractive indices of 1.12 and 1.09 have been used in the- 91 -

ELPH Annual Report, Tohoku University (2019)

lower- and higher-momentum side of the radiator. The light yield of 10.4 pe have been obtained at thecenter. And we have obtained efficiencies higher than 97% except in the edge region. The low light yield
was considered to come from using a low index (1.09) aerogel blocks. We will have enough efficiencies by
replacing them with 1.12 ones.

Acknowledgment
The authors express gratitude to the ELPH accelerator staff for stable operation of the accelerators
for testing the AC detector. They acknowledge Mr. Ken’ichi Nanbu, and Mr. Ikuro Nagasawa for theirtechnical assistance. This work was supported in part by the Japan Society for the Promotion of Science(JSPS) through Grants-in-Aid for Scientific Research (B) No. 19H01902, and for Scientific Research on
Innovative Areas Nos. 19H05141 and 19H05181.

References[1]

T.O. Yamamoto et al. (J-PARC E13 collaboration): Phys. Rev. Lett. 115 (2015) 222501.

[2]

A. Esser et al. (A1 collaboration at MAMI): Phys. Rev. Lett. 114 (2015) 232501.

[3]

A. Budzanowski et al. (HIRES collaboration): Phys. Lett. B 687 (2010) 31.

[4]

A. Gasparyan, J. Haidenbauer, C. Hanhart, J. Speth: Phys. Rev. C 69 (2004) 034006.

[5]

A. Gasparyan, J. Haidenbauer, C. Hanhart: Phys. Rev. C 72 (2005) 034006.

[6]

J.T. Balewski et al., Eur. Phys. J. A 2 (1998) 99.

[7]

F. Hinterberger, A. Sibirtsev, Eur. Phys. J. A 21 (2004) 313.

[8]

F.M. Renard, Y. Renard, Nucl. Phys. B 1 (1967) 389.

[9]

B.O. Kerbikov, B.L.G. Bakker, R. Daling: Nucl. Phys. A 480 (1988) 585.

[10] B.O. Kerbikov: Phys. At. Nucl. 64 (2001) 1835.
[11] R.A. Adelseck, L.E. Wright: Phys. Rev. C 39 (1989) 580.
[12] X. Li, L.E. Wright: J. Phys. G 17 (1991) 1127.
[13] H. Yamamura et al., Phys. Rev. C 61 (1999) 014001.
[14] O.V. Maxwell: Phys. Rev. C 69 (2004) 034605.
[15] O.V. Maxwell: Phys. Rev. C 70 (2004) 044612.
[16] A. Salam, H. Arenhövel: Phys. Rev. C 70 (2004) 044008.
[17] K. Miyagawa, T. Mart, C. Bennhold, W. Glöckle: Phys. Rev. C 74 (2006) 034002.
[18] A. Salam, K. Miyagawa, T. Mart, C. Bennhold, W. Glöckle: Phys. Rev. C 74 (2006) 044004.
[19] J.M. Laget: Phys. Rev. C 75 (2007) 014002.
[20] A. Gasparyan et al.: Eur. Phys. J. A 32 (2007) 61.
[21] T. Ishikawa et al.: JPS Conf. Proc. 13 (2016) 020031.
[22] T. Ishikawa et al., Acta Phys. Polon. B 48 (2017) 1801.
[23] S.X. Nakamura, H. Kamano, T. Ishikawa, Phys. Rev. C 96 (2017) 042201 (R).
[24] T. Ishikawa et al.: Nucl. Instrum. and Meth. A 832 (2016) 108.

- 92 -

ELPH Annual Report, Tohoku University (2019)[25] T. Ishikawa et al.: Nucl. Instrum. and Meth. A 694 (2012) 348.
[26] H. Hama, AAPPS Bulletin 30 (2020) 41.

- 93 -

ELPH Annual Report, Tohoku University (2019)- 94 -

ELPH Annual Report, Tohoku University (2019) 

   

                

       !

       ! ! % - *  
 %

%

! !

! !     -

 

.

# 

§ ½º

 ! % !
 
 %


!



!



! "

 !"



& 

.





!

#  !%

§ ¾º



!%

 &&' %!

)%  % *  + ,% % ! + . - / !

" ! %



!

 !

%+ #  

!       !.

. !

!

!"

! %

!

 



! ! + . 

 !

.

(

"

 !

  %

  









  "(!  !  
(2!



!%

!

!  





!"

"  !

! ! - $ 

! 

 



!

!%% !

 !   !

!% 

.! %

  

! % #! ! 
! %

#
 



!


"

  !   &&' %!

 "     % !

 ! .

!%+

" ! %

 ! # %%

  !

!   #

! 

%

(

# 

!(

#  " #%!

! ! ! ! 

% -







# 



! .!

!

 !  .!

  ! !

# ! 



#

!


 ! ! 

! % ! 

" $ !



-

!"
!%

"





1 "- 4- * !%-

  * %
!

# 4
%

!

%

 $    

!  #

" !%

#





% .

 "  !!

 ! !  ! !

  

#-  !

% # &&' %!



!

-

!"

%

 

-

*

 



!

3 !

 !%- 1

 . 

# ! %

/ !

!

"  $! % &! " !  0!

!"!   %  %!  .           

" $ !

  

#



 ½

!

%  !" !

#    

! ! *5 &(6 #- * %!

%    &&' %!

- * %!

 !  " ( &- -   !

&&'()  

 & -  - 

# 68,(94: 8*$/; % - ! < !

!  %!

 !    % 

" %

-

!

 !  7   - 95 -! ! + .  ! 2!  !  !  %+ !  6  

##

 .  !

ELPH Annual Report, Tohoku University (2019)

1 "-4-* !%!

!

- /  %  

μ

)%

!

#



 ! #

#



! !

 %+  ! !% !. 

$ 

%

.!
  -4

%



!

#

 

 =

%%+



%  !" !

 !  #

× 6



  

! %!
! !  #

/

!

 %

!



# ! !

 

#





  



! ! !



 &&'()  !" .  &&'()  

! !

"

#



6



 



  "1 "- - /%+ #

 6!

 !  !
&&'()  !

# %
 

 =

%



!

%

  "

!

!%% !

2!  !  =!

  

# == :0  - )! !  ! 4 μ

4

 





! ! !

 #

#

 !


!

 %+ * "-

1 "--

 

!

!

! !

 7 ! 

    

- * !%% !
/- *

#     - *

- * #!   - * "

 !%


  #! ;! "1 "- 6- *#!  * #    #-- 96 -

 ; #! !  !

 ! !%
 #

6

!%

!  

 #   !

%+ #" ! <% #  ; #4-=    !# .  

#ELPH Annual Report, Tohoku University (2019)

1 "-6-!



# ! !



! 

 &&'()    



 &&'()  -§ ¿º  
*

!"

. !

.

 ;

 @ 

%!

 ! #   !  "( !

#. 

. %

%



 #

"



 .

! "-   

.! % 



1 "->-!. >- :82 

%

 %

   .
. 

%

- * #1 "- >- *


 ;

    "!     !- 3 !  %





γ 

.

.

!?

 %

"!

"



#!

!"

. !

- 97 -  



 ;




 %! ! !  . ! "

  %



 ! 

-

!

!%

. γ %

!%

# 


!

 .  &&'()  -

ELPH Annual Report, Tohoku University (2019)- 98 -

Ⅱ. Status Report

ELPH Annual Report, Tohoku University (2019)

Status of Accelerator Facilities in FY2019
T. Muto, K. Kanomata, S. Kashiwagi, F. Hinode, S. Miura, I.Nagasawa,
K. Nanbu, K. Shibata, K. Takahashi and H. Hama
Accelerator group in ELPH, Tohoku University, Sendai, 982-0826

In FY2019, the total operating time of electron accelerator complex in ELPH; high intensity 60MeV
linac, 90MeV injector linac and 1.3GeV BST (Booster-Storage Ring) and test accelerator t-ACTS,
exceeded 2000 hours. Two large update work was done at the high intensity linac. One was the changing of
the control system’s software in spring. For higher maintainability, the software of control system changed
to EPICS and LabVIEW, which were same software of injector and BST ring control system. Another one
was the replacement of electron gun in summer. The new gun cathode EIMAC Y646-B was widely used
and would be provided for long term. The high intensity linac with the new gun could become to provide
same quality electron beam.

§1. High intensity linac
The high intensity linac can provide the electron beam with repetition rate up to 300Hz and energy rangeof 10-60MeV. The typical beam current is 120A for 50MeV operation. The operating beam time of thehigh intensity linac in FY 2019 exceeded 350 hours.
Upgrade work of control system was carried out on the spring. Pervious control system was made by
Simple Transmission and Retrieval System (STARS)[1] and Visual Basic[2]. New control system wasmade by Experimental Physics and Industrial Control System (EPICS)[3] and LabVIEW[4], which aresame software used on the control system of the injector linac and the BST ring. By using same software oftwo control systems, maintainability would be increased, but human resource for maintenance would be
reduced. However, two control systems are still independent for the rigidity of each accelerator systems anddifferent operation schedule. The window of new control system is shown in Fig.1.

- 99 -

ELPH Annual Report, Tohoku University (2019)

Figure 1 New control window of high intensity linac
In summer shutdown, the update work of the electron gun was done. It had been difficult tomaintenance because of gun cathode was stopped to supply by the manufacturer. New electron gun was
designed to fit the cathode EIMAC Y646-B, which was widely used for the accelerator of sterilization,
and which would be provided by the manufacture for long term. There were some small troubles instaring up, but the replacement work was done. The high intensity linac with the new gun could become
to provide same quality electron beam with beam current 120A (50MeV operation).
A large vacuum leak was happened on beam tuning in October. This leak at flanges near bending
magnet in 1st experimental hall would be caused by heating that the electron beam hit to beam duct. To
monitor this heating, four thermocouples was put on beam duct around leak position. The heating of
beam ducts could be avoided by checking these temperatures and careful beam tuning. There was novacuum leak around bending magnet after this modification.
In December operation, two incidents were occurred. One incident was irradiation to converter without
cooling water. This problem caused by lack of cooling water in reservoir tank. Another one was more
serious. That was vacuum leak at Ti window of beam irradiation system. By the elements analysis of theTi window, Oxygen molecule was detected at leaking position of Ti window (Fig.2). However, Oxygen
molecule was not detected at another part of Ti window (Fig.3). It suggested presence of water in He
circulating by cooling system and some reaction between water and Ti by beam irradiation was occurred.

- 100 -

ELPH Annual Report, Tohoku University (2019)

Figure 2 Elemental distribution of leak position of

Figure 3 Elemental distribution of another part ofTi window. Red circle was Oxygen peak.

Ti window. There was no Oxygen peak.

Both incidents were caused by failure of cooling system which is part of irradiation system. So, theirradiation system was modified. In the water cooling system for the converter, the water level gauge wasadded to reservoir tank to check water level. The He cooling system was simplified and added the dewpoint meter to check water in He. After this modification, cooling system was tested. However, the dewpoint of He was still not enough low. There would be the slow leak of converterʼs cooling water to He
cooling system. To remove the moisture, Molecular Sieve, which is a kind of Zeolite, was installed to He
cooling system. By Molecular Sieve, the dew-point of He system was reduced to enough low. From
February, beam time for users was served.

§2. Injector linac
The injector linac stably supplies an electron beam to the BST ring with 90MeV. However, there is aproblem that discharge of thermionic rf gun was occurred and the gun became unstable in May operation.
This problem already has been occurred few times[5]. It was recovered by replacement of gun cathode.
By the permission of the change request to Nuclear Regulation Authority, new electron beamline could be
operated. This beamline so-called “beamline II” provided 90MeV electron beam direct to experiment areain Accelerator room (Fig.4). In October operation, beamline II provided electron beam to users.

Figure 4 Layout of the Injector linac
The operating time of the injector linac exceeded 1300 hours in FY2019.

§3. BST ring

- 101 -

ELPH Annual Report, Tohoku University (2019)

The 1.3GeV BST ring has well operated to generate high energy gamma rays via bremsstrahlung frominternal target wire inserted to electron orbit. Generated gamma rays are not only utilized to the experiment forquark/hadron physics, but also supplied to the test beam line for testing of detectors used in high energy experiments.
The operating time of the BST ring exceeded to 1250 hours in FY2019.
On long beam time for hadron physics experiment in April and May, the power supply of DC septum was broken andreplaced at three time. In June, the thyratron of kicker in BST ring was replaced.

§4. Test accelerator t-ACTS
The test accelerator as Coherent THz Source (t-ACTS) provided extremely short electron beam withbunch length ~80fs for generation of various radiation as coherent transition radiation (CTR), coherent
undulator radiation and coherent Cherenkov radiation[6]. The operating time of t-ACTS in FY2019
exceeded 350 hours.

References[1] http://stars.kek.jp/[2] https://docs.microsoft.com/ja-jp/dotnet/visual-basic/[3] https://epics-controls.org/[4] https://www.ni.com/ja-jp/shop/labview.html[5] F. Hinode et al., “Status of Accelerator Facilities in FY2018”, ELPH Annual Report, Tohoku University(2018)[6] S. Kahiwagi et al., “STATUS OF TEST-ACCELERATOR AS COHERENT THz SOURCE(t-ACTS) AT ELPH, TOHOKU UNIVERSITY“, proceedings of 10th Int. Particle Accelerator Conf.
(IPAC2019), Melbourne, (2019), 1475-1477- 102 -

ELPH Annual Report, Tohoku University (2019)

User Support Ofﬁce Report in FY2019
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 2019 ﬁnancial year, we had provided the electron, photon and positron beam. But Vacuum
leak problems were occurred several times, we could not provide the beam as planned initially. In May,
October and December 2019, because the failure of the Vacuum leak has occurred, we couldn’t provide
any user beam-time because of the repairing work during these period. In addition, in early December,the electric gun problem has occurred at 70 MeV electric linear accelerator [1, 2].

§ 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, BEAM
LINE I)• Tagged photon beam from 1.3 GeV electron synchrotron called BST ring with 90 MeV injector at
the second irradiation lab (For Hadron Physics, BEAM LINE II, Photon beamline I)• Tagged photon beam at the GeV-γ irradiation room (For Hadron Physics, BEAM LINE III, 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 was used for Hadron physics experiments. NKS2 and FOREST/BLC experiment have bean
held in recent years.

§ 2. Beamtime operated
The total radiation time was 311 hours for the RI linac operation and 1269 hours for the BST
operation, and it was 1580 hours in total. Table 1 summarizes the radiation 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 39 shifts experiments are performed
using this positron beam in this ﬁnancial year.

- 103 -

ELPH Annual Report, Tohoku University (2019)

A Next generation FOREST experiments (FOREST/BLC) was started by GeV-γ group in ELPH.
New bending magnet was installed on the downstream of FOREST detectors and it covers the mostforward angle. These new experimental setup enable the zero degree proton detection for the γd → pηnreaction at Eγ ∼ 0.9 GeV. This reaction gives the zero relative momentum between the η and n. Thissituation will enable to determine the ηn scattering length. In this ﬁnancial year, physical data wastaken with hydrogen and deuteron target. Total 58 shifts of FOREST/BLC experiment(#2894) werecarried out.
In Photon beam line I, New detectors research and developments for NKS2 experiment(#2787) has been
carried out in this ﬁnancial year.
one experiment was carried out for the undergraduate students. This experiment (#2926: H.
Ohnishi, ELPH, Tohoku University) is for the education of the undergraduate students in ELPH [?].
Table 1. Radiation times, and user beamtimes in ﬁnancial year 2019. 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 Ring
radiation (h) radiation (h)
Month
April
0
547
May
19
165
Jun
61
112
July
88
0
August00September
00
October
29
17
November
1
153
December
48
173
January
0
48
February
64
54
March
0
0
Sum
311
1269

§ 3. ELPH workshops and ELPH seminars
In this ﬁscal year, ELPH supported two ELPH workshops. the ﬁrst one is ”SNP school 2019 [4]”(C025: S. N. Nakamura, Tohoku University), The second one is hadron physics ”ハドロン構造における多粒子相関” (C024: D. Jido, Tokyo Institute of Technology). Additionally, 13 ELPH seminars were held inthis ﬁscal year. Seminars title and talker are listed below.
• 前田 幸重, 宮崎大学工学教育研究部工学基礎教育センター, ”少数核子系散乱実験による核力の三体力効果の研究”• 羽島 良一, 量子科学技術研究開発機構, ”レーザー・コンプトン散乱ガンマ線、基礎と応用の間で”• 黒田 直史, 東京大学大学院総合文化研究科広域科学専攻 相関基礎科学系, ”反水素原子ビーム分光による基礎物理研究”• M. Cargnelutti, Instrumentation Technologie, Slovenia, ”An overview of beam diagnostics andreadout electronics for particle accelerators”- 104 -

ELPH Annual Report, Tohoku University (2019)• Vladimir Dubinko, National Science Centre Kharkov Institute of Physics and Technology, ”Nuclear
Fusion of Hydrogen Isotopes Induced by the Localized Anharmonic Vibrations”• Tadeusz LESIAK, Institute of Nuclear Physics of the Polish Academy of Sciences, ”QCD aspects at
future e+ e− colliders at the energy frontier”• Tomasz SKWARNICKI, College of Arts and Sciences at Syracuse University, ”Exotic Baryons”• 浅川 誠, 関西大学, ”低エネルギー電子バンチを用いたスミス・パーセル放射光源の開発”• 齋藤 武彦, 理研、GSI、蘭州大学, ”重イオンビームを用いたストレンジネス原子核研究：HypHI 実験と今後の計画について”• 日野原 伸生, 筑波大学計算科学研究センター, ”二重ベータ崩壊原子核行列要素の核構造計算”• 藤原 守, 大阪大学核物理研究センター, ”Sustainability medical isotope productions of 99m Tc for SPECT
inspection and of 18 F for PET inspection”• 田辺 克明, 京都大学工学研究科, ”凝縮系核融合の研究について”• Michael Famiano, Western Michigan University, United States, ”A Nuclear Physics Explanation of
Biomolecular Homochirality: Theory and Experiment”

References[1]

Beam time schedule 2019A < https://www.lns.tohoku.ac.jp/archives/3250/ >[2]

Beam time schedule 2019B < https://www.lns.tohoku.ac.jp/archives/3635/ >[3]

Approved proposvals < https://www.lns.tohoku.ac.jp/users/saitaku/ >[4]

SNP School 2019 < https://lambda.phys.tohoku.ac.jp/snpsc2019/ >- 105 -

ELPH Annual Report, Tohoku University (2019)- 106 -

ELPH Annual Report, Tohoku University (2019)

Radiation Safety Report 2019
Radiatn Safety Office

放射線安全管理室より 2019 年度（平成 31 年 4 月～令和 2 年度 3 月）の報告を以下の通り行う。

§1. 許認可申請
令和元年 5 月 20 日

承認使用に係る変更承認申請書の提出

令和元年 7 月 18 日

変更の承認

令和元年 8 月 21 日

放射線障害予防規程の改定、変更届の提出

令和 2 年 3 月 2 日

原子力規制庁 立入検査

§2. 個人管理
2.1 放射線業務従事者登録179人（ 東北大 77人

学外 84人

研究者以外 18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

2.3 教育訓練
定期講習（再教育のみ）

令和元年 10月 30日 82人

不定期の講習（規程改正前）（規程改正後）再教育 11回 23人
再教育 12回 21人
変更点の周知 11回

179人

登録前教育（新規教育）9回 21人
登録前教育（新規教育）20回 49人
20人§3. 自主点検
年2回実施

令和元年 9月20日、令和2年3月9日§4. 放射性同位元素製造記録
2019 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とお- 107 -

ELPH Annual Report, Tohoku University (2019)り。
核種

数量 (kBq)

核種

数量 (kBq)

As-74

2

Na-24

5,000

Au-196

1,000

Nb-95

5,000

Ba-131

20

Ni-57

11,010Ba-133m

1

Pm-143100

Ba-135m

2,401

Ra-225

0.24

Ca-47

1,140

Rb-83

2.4

Co-57

1,106

Rb-84

2.4

Cs-132

204

Rb-86

40

Cs-136

2,040

Sc-46

19,000Hg-203

302

Sc-48

1,000

K-42

28,100

Sr-85

180

K-43

143,240

Tl-202

302,000

Mo-99

12,000

V-48

4,000

Na-22

900

Zn-65

2

全 28 核種

計 539793.04 kBq§5. その他
菊永、武藤 受講予定の 2020/3/13 の主任者定期講習が、新型コロナウイルス感染拡大に伴い中止となった- 108 -

Ⅲ. List of Publication

ELPH Annual Report, Tohoku University (2019)

List of Publication (論⽂リスト) (2019)
Papers Published in Refereed Journals
Profile measurement of circulating electrons in a synchrotron by inserting a carbon wire
Y. Obara, T. Ishikawa, H. Hama, F. Hinode, H. Kanda, S. Kashiwagi, M. Miyabe, T. Muto,
K. Ozawa, H. Shimizu, A.O. Tokiyasu
Nucl. Inst. Meth. A 922, p.p. 108-113, (2019).

Light source based on a 100 mm-long monolithic undulator magnet with a very
short 4 mm-period length
S. Yamamoto, S. Kashiwagi, S. Masuda, N. Nakanii, T. Hosokai, M. Kando, T. Muto,
K. - Nanbu, F. Hinode and H. Hama
J. Synchrotron Rad. 26, 1902-1910, (2019).

Performance evaluation of a silicon strip detector for positrons/electrons from a pulsed
a muon beam
T. Aoyagi, Y. Honda, H. Ikeda, M. Ikeno, K. Kawagoe, T. Kohriki, T. Kume, T. Mibe,
K. Namba, S. Nishimura, N. Saito, O. Sasaki, N. Sato, Y. Sato, H. Sendai,
K. Shimomura, S. Shirabe, M. Shoji, T. Suda, T. Suehara, T. Takatomi, M. Tanaka,
J. Tojo, K. Tsukada, T. Uchida, T. Ushizawa, H. Wauke, T. Yamanakand T. Yoshioka
JINST 15(2020) P04027.

Energy of the 229Th Nuclear Clock Isomer Determined by Absolute γ-ray Energy
Difference
A. Yamaguchi, H. Muramatsu, T. Hayashi, N. Yuasa, K. Nakamura, M. Takimoto,
H. Haba, K. Konashi, M. Watanabe, H. Kikunaga, K. Maehata, N. Y. Yamasaki,
K. Mitsuda
Physical Review Letters 123 (2019) 222501

Vertical Migration of Cs-137 in Japanese Orchards after the Fukushima Daiichi
Nuclear Power Plant Accident
M. Sato, K. Matsuoka, T. Takase, NI Kobayshi, H. Kikunaga, D. Tanaka, K.
Tanoi, T. Ohtsuki, S. Kusada, K. Yamaguchi
Horticulture Journal 88 (2019) 150-163- 109 -

ELPH Annual Report, Tohoku University (2019)

Dispersal rates of 225Ac in exhaust, surface, and waste water under chemical
operations
T. Yamamura, K. Shirasaki, H. Kikunaga, K. Nagata, Z. Zhang, K. Washiyama,
A. Toyoshima, T. Yoshimura, A. Shinohara
Radiation Safety Management (accepted)

Synthesis and Photoluminescence of Tetracyanidonitridorhenium(V) Complexes
with Five-membered N-heteroaromatic Ligands and Photoluminescence-intensity
ChangeMoe Seike, Kojiro Nagata, Hayato Ikeda, Akitaka Ito, Eri Sakuda, Noboru
Kitamura, Atsushi Shinohara, Takashi YoshimuraACS Omega, 4 (2019) 21251-21259.

Microvascular Dysfunction Related to Progressive Left Ventricular Remodelingdue to Chronic Occlusion of the Left Anterior Descending Artery in an Adult
Porcine Heart
Shin Yajima, Shigeru Miyagawa, Satsuki Fukushima, Kayako Isohashi, Tadashi
Watabe, Hayato Ikeda, Genki Horitsugi, Akima Harada, Ryoto Sakaniwa, Jun
Hatazawa, Yoshiki Sawa
International Heart Journal 60 (2019) 715–727.

Quantitative measurement of regional cerebral blood flow and oxygen metabolism
in a rat model of cerebral hypoperfusion
Hiroki Kato, Yasukazu Kanai, Tadashi Watabe, Hayato Ikeda, Genki Horitsugi,
Jun Hatazawa
Brain Research 1719, (2019) 208–216.

Distribution of LAT1-targeting PET tracer was independent of the tumor bloodflow in rat xenograft models of C6 glioma and MIA PaCa-2
Masanao Aoki, Tadashi Watabe Shushi Nagamori, Sadahiro Naka, Hayato Ikeda,
Pornparn Kongpracha, Genki Horitsugi, Yasukazu Kanai, Eku Shimosegawa,Yoshikatsu Kanai, Jun Hatazawa
Annals of Nuclear Medicine 33, (2019) 394–403.

Positron tracking detector for J-PARC muon 𝑔−2/EDM experiment- 110 -

ELPH Annual Report, Tohoku University (2019)

T. Yamanaka, T. Aoyagi, H. Ikeda, M. Ikeno, T. Ito, K. Ueno, T. Uchida, K. Kawagoe,
T. Kishishita, T. Kume, T. Kohriki, N. Saito, O. Sasaki, T. Sata, N. Sato, Y. Sato,
M. Shoji, S. Shirabe, T. Suehara, Y. Sue, T. Suda, H. Sendai, T. Takatomi, M. Tanaka,
K. Tsukada, Y. Tsutsumi, J. Tojo, K. Namba, S. Nishimura, Y. Honda, M. Matama,
T. Mibe, T. Murakami, H. Yasuda, and T. Yoshioka
NIMA 958 (2020) 162786.

Future Possibilities for Accelerators in Nuclear Physics
Shoji Nagamiya, Hideto En'yo, Hirokazu Tamura
Review of Accelerator Science and Technology 10 (2019) 13-32

Evidence for potassium transport acitivity of Arabidopsis KEA1-KEA6
Tsujii, M., Kera, K., Hamamoto, S., Kuromori, T., Shikanai, T., and Uozumi, N.
Sci. Rep., 9, 10040 (2019)

The mechanosensitive channel YbdG from Escherichia coil has a role inadaptation to osmotic up-shock
Amemiya, S., Toyoda, H. Kimura, M., Saito, H., Kobayashi, H., hara, K., Kamagata,
K., Kawabata, R., Kato, S., Nakashimada, Y., Furuta, T., Hamamoto, S., and Uozumi, N.
J. Biol. Chem. 294, 12281-12292 (2019)

Guard cell membrane anion transport systems and their regulatory components:
an eleborate mechanism controlling stress-induced stomatal closure
Saito, S. and Uozumi, N.
Plants 8, 9 (2019)

Cesium inhibits plant growth primarily through reduction of potassium influx andaccumulation in Arabidopsis
Adams, E., Miyazaki, T., Saito, S., Uozumi, N. and Shin, R.
Plant Cell Physiol. 60 (1), 63-76 (2019)

DAY-LENGTH-DEPENDENT DELAYED-GREENING1, the Arabidopsis homologof the cyanobacterial H+-extrusion protein, is essential for chloroplast pH
regulation and optimization of non-photochemical quenching
Harada, K., Arizono, T., Sato, R., Trinh, M.D.L., Hashimoto, A., Kono, M., Tsujii,
M., Uozumi, N., Takaichi, S., and Masuda, S.

- 111 -

ELPH Annual Report, Tohoku University (2019)

Plant Cell Physiol. 60 (12), 2660–2671 (2019)

Relativistic corrections to the binding energy of positronic alkali-metal atoms
Takuma Yamashita, Yasushi Kino
Physical Review A, 100 (2019) 062511 (12 pages).

Correlation of Radiocesium Activity between Muscle and Peripheral Blood of Live
Cattle Depending on Presence or Absence of Radiocontamination in Feed
Masatoshi Suzuki, Hidehiko Suzuki, Hirotoshi Ishiguro, Yosuke Saito,
Satoshi Watanabe, Tomoyuki Kozutsumi, Yuichiro Sochi, Kiyoshi Nishi,
Yusuke Urushihara, Yasushi Kino, Takashi Numabe, Tsutomu Sekine,
Koichi Chida, and Manabu Fukumoto
Radiation Research, 192 (2019) 589-601.

Synthesis, structures, redox properties, and theoretical calculations of thiohalide
capped octahedral hexanuclear technetium(III) clusters
Takashi Yoshimura, Kojiro Nagata, Ayumi Matsuda, Toshiki Omote, Yasushi
Kino, Tsutomu Takayama, Tsutomu Sekine and Atsushi Shinohara
Dalton Transactions, 48 (2019) 14085-14095.

Four-body treatment of the antihydrogen-positronium system: binding, structure,resonant states and collisions
Piotr Froelich, Yasushi Kino, Emiko Hiyama, Takuma Yamashita, Konrad Piszczatowski,
Svante Jonsell
Hyperfine Interactions, 240 (2019) 46 (16 pages).

Analysis of Radioactive Elements in Testes of Large Japanese Field Mice Using an
Electron Probe Micro-Analyser after the Fukushima Accident
Takuya Ohdaira, Kanna Meguro, Kazuki Komatsu, Rina Syoji, Yohei Fujishima,
Valerie Swee Ting Goh, Kosuke Kasai, Kentaro Ariyoshi, Akifumi Nakata,
Yusuke Urushihara, Kazuma Koarai, Yasushi Kino, Tsutomu Sekine, Masatoshi Suzuki,
Atsushi Takahasi, Yoshinaka Shimizu, Hisashi Shinoda, Mitsuaki A Yoshida,
Manabu Fukumoto, Hideaki Yamashiro, Tomisato Miura
Ionizing and Non-ionizing Radiation, IntechOpen, UK, (2019) 9 pages- 112 -

ELPH Annual Report, Tohoku University (2019)

Intestinal bacteria as powerful trapping lifeforms for the elimination ofradioactive cesium
Kazuki Saito, Kengo Kuroda, Rie Suzuki, Yasushi Kino, Tsutomu Sekine,
Hisashi Shinoda, Hideaki Yamashiro, Tomokazu Fukuda, Jin Kobayashi, Yasuyuki
Abe, Junko Nishimura, Yusuke Urushihara, Hiroshi Yoneyama,
Manabu Fukumoto, Emiko Isogai
Frontiers in veterinary science, 6 (2019) 70 (8pages)

Time-dependent Hartree-Fock plus Langevin approach for hot fusion reactions tosynthesize the superheavy element with Z=120
K. Sekizawa and K. Hagino
Phys. Rev. C99, 051602(R) (2019) (5 pages).

Potential model for nuclear astrophysical fusion reactions with a square-wellpotential
R. Ogura, K. Hagino, and C.A. Bertulani
Phys. Rev. C99, 065808 (2019) (4 pages).

Sub-barrier fusion involving odd mass nuclei: the case of 36S+50Ti,51V
G. Colucci, G. Montagnoli, A.M. Stefanini, K. Hagino, A. Caciolli, P. Colovic, L. Corradi,
E. Fioretto, F. Galtarossa, A. Goasdu, J. Grebosz, M. Mazzocco, D. Montanari,
C. Parascandolo, F. Scarlassara, M. Siciliano, E. Strano, S. Szilner and N. Vukman
Euro. Phys. J. A55, 111 (2019) (6 pages).

Dissipation and tunneling in heavy-ion reactions near the Coulomb barrier
E. Piasecki, M. Kowalczyk, S. Yusa, A. Trzcinska, and K. Hagino
Phys. Rev. C100, 014616 (2019) (11 pages)
ラザフォードの指導を受けた日本人若手研究者―S. Obaとは誰か
萩野浩一、小林良彦、豊田直樹、中村哲
日本物理学会誌 74(9), 655-658 (2019).

Subbarrier fusion reactions of an aligned deformed nucleus
K. Hagino and S. Sakaguchi
Phys. Rev. C100, 064614 (2019) (6 pages).

- 113 -

ELPH Annual Report, Tohoku University (2019)

A new approach for open quantum systems based on a phonon number
representation of a harmonic oscillator bath
M. Tokieda and K. Hagino
Ann. of Phys. 412, 168005 (2020) (29 pages).

Constraining the 12C+12C astrophysical S-factors with the 12C+13C measurements
at very low Energies
N.T. Zhang, X.Y. Wang, H. Chen, Z.J. Chen, W.P. Lin, X.D. Tang, W.Y. Xin, S.W. Xu,
D. Tudor, A.I. Chilug, I.C. Stefanescu, M. Straticiuc, I. Burducea, D.G. Ghita,
R. Margineanu, C. Gomoiu, A. Pantelica, D. Chesneanu, L. Trache, B. Bucher,
L.R. Gasques, K. Hagino, S. Kubono, Y.J. Li, C.J. Lin, A.S. Umar, and Y. Xu
Phys. Lett. B801, 135170 (2020) (5 pages).

Resonance width for a particle-core coupling model with a square-well potential
K. Hagino, H. Sagawa, S. Kanaya, and A. Odahara
Prog. Theo. Exp. Phys. 2000, 023D01 (2020) (19 pages).

Time-dependent approaches to open quantum systems
M. Tokieda and K. Hagino
Frontiers Phys. 8, 8 (2020) (8 pages).

Fusion Dynamics for Hot Fusion Reactions to Synthesize Superheavy Nuclei
revealed in Quasielastic Barrier Distributions
T. Tanaka, K. Morita, K. Morimoto, D. Kaji, H. Haba, R.A. Boll, N. T. Brewer,
S. Van Cleve, D.J. Dean, S. Ishizawa, Y. Ito, Y. Komori, K. Nishio, T. Niwase, B.C. Rasco,
J.B. Roberto, K.P. Rykaczewski, H. Sakai, D.W. Stracener, and K. Hagino
Phys. Rev. Lett. 124, 052502 (2020) (6 pages).

An overview of the scientific contribution of Andrea Vitturi to Nuclear Physics
L. Fortunato, C.E. Alonso, J.M. Arias, J. Casal, K. Hagino, J.A. Lay, E.G. Lanza,
S.M. Lenzi, J. Lubian, T. Oishi, F. Perez-Bernal
Euro. Phys. J. A56, 49 (2020) (25 pages).

Image-processing the topological charge density in the CP(N-1) model
Y. Abe, K. Fukushima, Y. Hidaka, H. Matsueda, K. Murase and S. Sasaki.
Prog. Theor. Exp. Phys. (2020) 013D02.

- 114 -

ELPH Annual Report, Tohoku University (2019)

Hadron Physics at J-PARC
Hiroaki Ohnishi, Fuminori Sakuma and Toshiyuki Takahashi
Prog.Part.Nucl.Phys. (2020) 103773

Measurement of neutral pion photoproduction off the proton with the large
acceptance electromagnetic calorimeter BGOegg
N. Muramatsu, J. K. Ahn, W. C. Chang, J. Y. Chen, M. L. Chu, S. Daté, T. Gogami,
H. Goto, H. Hamano, T. Hashimoto, 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, M. Miyabe, K. Mizutani, T. Nakamura,
T. Nakano, T. Nam, T. N. T. Ngan, M. Niiyama, Y. Nozawa, Y. Ohashi, H. Ohnishi,
T. Ohta, K. Ozawa, C. Rangacharyulu, S. Y. Ryu, Y. Sada, M. Sasagawa, T. Shibukawa,
H. Shimizu, R. Shirai, K. Shiraishi, E. A. Strokovsky, Y. Sugaya, M. Sumihama,
S. Suzuki, S. Tanaka, A. Tokiyasu, N. Tomida, Y. Tsuchikawa, T. Ueda, H. Yamazaki,
R. Yamazaki, Y. Yanai, T. Yorita, C. Yoshida, and M. Yosoi
Phys. Rev. C 100(2019), 055202

Nuclear dependence of light neutral meson production in p-A collisions at 400 GeV
with NA60
R. Arnaldi, K. Banicz, K. Borer, J. Castor, B. Chaurand, W. Chen, C. Cicalò, A. Colla,
P. Cortese, S. Damjanovic, A. David, A. De Falco, A. Devaux, L. Ducroux, H. En’yo,
J. Fargeix, A. Ferretti, M. Floris, A. Förster, P. Force, N. Guettet, A. Guichard,
H. Gulkanian, J. M. Heuser, P. Jarron, M. Keil, L. Kluberg, Z. Li, C. Lourenço,
J. Lozano, F. Manso, P. Martins, A. Masoni, A. Neves, H. Ohnishi, C. Oppedisano,P. Parracho, P. Pillot, T. Poghosyan, G. Puddu, E. Radermacher, P. Ramalhete,
P. Rosinsky, E. Scomparin, J. Seixas, S. Serci, R. Shahoyan, P. Sonderegger,
H. J. Specht, R. Tieulent, A. Uras, G. Usai, R. Veenhof, H. K. Wöhri
Eur.Phys.J.C 79 (2019) 5, 443

Position tracking detector for J-PARC muon g-2/EDM experiment
T. Yamanaka, T. Aoyagi, H. Ikeda, M.Ikeno, T.Ito, K.Ueno,, T.Uchida, K.Kawagoe,
T.Kishishita, T.Kume, T.Kohriki, N.Saito, O.Sasaki, T.Sata, N.Sato, Y.Sato, M.Shoji,
S.Shirabe, T.Suehara, Y.Sue, T.Suda, H.Sendai, T.Takatomi, M.Tanaka, K.Tsukada,
Y.Tsutsumi, J.Tojo, K.Namba, S.Nishimura, Y.Honda, M.Matama,
T. Mibe, T. Murakami, H. Yasuda, T. Yoshioka- 115 -

ELPH Annual Report, Tohoku University (2019)

Nuclear Instruments and Methods in Physics A958 (2020) 162786

Recent Progress and Prospects of the LEPS2/BGOegg Experiment at SPring-8
N. Muramatsu for the LEPS2/BGOegg Collaboration
Acta Physica Polonica B 51 No.1 (2020) 231‒238.

Non-strange dibaryons studied in the γd→π0π0d reaction
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, H.Y. Yoshida.
Phys. Lett. B 789, 413 (2019).

ηN Scattering Parameters and Possible η'd Bound State from η Photoproduction
on the Deuteron
T. Ishikawa, K. Aoki, H. Fujimura, H. Fukasawa, H. Fujioka, R. Hashimoto, Q. He, Y.
Honda, T. Hotta, Y. Inoue, K. Itahashi, T. Iwata, S. Kaida, H. Kanda, J. Kasagi,
A. Kawano, S. Kusawaki, H. Kawai, K. Maeda, S. Masumoto, Y. Matsumura,
M. Miyabe, F. Miyahara, K. Mochizuki, S. Miyata, N. Muramatsu, A. Nakamura,
K. Nawa, T. Nishi, S. Ohgushi, Y. Okada, H. Ohnishi, Y. Onodera, K. Ozawa,
Y. Sakamoto, M. Sato, H. Shimizu, H. Sugai, K. Suzuki, R. Shirai, M. Tabata,Y. Tajima, S. Takahashi, Y. Taniguchi, A.O. Tokiyasu, Y. Tsuchikawa, H. Yamazaki,
R. Yamazaki, C. Yoshida, H.Y. Yoshida
Acta Phys.Polon.B 51 (2020) 27-32"K-pp", a Kbar-meson nuclear bound state, observed in 3He(K-, Λp)n reactions
J-PARC E15 collaboration, S. Ajimura, H. Asano, G. Beer, C. Berucci, H. Bhang,
M. Bragadireanu, P. Buehler, L. Busso, M. Cargnelli, S. Choi, C. Curceanu, S. Enomoto,
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, K. Itahashi, M. Iwasaki,
K. Kanno, K. Kato, 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,
Y. Sada, A. Sakaguchi, 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, T. Yamaga,- 116 -

ELPH Annual Report, Tohoku University (2019)

T. Yamazaki, Q. Zhang, J. Zmeskal
Physics Letters B 789 (2019) 620-625.

Proton form factor ratio 𝝁𝒑 𝑮𝒑𝑬 /𝑮𝒑𝑴 from double spin asymmetry
A. Liyanage, W. Armstrong, H. Kang, J. Maxwell, J. Mulholland, L. Ndukum,
A. Ahmidouch, I. Albayrak, A. Asaturyan, O. Ates, H. Baghdasaryan, W. Boeglin,
P. Bosted, E. Brash, C. Butuceanu,M. Bychkov, P. Carter, C. Chen, J.-P. Chen, S. Choi,
E. Christy, S. Covrig, D. Crabb, S. Danagoulian, A. Daniel, A. M. Davidenko, B. Davis,
D. Day, W. Deconinck, A. Deur, J. Dunne, D. Dutta, L. El Fassi, M. Elaasar, C. Ellis,
R. Ent, D. Flay, E. Frlez, D. Gaskell, O. Geagla, J. German, R. Gilman, T. Gogami,
J. Gomez, Y. M. Goncharenko, O. Hashimoto, D. Higinbotham, T. Horn, G. M. Huber,
M. Jones, M. K. Jones, N. Kalantarians, H.-K. Kang, D. Kawama, C. Keppel,
M. Khandaker, Y. Kim, P. M. King, M. Kohl, K. Kovacs, V. Kubarovsky, Y. Li,
N. Liyanage, V. Mamyan, P. Markowitz, T. Maruta, Y. M. Melnik, Z.-E. Meziani,
A. Mkrtchyan, H. Mkrtchyan, V. V. Mochalov, P. Monaghan, A. Narayan, S. N. Nakamura,Nuruzzaman, L. Pentchev, D. Pocanic, M. Posik, A. Puckett, X. Qiu, J. Reinhold,S. Riordan, J. Roche, O. A. Rondón, B. Sawatzky, M. Shabestari, K. Slifer, G. Smith,
L. F. Soloviev, P. Solvignon, V. Tadevosyan, L. Tang, A. N. Vasiliev, M. Veilleux,
T. Walton, F. Wesselmann, S. A. Wood, H. Yao, Z. Ye, and L. Zhu (SANE Collaboration)
Physical Review C 101(2020) 035206-1-12

Decay pion spectroscopy: A new approach
A.Margaryan, R.Ajvazyan, N.Grigoryan, V.Kakoyan, V.Khachatryan, H.Vardanyan,
S.Zhamkochyan, P.Achenbach, J.Pochodzalla, S.N.Nakamura, S.Nagao, Y.Toyama,
J.R.M.Annand, K.Livingston, R.Montgomery
Nucl. Inst. and Meth. A 935 (2019) 40-50

Search for 𝑲𝑳 → 𝝅𝟎 𝝂𝝂 and 𝑲𝑳 → 𝝅𝟎 𝑿𝟎 Decays at the J-PARC KOTO ExperimentJ. K. Ahn, B. Beckford, J. Beechert, K. Bryant, M. Campbell, S. H. Chen, J. Comfort,
K. Dona, N. Hara, H. Haraguchi, Y. B. Hsiung, M. Hutcheson, T. Inagaki, I. Kamiji,
N. Kawasaki, E. J. Kim, J. L. Kim, Y. J. Kim, J. W. Ko, T. K. Komatsubara, K. Kotera,
A. S. Kurilin, J. W. Lee, G. Y. Lim, C. Lin, Q. Lin, Y. Luo, J. Ma, Y. Maeda, T. Mari,
T. Masuda, T. Matsumura, D. Mcfarland, N. McNeal, J. Micallef, K. Miyazaki,
R. Murayama, D. Naito, K. Nakagiri, H. Nanjo, H. Nishimiya, T. Nomura, M. Ohsugi,
H. Okuno, M. Sasaki, N. Sasao, K. Sato, T. Sato, Y. Sato, H. Schamis, S. Seki,- 117 -

ELPH Annual Report, Tohoku University (2019)

N. Shimizu, T. Shimogawa, T. Shinkawa, S. Shinohara, K. Shiomi, S. Su, Y. Sugiyama,
S. Suzuki, Y. Tajima, M. Taylor, M. Tecchio, M. Togawa, Y. C. Tung, Y. W. Wah,
H. Watanabe, J. K. Woo, T. Yamanaka, and H. Y. Yoshida
Phys. Rev. Lett. 122, (2019) 021802 1-6Proﬁle measurement of circulating electrons in a synchrotron by inserting a carbon wire
Y. Obara, T. Ishikawa, H. Hama, F. Hinode, H. Kanda, S. Kashiwagi, M. Miyabe, T. Muto,
K. Ozawa, H. Shimizu, A.O. Tokiyasu
Nucl. Instr. Meth. A922 (2019) 108.

Anomalous Heat Effects Induced by Metal Nano-composites and Hydrogen Gas
Y. Iwamura, T. Itoh, J. Kasagi, A. Kitamura, A. Takahashi, K. Takahashi, R. Seto, T. Hatano,
T. Hioki, T. Motohiro, M. Nakamura, M. Uchimura, H. Takahashi, S. Sumitomo,
Y. Furuyama. M. Kishida and H. Matsune,
J. Condensed Matter Nucl. Sci. 29 (2019) 119–128.

Papers Published in Conference Proceedings, Books etc.
Characteristics of Polarized Coherent Radiation in THz Region from a Crossed
Undulator
H. Saito, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, N.M.
Morita, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, K. Takahashi, H. Yamada
10th Int. Particle Accelerator Conf. (IPAC'19), Melbourne, 1769-1771, (2019).

Status of Test-Accelerator as Coherent THz Source at ELPH, Tohoku University
S. Kashiwagi, H. Hama, F. Hinode, K. Kanomata, S. Miura, N.M. Morita, T. Muto,
I. Nagasawa, K. Nanbu, S. Ninomiya, H. Saito, K. Takahashi, H. Yamada
10th Int. Particle Accelerator Conf. (IPAC2019), Melbourne, 1475-1477, (2019).

Measurement of Cherenkov Diffraction Radiation from Short Electron Bunches at
t-ACTS
S. Ninomiya, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, N.M. Morita,
T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Takahashi, H. Yamada
10th Int. Particle Accelerator Conf. (IPAC'19), Melbourne, 2536-2538, (2019).

Crossed-Undulator Configuration for Variable Polarized THz Source- 118 -

ELPH Annual Report, Tohoku University (2019)

H. Saito, H. Hama, S. Kashiwagi, N.M. Morita, T. Muto, K. Nanbu, H. Yamada
39th Free Electron Laser Conf. (FEL2019), Hamburg, Germany, 69-72, (2019).
コヒーレントスミス=パーセル放射を用いた非破壊型バンチ長モニターの研究
山田 悠樹，日出 富士雄，柏木 茂，武藤 俊哉，三浦 禎雄，南部 健一，髙橋 健，
長澤 育郎，鹿又 健，齊藤 寛峻，森田 希望，濱 広幸
日本加速器学会 第16回年会プロシーディングス, (2019), 40-42

交叉型アンジュレータにおける移相器の設計と開発
森田 希望，柏木 茂，日出 富士夫，三浦 禎雄，武藤 俊哉，南部 健一，長澤 育郎，髙橋 健，鹿又 健，柴田 晃太郎，齋藤 寛峻，山田悠樹，濱 広幸

日本加速器学会 第16回年会プロシーディングス, (2019), 157-160

極短周期アンジュレータの開発と光源性能評価試験
山本 樹，益田 伸一，浜 広幸，柏木 茂，日出 富士雄，武藤 俊哉，南部 健一
日本加速器学会 第16回年会プロシーディングス, (2019), 170-174

交叉型アンジュレータからのTHz域コヒーレント放射の偏光特性(II)齊藤 寛峻，柏木 茂，日出 富士雄，三浦 禎雄，武藤 俊哉，南部 健一，長澤 育郎，髙橋 健，鹿又 健，柴田 晃太朗，森田 希望，山田 悠樹，石附 勇人，
寺田 健人，濱 広幸
日本加速器学会 第16回年会プロシーディングス, (2019), 445-448

テラヘルツコヒーレントアンジュレータ放射の偏光制御
柏木 茂，齊藤 寛峻，全 炳俊，入澤 明典，日出 富士雄，武藤 俊哉，森田 希望，
山田 悠樹，南部 健一，鹿又 健，髙橋 健，長澤 育郎，柴田 晃太朗，三浦 禎雄，
濱 広幸
日本加速器学会 第16回年会プロシーディングス, (2019), 747-750
t-ACTSにおける中空誘電体からのチェレンコフ光の測定
南部 健一，日出 富士雄，柏木 茂，武藤 俊哉，齊藤 寛峻，森田 希望，山田 悠樹，鹿又 健，髙橋 健，長澤 育郎，柴田 晃太朗，三浦 禎雄，濱 広幸
日本加速器学会 第16回年会プロシーディングス, (2019), 1122-1124

東北大学電子光理学研究センター加速器群の現状
日出 富士雄，柏木 茂，鹿又 健，柴崎 義信，柴田 晃太朗，髙橋 健，長澤 育郎，- 119 -

ELPH Annual Report, Tohoku University (2019)南部 健一，三浦 禎雄，武藤 俊哉，濱 広幸
日本加速器学会 第16回年会プロシーディングス, (2019), 1279-1281

Λ(1405) Spectroscopy via the In-flight d(K−, n) Reaction at the J-PARC K1.8BR
Shingo Kawasaki, Shu Aikawa, Shuhei Ajimura, Takaya Akaishi, Hidemitsu Asano,George Beer, Carolina Berruci, Mario Bragadireanu, Paul Buehler, Luigi Busso,
Michael Cargnelli, Seonho Choi, Catalina Curceanu, Shun Enomoto, Hiroyuki Fujioka ,Yuya Fujiwara, Tomokazu Fukuda, Carlo Guaraldo, Tadashi Hashimoto,
Ryugo S. Hayano, Toshihiko Hiraiwa, Masami Iio, Mihai Iliescu, Kentaro Inoue,
Yosuke Ishiguro, Takashi Ishikawa, Shigeru Ishimoto, Kenta Itahashi, Masaaki Iwai,
Masahiko Iwasaki, Koki Kanno, Kazuma Kato, Yuko Kato, Paul Kienle, Yusuke Komatsu,
Hirofumi Kou, Yue Ma, Johann Marton, Yasuyuki Matsuda, Yutaka Mizoi,
Ombretta Morra, Tomofumi Nagae, Hiroyuki Noumi, Hiroaki Ohnishi, Shinji Okada,
Zhadyra Omar, Haruhiko Outa, Kristian Piscicchia, Yuta Sada, Atsushi Sakaguchi,
Fuminori Sakuma, Masaharu Sato, Alessandro Scordo, Michiko Sekimoto, Hexi Shi,
Kotaro Shirotori, Diana Sirghi, Florin Sirghi, Ken Suzuki, Shoji Suzuki, Takatoshi Suzuki,
Kiyoshi Tanida, Hideyuki Tatsuno, Atsushi O. Tokiyasu, Makoto Tokuda, Dai Tomono,
Akihisa Toyoda, Kyo Tsukada, Oton Vazquez Doce, Eberhard Widmann, Takumi Yamaga,
Toshimitsu Yamazaki, Heejoong Yim, Qi Zhang, and Johann Zmeskal
JPS Conf. Proc. 26 (2019) 022009

Results of KbarNN Search via the (K−,n) Reaction at J-PARC
Takumi Yamaga, Shuhei Ajimura, Hidemitsu Asano, George Beer, Carolina Berruci,
Hyeongchan Bhang, Mario Bragadireanu, Paul Buehler, Luigi Busso, Michael Cargnelli,
Seonho Choi, Catalina Curceanu, Shun Enomoto, Hiroyuki Fujioka, Yuya Fujiwara,
Tomokazu Fukuda, Carlo Guaraldo, Tadashi Hashimoto, Ryugo S. Hayano,
Toshihiko Hiraiwa, Masami Iio, Mihai Iliescu, Kentaro Inoue, Yosuke Ishiguro,
Takashi Ishikawa, Shigeru Ishimoto, Kenta Itahashi, Masahiko Iwasaki, Koki Kanno,
Kazuma Kato, Yuko Kato, Shingo Kawasaki, Paul Kienle, Hirofumi Kou, Yue Ma,
Johann Marton, Yasuyuki Matsuda, Yutaka Mizoi, Ombretta Morra, Tomofumi Nagae,
Hiroyuki Noumi, Hiroaki Ohnishi, Shinji Okada, Haruhiko Outa, Kristian Piscicchia,
Yuta Sada, Atsushi Sakaguchi, Fuminori Sakuma, Masaharu Sato, Alessandro Scordo,
Michiko Sekimoto, Hexi Shi, Kotaro Shirotori, Diana Sirghi, Florin Sirghi, Ken Suzuki,
Shoji Suzuki, Takatoshi Suzuki, Kiyoshi Tanida, Hideyuki Tatsuno, Makoto Tokuda,
Dai Tomono, Akihisa Toyoda, Kyo Tsukada, Oton Vazquez Doce, Eberhard Widmann,
Toshimitsu Yamazaki, Qi Zhang, and Johann Zmeskal- 120 -

ELPH Annual Report, Tohoku University (2019)

JPS Conf. Proc. 26 (2019) 023008

Kaonic Atom Experiments at J-PARC
T. Hashimoto, S. Aikawa, S. Ajimura, T. Akaishi, H. Asano, M. Bazzi, G. Beer,
D. Bennett, C. Berucci, D. Bosnar, M. Bragadireanu, P. Bhler, L. Busso, A. D. Butt,
M. Cargnelli, Seonho Choi, C. Curceanu, W. B. Doriese, M. S. Durkin, S. Enomoto,Y. Ezoe, J. W. Fowler, H. Fujioka, T. Fukuda, C. Guaraldo, F. P. Gustafsson, C. Han,
R. Hayakawa, R. S. Hayano, T. Hayashi, J. P. Hays-Wehle, G. C. Hilton, T. Hiraiwa,
Y. Ichinohe, M. Iio, Y. Iizawa, M. Iliescu, K. Inoue, S. Ishimoto, Y. Ishisaki, K. Itahashi,
M. Iwasaki, S. Kawasaki, Y. Ma4, J. Marton, Y. Matsuda, Y. Mizoi, O. Morra,
T. Murakami, T. Nagae, T. Nishi, H. Noda, H. Noumi, K. Nunomura, G. C. OʼNeil,
T. Ohashi, H. Ohnishi, S. Okada, H. Outa, K. Piscicchia, C. D. Reintsema, Y. Sada,
A. Sakaguchi, F. Sakuma, M. Sato, D. R. Schmidt, A. Scordo, M. Sekimoto, H. Shi,
K. Shirotori, D. Sirghi, F. Sirghi, K. Suzuki, S. Suzuki, T. Suzuki, D. S. Swetz,
A. Takamine, K. Tanida, H. Tatsuno, D. Tomono, A. Toyoda, C. Trippl, K. Tsukada,J. Uhlig, J. N. Ullom, O. Vazquez Doce, E. Widmann, S. Yamada, T. Yamaga,
T. Yamazaki, and J. Zmeskal
JPS Conf. Proc. 26 (2019) 023013

Electron scattering from 208Pb and 132Xe ions at the SCRIT facility
Kyo Tsukada, Kousuke Adachi, Akitomo Enokizono, Takahiro Fujita, Masahiro Hara,
Toshitada Hori, Mitsuki Hori, Shin-ichi Ichikawa, Keita Kasama, Kazuyoshi Kurita,
Kazuki Namba, Tetsuya Ohnishi, Toshimi Suda, Tadaaki Tamae, Mamoru Togasaki,
Masanori Wakasugi, Masamitsu Watanabe, Kouhei Yamada
Hyperfine Interact. 240 (2019) 1, 102

Spectroscopic study of the Λ(1405) resonance via the d(K−,n) reaction at J-PARC
H. Asano, S. Aikawa, S. Ajimura, T. Akaishi, G. Beer, C. Berucci, M. Bragadireanu,
P. Buehler, L. Busso, M. Cargnelli, S. Choi, C. Curceanu, S. Enomoto, 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, K. Itahashi, M. Iwai,
M. Iwasaki, K. Kanno, K. Kato, Y. Kato, S. Kawasaki, P. Kienle, Y. Komatsu,
H. Kou, Y. Ma, J. Marton, Y. Matsuda, Y. Mizoi, O. Morra, T. Nagae, H. Noumi,
H. Ohnishi, S. Okada, Z. Omar, H. Outa, K. Piscicchia, Y. Sada, A. Sakaguchi,
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, A. O. Tokiyasu, M. Tokuda,- 121 -

ELPH Annual Report, Tohoku University (2019)

D. Tomono, A. Toyoda, K. Tsukada, O. Vazquez Doce, E. Widmann, T. Yamaga,
T. Yamazaki, H. Yim, Q. Zhang, and J. Zmeskal
AIP Conf. Proc. 2130 (2019) 1, 0400183

Spectroscopy of pionic atoms in 122Sn(d,3He) reaction and angular dependence of theformation cross sections
T. Nishi, K. Itahashi, G. P. A. Berg, H. Fujioka, N. Fukuda, N. Fukunishi, H. Geissel,
R. S. Hayano, S. Hirenzaki, K. Ichikawa, N. Ikeno, N. Inabe, S. Itoh, M. Iwasaki,
D. Kameda, S. Kawase, T. Kubo, K. Kusaka, H. Matsubara, S. Michimasa, K. Miki,
G. Mishima, H. Miya, H. Nagahiro, M. Nakamura, S. Noji, K. Okochi, S. Ota,
N. Sakamoto, K. Suzuki, H. Takeda, Y. K. Tanaka, K. Todoroki, K. Tsukada, T. Uesaka,
Y. N. Watanabe, H. Weick, H. Yamakami, and K. Yoshida
RIKEN Accel. Prog. Rep. 52 (2019) 91

Precise magnetic field measurement of WiSES
H. Wauke, A. Enokizono, Y. Honda, K. Sasama, T. Ohnishi, T. Suda, S. Takayama, T.
Tamae, K. Tsukada, M. Wakasugi, and M. Watanabe
RIKEN Accel. Prog. Rep. 52 (2019) 145

Design of an Ion Source for the eSHE project Toward Pioneering Electron Scatteringon Superheavy Elements
S. Naimi, T. K. Sato, K. Tsukada, P. Schury, Y. Ito, H. Haba, Y. Komori, T. Ohnishi,
and T. Uesaka
RIKEN Accel. Prog. Rep. 52 (2019) 151

Status of Accelerator Facilities in FY2018
F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K.
Nanbu,
Y. Shibasaki, K. Takahashi and H. Hama
ELPH Annual Report, Tohoku University (2018), 129-133

Development of simultaneous production method for carrier-free RI multitracer ofpotassium, rubidium and cesium
H. Ikeda, H. Kikunaga, H. Watabe
ELPH Annual Report 2018 (2019) 116–119.

- 122 -

ELPH Annual Report, Tohoku University (2019)

Column chromatography of astatine using weak base anion exchange resin
H. Ikeda, H. Kikunaga, Y. Komori, T. Yokokita, D. Mori, H. Haba, and H. Watabe
RIKEN Accelerator Progress Report 2018 Vol. 52 (2019) 203.

Production of arsenic RI tracer from gallium oxide target by alpha beam irradiation
H. Ikeda, H. Kikunaga, Y. Komori, T. Yokokita, D. Mori, H. Haba, and H. Watabe
RIKEN Accelerator Progress Report 2018 Vol. 52 (2019) 206.

Cold Fusion : Advances in Condensed Matter
J. Kasagi, Y. Honda and K. Fang,
Nuclear Science (Elsevier Inc., 2020), pp 167-187.

Present status and prospect of nuclear physics with strangeness—summary of
HYP2018
H. Tamura
Proc. 13th International Conference on Hypernuclear and Strange Particle Physics(HYP 2018), AIP Conference Proceedings 2130 (2019) 60001

Observation of a  bound state in the 12C(K−,K+) reaction at 1.8 GeV/c
T. Nagae et al.
Proc. 13th International Conference on Hypernuclear and Strange Particle Physics(HYP 2018), AIP Conference Proceedings 2130 (2019) 20015

Kbar and nucleus system studied by 12C(K−,p) spectrum
Y. Ichikawa et al.
Proc. 13th International Conference on Hypernuclear and Strange Particle Physics(HYP 2018), AIP Conference Proceedings 2130 (2019) 40017

Σp scattering experiment at J-PARC – results of commissioning run
K. Miwa et al.
Proc. 13th International Conference on Hypernuclear and Strange Particle Physics(HYP 2018), AIP Conference Proceedings 2130 (2019) 20006

Strangeness Nuclear Physics
H. Tamura
Proc. 8th International Conference on Quarks and Nuclear Physics (QNP2018),- 123 -

ELPH Annual Report, Tohoku University (2019)

JPS Conference Proceedings 26 (2019) 11003

First γ-Ray Spectroscopy of an sd-Shell Hypernucleus, 19ΛF
S.B. Yang et al.
Proc. 8th International Conference on Quarks and Nuclear Physics (QNP2018),
JPS Conference Proceedings 26 (22019) 23015

Study of Y* in Nuclei through C(K-,π+)X Spectrum at 1.8 GeV/c in the J-PARC E05
ExperimentR. Honda et al.
Proc. 8th International Conference on Quarks and Nuclear Physics (QNP2018),
JPS Conference Proceedings 26 (2019) 23014

Status of the J-PARC E07, Systematic Study of Double Strangeness Nuclei with theHybrid Emulsion Method
J. Yoshida et al.
Proc. 8th International Conference on Quarks and Nuclear Physics (QNP2018),
JPS Conference Proceedings 26 (2019) 23006

A Σp scattering Experiment at J-PARC and the Analysis Status
Y. Nakada et al.
Proc. 8th International Conference on Quarks and Nuclear Physics (QNP2018),
JPS Conference Proceedings 26 (2019) 23024

The  - Atom X-ray Spectroscopy at J-PARC
M. Fujita et al.
Proc. 8th International Conference on Quarks and Nuclear Physics (QNP2018),
JPS Conference Proceedings 26 (2019) 31016

Operation of Multi-MPPC System for Cylindrical Scintillation Fiber Tracker
Y. Akazawa et al.
Proc. 5th International Workshop on New Photon Detectors (PD18),
JPS Conference Proceedings 27 (2019) 011008
基礎科学で未来をつくる―科学的意義と社会的意義
田村裕和、村山斉、櫻井博儀、常田佐久、前野悦輝、岡本拓司、中村幸司、梶田隆章- 124 -

ELPH Annual Report, Tohoku University (2019)

丸善出版、 2019.

微生物TRPチャネルの機能と役割
魚住信之，山下敦子
TRPチャネルのすべて 医学のあゆみ 270巻10号 医歯薬出版 (2019)

Muon catalyzed fusion, present and future
Atsuo Iiyoshi, Yasushi Kino, Motoyasu Sato, Yoshiharu Tanahashi, Norimasa Yamamoto,Shin Nakatani, Takuma Yamashita, Michael Tendler, Osamu Motojima
AIP Conference Proceedings 2179 (2019) 020010 (7 pages)
キノコ栽培用木材の放射性および安定セシウム濃度測定
田巻廣明、木野康志、村野井友、板橋康弘、中島丈博、郡山慎一、木村栄一、鴨原隆
KEK Proceedings of the 20th Workshop on Environmental Radioactivity, 2019 (2019)120-125
福島原発事故後のウシ、サルの硬組織への環境中からの90Srの移行
小荒井一真, 木野康志、小野拓実、岡壽崇、高橋温、鈴木敏彦、清水良央、千葉美麗、
小坂健、佐々木啓一、鈴木正敏、漆原佑介、福田智一、磯貝恵美子、関根勉、篠田壽、
福本学
KEK Proceedings of the 20th Workshop on Environmental Radioactivity, 2019 (2019)183-188
福島第一原発事故影響調査のための野生動物体内の放射性核種分布と被ばく線量の評価
小野拓実、小荒井一真, 木野康志、田巻廣明、岡壽崇、高橋温、鈴木敏彦、清水良央、千葉美麗、藤嶋洋平、Varerie Goh Swee Ting、有吉健太郎、中田章史、鈴木正敏、山城秀昭、福本学、関根勉、篠田壽、三浦富智
KEK Proceedings of the 20th Workshop on Environmental Radioactivity, 2019 (2019)
189-194
自生キノコの放射能測定による環境汚染調査
木野康志
東北大学大学院理学研究科・理学部技術「平成30年度技術部報告」(2019) 11-16
2018年に採取された自生キノコの放射能の動向
木野康志- 125 -

ELPH Annual Report, Tohoku University (2019)仙台キノコ同好会会誌 43 (2019) 24-34

Fusion barrier distribution and superheavy elements
K. Hagino and T. Tanaka
J. of Phys. Conf. Ser. 1291, 012010 (2019) (7 pages).

A report on outreach activities at the Research Center for Electron Photon Science(ELPH),
H. Ohnishi,
ELPH annual report 2018

Development for the resistive plate chamber (RPC)
Y. Ishizuki, J. Takahashi, D. Taki K. Terada and H. Ohnishi,
ELPH annual report 2018
BL07Aを利用した軟X線の逆コンプトン散乱による高エネルギーガンマ線生成
村松 憲仁, 岡部 雅大, 鈴木 伸介, 伊達 伸, 清水 肇, 大熊 春夫, 神田 一浩,
宮本 修治, 原田 哲男, 渡邊 健夫, 宮部 学, 時安 敦史
ニュースバルシンポジウム2020 (2020) 76.

Recent results of SPring-8 LEPS2/ BGOegg experimentN. Muramatsu, T. Hashimoto, Y. Matsumura, M. Miyabe, T. Nam, H. Shimizu, N.
Tomida, J.K. Ahn, W.C. Chang, J.Y. Chen, S. Daté, T. Gogami, H. Hamano, Q.H. He,
K. Hicks, T. Hiraiwa, Y. Honda, T. Hotta, Y. Inoue, T. Ishikawa, I. Jaegle, J.M. Jo, Y.
Kasamatsu, H. Katsuragawa, S. Kido, Y. Kon, S. Masumoto, K. Miki, K. Mizutani, T.
Nakamura, T. Nakano, M. Niiyama, Y. Nozawa, Y. Ohashi, H. Ohkuma, H. Ohnishi, T.
Ohta, M. Oka, M. Okabe, K. Ozawa, C. Rangacharyulu, Y. Sada, M. Sasagawa, T.
Shibukawa, R. Shirai, K. Shiraishi, E.A. Strokovsky, Y. Sugaya, M. Sumihama, S. Suzuki,
S. Tanaka, A. Tokiyasu, Y. Tsuchikawa, T. Ueda, H. Yamazaki, R. Yamazaki, Y. Yanai,
T. Yorita, C. Yoshida, and M. Yosoi
ELPH Annual Report 2018 (2019) 89‒96.

Production of a high energy  beam via inverse Compton scattering of soft x-rays froma short undulator- 126 -

ELPH Annual Report, Tohoku University (2019)

Norihito Muramatsu, Masahiro Okabe, Shinsuke Suzuki, Schin Daté, Hajime Shimizu,
Haruo Ohkuma, Kazuhiro Kanda, Shuji Miyamoto, Tetsuo Harada, Takeo Watanabe,
Manabu Miyabe, and Atsushi Tokiyasu
ELPH Annual Report 2018 (2019) 97‒101.

Development of Multilayer Mirror for Producing a Next-generation Photon Beam
Masahiro Okabe, Norihito Muramatsu, and Isamu Ishikawa
ELPH Annual Report 2018 (2019) 102‒104.

石川貴嗣、笠木治郎太、最近の研究から「光子ビームで探るクォーク・グルーオン多体系―ダイバリオンの発見から分光へ」、日本物理学会誌 BUTSURI 第75巻第1号、 22～27 (2020)

Development of a beam timing detector for the charmed baryon spectroscopy
T. Akaishi, T. Aramaki, H. Asano, C.-Y. Chang, W.-C. Chang, R. Honda, Y. Igarashi,
T. Ishikawa, S. Kajikawa, Y. Ma, K. Nagai , H. Noumi, A. Sakaguchi, H. Sako,
K. Shirotori, T.N. Takahashi for the J-PARC E50 collaboration
RCNP Annual Report 2018, Research Center for Nuclear Physics, Osaka
University, p. 1-3, 2019.

Development of Prototype for the Streaming Data Acquisition System of theCharmed Baryon Spectroscopy at J-PARC
T.N. Takahashi, H. Asano, T. Akaishi, T. Aramaki, M. Chang, W.-C. Chang,
R. Honda, Y. Igarashi, T. Ishikawa, S. Kajikawa4 , Y. Ma, K. Nagai, H. Noumi,
H. Sako, and K. Shirotori
RCNP Annual Report 2018, Research Center for Nuclear Physics, Osaka University,p. 1-2, 2019.

ωN Scattering Length from ω Photoproduction on the Proton near theThresholdT. Ishikawa, H. Fujimura, H. Fukasawa, R. Hashimoto, Q. He, Y. Honda, A. Hosaka,
T. Iwata, S. Kaida, J. Kasagi, A. Kawano, S. Kuwasaki, K. Maeda, S. Masumoto, M. Miyabe,
F. Miyahara, K. Mochizuki, N. Muramatsu, A. Nakamura, S.X. Nakamura, K. Nawa,
S. Ogushi, Y. Okada, K. Okamura, Y. Onodera, K. Ozawa, Y. Sakamoto, M. Sato, T. Sato,
H. Shimizu, H. Sugai, K. Suzuki, Y. Tajima, S. Takahashi, Y. Taniguchi, Y. Tsuchikawa,
H. Yamazaki, R. Yamazaki, and H.Y. Yoshida- 127 -

ELPH Annual Report, Tohoku University (2019)

ELPH Annual Report 2018, Research Center for Electron Photon Science, Tohoku
University, p. 5-9, 2019.

Study of dibaryons via γd→π0π0d at Eγ=0.75–1.15 GeV (II)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, S. Takahashi, Y. Taniguchi, Y. Tsuchikawa, H.
Yamazaki, R. Yamazaki, and H.Y. Yoshida
ELPH Annual Report 2018, Research Center for Electron Photon Science, Tohoku
University, p. 10-12, 2019.

Current status of the FOREST/BLC experiments at ELPH
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, H. Shimizu, R. Shirai, M. Tabata, A.O. Tokiyasu, Y. Tsuchikawa,
H. Yamazaki, and C. Yoshida
ELPH Annual Report 2018, Research Center for Electron Photon Science, Tohoku
University, p. 13-17, 2019.

Profile measurement of circulating electrons in a synchrotron using an internal radiator
Y. Obara, T. Ishikawa, H. Hama, F. Hinode, H. Kanda, S. Kashiwagi, M. Miyabe, T. Muto,
K. Ozawa, H. Shimizu, and A.O. Tokiyasu
ELPH Annual Report 2018, Research Center for Electron Photon Science, Tohoku
University, p. 18-21, 2019.

Performance evaluation of a scintillating fiber detector for the high-momentum
secondary beamline at J-PARC
T. Aramaki, T. Akaishi, H. Asano, C.-Y. Chang, W.-C. Chang, R. Honda, Y. Igarashi,
T. Ishikawa, S. Kajikawa, Y. Ma, K. Nagai, H. Noumi, H. Sako, K. Shirotori, T.N.
Takahashi, and for the J-PARC E50 collaboration
ELPH Annual Report 2018, Research Center for Electron Photon Science, Tohoku
University, p. 44-57, 2019.

Development of a beam-timing detector for the charmed-baryon s
pectroscopy experiment at J-PARC 58- 128 -

ELPH Annual Report, Tohoku University (2019)

T. Akaishi, T. Aramaki, H. Asano, C.-Y. Chang, W.-C. Chang, R. Honda, Y. Igarashi,
T. Ishikawa, S. Kajikawa, Y. Ma, K. Nagai, H. Noumi, A. Sakaguchi, H. Sako, K. Shirotori,
T.N. Takahashi, and for the J-PARC E50 collaboration
ELPH Annual Report 2018, Research Center for Electron Photon Science, Tohoku
University, p. 58-65, 2019.

Spectroscopy of electro-produced hypernuclei at JLab
S.N.Nakamura,
AIP Conference Proceedings 2130, 020012 (2019)

Studying Λ interactions in nuclear matter with the 208Pb(e,e′K+)208 ΛTl reaction
F. Garibaldi, O. Benhar, P. Bydžovský S. Covrig, T. Gogami, P. E. C. Markowitz,
D. J. Millener, S. N. Nakamura, J. Reinhold, L. Tang, G. M. Urciuoli, and I. Vidana.,
AIP Conference Proceedings 2130, 040003 (2019).
物理科学,この1年 2020
電子で作って探る“奇妙な”原子核：最強電子線施設JLabにおけるハイパー核電磁生成分光)中村哲 （パリティ編集委員会編）
丸善出版 2020年1月 (ISBN: 9784621304860)

ラザフォードの指導を受けた日本人若手研究者---S.Obaとは誰か
萩野浩一, 小林良彦, 豊田直樹, 中村哲
日本物理学会誌 74(9) 655 - 658 2019年9月

Proceedings of the 8th International Conference on Quarks and Nuclear Physics(QNP2018)
Editors; A.Dote, Y.Goto, A.JHosaka, S.Kumano, A.Monnai, O.Morimatsu,
S.N.Nakamura, M.Naruki, H.Noumi, S.Sawada
JPS Conference Proceedings Vol. 26 (2020) Feb.

Status of n interaction study via the final state interaction effect in  d → K+n
production
Masashi Kaneta for the NKS2 collaboration
JPS Conf. Proc. 26 (2019) 023017-1 - 023017-4
DOI: 10.7566/JPSCP.26.023017- 129 -

ELPH Annual Report, Tohoku University (2019)

Status of a Lifetime Measurement of Light Hypernuclei Using High Intensity
Tagged Photon Beam at ELPH
Y. Toyama, T. Gogami, K. Itabashi, H. Kanda, Y. Konishi, K. Maeda, S. Nagao,
S.N. Nakamura, K. Uehara, and M. Kaneta.
JPS Conference Proceedings, 26 (2019) 031018.

Search for Excited State of 4ΣHe Hypernucleus in the J-PARC E13 Experiment
M. Nakagawa, M. Agnello, Y. Akazawa, N. Amano, K. Aoki, E. Botta, N. Chiga, H. Ekawa,
P. Evtoukhovitch, A. Feliciello, M. Fujita, T. Gogami, S. Hasegawa, S.H. Hayakawa,
T. Hayakawa, R. Honda, K. Hosomi, S. Hwang, N. Ichige, Y. Ichikawa, M. Ikeda, K. Imai,
S. Ishimoto, S. Kanatsuki, M. Kim, S. Kim, S. Kinbara, T. Koike, J. Lee, S. Marcello7,
K. Miwa, T. Moon, T. Nagae, S. Nagao, Y. Nakada, Y. Ogura, A. Sakaguchi, H. Sako,
Y. Sasaki, S. Sato, T. Shiozaki, K. Shirotori, H. Sugimura, S. Suto, S. Suzuki,
T. Takahashi, H. Tamura, K. Tanabe, K. Tanida, Z. Tsamalaidze, M. Ukai,
T.O. Yamamoto, Y. Yamamoto, and S. Yang.
JPS Conference Proceedings, 26 (2019) 023005.

Gamma-ray spectroscopy of single Λ-hypernuclei at J-PARC: Results andperspective
T. Koike, M. Agnello, J.K. Ahn, Y. Akazawa, N. Amano, K. Aoki, E. Botta, N. Chiga,
H. Ekawa, P. Evtoukhovitch, A. Feliciello, M. Fujita, T. Gogami, S. Hasegawa,S. H. Hayakawa, T. Hayakawa, R. Honda, K. Hosomi, S.H. Hwang, N. Ichige,
Y. Ichikawa, M. Ikeda, K. Imai, S. Ishimoto, S. Kanatsuki, M.H. Kim, S.H. Kim,
S. Kinbara, K. Kobayashi, J.Y. Lee, S. Marcello, K. Miwa, T.J. Moon, T. Nagae,
S. Nagao, Y. Nakada, M. Nakagawa, Y. Ogura, A. Sakaguchi, H. Sako, Y. Sasaki,
S. Sato, T. Shiozaki, K. Shirotori, H. Sugimura, S. Suto, S. Suzuki, T. Takahashi, H.
Tamura, K. Tanabe, K. Tanida, Y. Togawa, Z. Tsamalaidze, M. Ukai, T.F. Wang,
T.O. Yamamoto, and S.B. YangAIP Conference Proceedings, 2130 (2019) 020011.

Non-strange Dibaryon Resonances Observed in Coherent Double Neutral-Pion
Photoproduction on the Deuteron
Takatsugu Ishikawa, Hisako Fujimura, Hiroshi Fukasawa, Ryo Hashimoto, Qinghua He,
Yuki Honda, Takahiro Iwata, Shun Kaida, Hiroki Kanda, Jirohta Kasagi, Atsushi Kawano,
Shuzo Kuwasaki, Kazushige Maeda, Shin’ichi Masumoto, Manabu Miyabe,- 130 -

ELPH Annual Report, Tohoku University (2019)

Fusashi Miyahara, Kei’ichi Mochizuki, Norihito Muramatsu, Akihiko Nakamura,
Ken’ichi Nawa, Shoei Ogushi, Yasuyuki Okada, Yoshihito Onodera, Kyoichiro Ozawa,
Yasunobu Sakamoto, Mamoru Sato, Hajime Shimizu, Hiroyuki Sugai, Koutaku Suzuki,
Yasuhisa Tajima, Shin’ichiro Takahashi, Yusuke Taniguchi, Yusuke Tsuchikawa,
Hirohito Yamazaki, Ryuji Yamazaki, and Hiroshi Y. Yoshida (FOREST collaboration)
JPS Conference Proceedings 26, 022014 (2019).

Measuring Space-Time Properties of the Δ(1232) via Bose-Einstein Correlations
Qinghua HE, Hisako FUJIMURA, Hiroshi FUKASAWA, Ryo HASHIMOTO, Yuki HONDA,
Takatsugu ISHIKAWA, Takahiro IWATA, Shun KAIDA, Hiroki KANDA, Jirohta KASAGI,
Atsushi KAWANO, Shuzo KUWASAKI, Kazushige MAEDA, Shinichi MASUMOTO,
Manabu MIYABE, Fusashi MIYAHARA, Keiichi MOCHIZUKI, Norihito MURAMATSU,
Akihiko NAKAMURA, Kenichi NAWA, Shoei OGUSHI, Yasuyuki OKADA, Yoshihito
ONODERA, Kyoichiro OZAWA, Yasunobu SAKAMOTO, Mamoru SATO, Hajime SHIMIZU,
Hiroyuki SUGAI, Koutaku SUZUKI, Yasuhisa TAJIMA, Shinichiro TAKAHASHI,
Yusuke TANIGUCHI, Yusuke TSUCHIKAWA, Hirohito YAMAZAKI, Ryuji YAMAZAKI,
Hiroshi Y. YOSHIDA (FOREST collaboration)
JPS Conference Proceedings 26, 024004 (2019).

Non-strange dibaryons studied in coherent double neutral-meson photoproduction on
the deuteron
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,
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
Acta Physica Polonica B 51, 329-332 (2020).

Performance of the FOREST/BLC Spectrometer for Study of the η-nucleon Interaction
via the γd→pηn Reaction
S. Miyata, K. Aoki, H. Fujioka, Y. Honda, T. Hotta, T. Ishikawa, K. Itahashi, H. Kanda,
H. Kawai, K. Maeda, M. Miyabe, Y. Matsumura, N. Muramatsu, H. Ohnishi, K. Ozawa,
H. Shimizu, M. Tabata, A.O. Tokiyasu, Y. Tsuchikawa, T. Ueda, C. Yoshida
Springer Proceedings in Physics 238, 705-708 (2020).

- 131 -

ELPH Annual Report, Tohoku University (2019)

Study of Non-strange Dibaryon Resonances Via Coherent Double Neutral-Meson
Photoproduction from the Deuteron
T. Ishikawa, H. Fujimura, H. Fukasawa, R. Hashimoto, Q. He, Y. Honda, T. Iwata, S. Kaida,
H. Kanda, 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,
S. Takahashi, Y. Taniguchi, Y. Tsuchikawa, H. Yamazaki, R. Yamazaki, H.Y. Yoshida
Springer Proceedings in Physics 238, 609-613 (2020).

Electromagnetic calorimeter BGOegg for quark nuclear physics
H. Shimizu (LEPS2/BGOegg Collaboration)
KEK Proceedings 2019-4 (December 2019) pp. 51-63.
軟X線を用いた逆コンプトン散乱による高エネルギーガンマ線ビームの開発
村松憲仁、岡部雅大、鈴木伸介、伊達伸、清水肇、大熊春夫、神田一浩、宮本修治、
原田哲男、渡邊健夫、宮部学、時安敦史「加速器」Vol.16, No.3, 2019 (154-160).

Review of permeation-induced nuclear transmutation reactions
Yasuhiro. Iwamura

Cold Fusion: Advances in Condensed Matter Nuclear Science, Ed. Jean-Paul
Biberian, Elsevier, Amsterdam, (2020)191-204.

Heat generation experiments using nano-sized metal composite and hydrogen gas
Yasuhiro Iwamura

Cold Fusion: Advances in Condensed Matter Nuclear Science, Ed. Jean-Paul
Biberian, Elsevier, Amsterdam, (2020)157-165.

Overview of Condensed Matter Nuclear Reaction Division
Yasuhiro Iwamura
ELPH annual report 2018, (2019) 3-4.
光子ビームで探るクォーク・グルーオン多体系～ダイバリオンの発見から分光へ

石川貴嗣、笠木治郎太
日本物理学会誌、第 75 巻第 1 号、 pp. 22 - 26 (2020)- 132 -

ELPH Annual Report, Tohoku University (2019)

Screening Energy for Low Energy Nuclear Reactions in Condensed Matter
J. Kasagi, Y. Honda, K. Fang
“Cold Fusion -Advances in Condensed Matter Nuclear Science-” (Elsevier Inc.,
2020), pp 167-187.

Study of silicon sensors for precise timing measurement
Y. Deguchi, K. Kawagoe, R. Mori, E. Mestre, T. Suehara and T. Yoshioka:
2020 JINST 15 C05051

Study of Position Sensitive Silicon Detector (PSD) for SiW-ECAL at ILC
Y. Uesugi, R. Mori, H. Yamashiro, T. Suehara, T. Yoshioka, K. Kawagoe
2020 JINST 15 C05033

Invited Talk, Oral, and Poster Presentations at International Conferences
Crossed-Undulator Configuration for Variable Polarized THz Source
H. Hama
39th Free Electron Laser Conf. (FEL2019), 25 ‒ 30 August, 2019, Hamburg,
Germany.

Designing work of a compact 3 GeV light source employing multi-bend lattice (Invited
talk)
Hiroyuki Hama
National Synchrotron Radiation Laboratory, University of Science and Technology ofChina, 12th November, 2019, Hefei, China.

Superconducting Electron Accelerators for Various Applications (Invited talk)Hiroyuki Hama
Int. Conf. on Radiation and Emission in Materials 2019, 18th December, 2019,
Bangkok, Thailand.

Demonstration of variable polarized coherent terahertz source (Poster presentation)
S. Kashiwagi, H. Saito, F. Hinode, Y. Ishizuki, K. Kanomata, S. Miura, N. Morita, T.
Muto, I. Nagasawa, K. Nanbu, K. Shibata, K. Takahashi, H. Hama, H. Zen and A.
Irizawa- 133 -

ELPH Annual Report, Tohoku University (2019)

The 10th International Workshop on Infrared Microscopy and Spectroscopy withAccelerator Based Sources, WIRMS 201923-27 September, 2019 Campinas & Ubatuba, Brazil

Measurement of Cherenkov Diffraction Radiation from Short Electron Bunches at
t-ACTS,
F. Hinode
10th Int. Particle Accelerator Conference, Melbourne (Australia), May 19-24,
2019, (Poster)“Proton Charge Radius by Low-Energy Electron Scattering”
T. SudaInternational workshop on the structure of the proton, Yamagata, Feb. 10-11,（招待講演）“Nuclear Physics with low-energy and high-intensity electron beam”
T. SudaNeutrino Nuclear Response 2019 (NNR19), RCNP, Osaka, May 8-9, (口頭発表)“Electron Scattering for Short-Live Nuclei”
T. SudaGordon Conference on “Exploring simple structural patterns and dynamics ofnuclei” June 16-21, New London US, （招待講演）“Nuclear Physics with Electron Beam”
T. SudaConnecting Fundamental Physics, Chemistry and the Origins of Biomolecular
Homochirarity, June 26-27, National Observatory of Japan, （招待講演）“Electron scattering for short-lived nuclei”
T. SudaInternational Nuclear Physics Conference 2019, July 29-Au. 2, Glasgow UK,(Plenary talk)“Proton Radius”
T. Suda- 134 -

ELPH Annual Report, Tohoku University (2019)

The 11th Circum-Pan-Pacific Symposium on High Energy Spin Physics, Aug. 2730, Miyazaki, （招待講演）“Proton Radius”
T. Suda14th Asia-Pacific Physics Conference, Nov. 17-22, Kuching Malyasia, （招待講演）“Electron-scattering activities in Japan for nucleon and nuclei”
T. SudaKVI seminar, Jan. 8, KVI Groningen, Netherlands, （招待講演）“ULQ2 project”
T. SudaCollaborative Seminar by REIMEI, RCNP and Clusters, Feb. 20, （招待講演）

Present status and prospects of the SCRIT electron scattering facility
K. Tsukada
The 9th International Symposium on Nuclear Symmetry Energy (NuSYM2019)
Danang City, Vietnam, Sept. 30 to Oct. 4, 2019 (一般講演)

Present status of SCRIT electron scattering facility
K. Tsukada
The 14th Asia-Pacific Physics Conference (APPC2019)
Kuching, Malaysia, 17 Nov. to 22 Nov., 2019 (一般講演)

Elastic electron-proton scattering with low-energy electron beam at ELPH.
Y. Honda
HU physics colloquium, Hampton, USA, April 25, 2019.（招待講演）

Status of Nuclear Physics in Japan -- Future Projects -H. Tamura
ANPHA 2019 Symposium, Jeju, Korea, June 28-29, 2019（招待講演）

Hypernuclear Physics – Recent Results and Future Prospects
H. Tamura- 135 -

ELPH Annual Report, Tohoku University (2019)

Symposium on Rare Isotope Sciences, Institute for Basic Science, Daejeon, Korea,
July 10, 2019（招待講演）

Hypernuclear Physics -- How to Solve the Hyperon Puzzle -H. Tamura
International Symposium on Nuclear Symmetry Energy (NuSYM2019),
Da Nan, Vietnam, Sept. 30 - Oct. 4, 2019

（招待講演）

J-PARC Heavy Ion Project
H. Tamura
THEIA-STRONG2020 workshop 2019,
Speyer, Germany, November 25-29, 2019（招待講演）

Hypernuclear Physics at J-PARC
H. Tamura
THEIA-STRONG2020 workshop 2019,
Speyer, Germany, November 25-29, 2019

Status and perspective of hypernuclear physics at J-PARC
H. Tamura
3rd EMMI Workshop: Anti-matter, hyper-matter and exotica production at the
LHC
Wroclaw, Poland, December 2-6, 2019（招待講演）

Possible Modification of a Hyperon in Hypernuclei
H. Tamura
STRANEX: Recent progress and perspectives in STRANge EXotic atoms studies
and related topics
ECT*, Trento, Italy, Oct. 21-25, 2019

Experimental studies on possible modification of baryons in nuclei
H. TamuraInternational symposium on Clustering as a Window on the Hierarchical
Structure of Quantum Systems (CLUSHIQ2020)
Beppu, Japan, Jan. 23-24, 2020

- 136 -

ELPH Annual Report, Tohoku University (2019)

Elucidation of the mechanism of Na+ and Cs+-induced cell growth through cationtransporters
Nobuyuki Uozumi, Masaru Tsujii, Ellen Tanudjaja and Kota Kera
18th International Workshop on Plant Membrane Biology, July 7-12, Glasgow UK

Energy levels and stabilities of muonic molecule in muon catalyzed fusion
Yasushi Kino
15th International Conference of Computational Methods in Sciences andEngineering (ICCMSE 2019), Rhodes, Greece, 2019/5/1-5. (Invited talk)

Reaction dynamics for hot fusion reactions with a deformed nucleus
K. Hagino
The 4th International Symposium on Superheavy Elements (SHE2019)・箱根・
2019 年 12 月 1-5 日

Perspectives on nuclear reaction theory and superheavy elements superheavy
regions
K. Hagino
Workshop on nuclear physics and nuclear astrophysics・Soongsil大学・2020 年 1 月 15日

φ meson in nucleus
H. Ohnishi
STRANEX: Recent progress and prespectives in STRANge Exotic atoms studies
and related topics, 10/21-25/2019, ECT*, Trento, Italy [招待講演]

Hadron Physics with anti-proton at J-PARC
H. Ohnishi
E50 DAQ Meeting, 5/17/2019, Institute of Physics, Academia Sinica, 台湾 [招待講演]

Recent Progress and Prospects of the LEPS2/BGOegg Experiment at SPring-8
N. Muramatsu
3rd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics,
Jagiellonian Univ., Krakow, Poland, June 23–28, 2019 (招待講演).

- 137 -

ELPH Annual Report, Tohoku University (2019)

Production of a coherent bremsstrahlung photon beam with several tens of GeV at
ILC
N. Muramatsu
International Workshop on Future Linear Colliders (LCWS 2019), Sendai, Oct. 28– Nov. 1, 2019 (口頭発表).

ωN scattering length from ω photoproduction on the proton near the threshold,T. Ishikawa
The 15th International Conference on Meson-Nucleon Physics and the Structureof the Nucleon, MENU2019, Cohon University Center, Carnegie Mellon
University, Pittsburgh Pennsylvania, USA, Jun. 2-7, 2019, 口頭発表

Non-Strange Dibaryons studied in coherent double neutral-meson
photoproduction on the deuteron
T. Ishikawa
The 12th Internal workshop on the Physics of Excited Nucleons (NSTAR2019),
Poppelsdof Campus, Bonn University, Bonn, Germany, Jun 10-14, 2019, 口頭発表

ηN scattering parameters and possible η'N bound state from η photoproduction on
the deuteron
T. Ishikawa
3rd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics,
Krakow, Poland, Jun. 23-28, 2019, 招待講演

Non-strange dibaryons studied in coherent double neutral-meson photoproduction
on the deuteron
T. Ishikawa
3rd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics,
Krakow, Poland, Jun. 23-28, 2019, ポスター発表

ωN scattering length from ω photoproduction on the proton near the threshold,T. Ishikawa
The 14th Asia-Pacific Physics Conference 2019 (APPC2019), Borneo Convention
Center Kuching, Sarawak, Malaysia, Nov. 17-22, 2019, 口頭発表

Photo-production of the eta-meson on the deuteron,- 138 -

ELPH Annual Report, Tohoku University (2019)

T. Ishikawa
International Symposium on Clustering as a Window on the Hierarchical
Structure of Quantum Systems (CLUSHIQ2020), Beppu, Jan 23-24, 2020、ポスター発表

Dibaryon photoproduction on the deuteron detecting two neutral pions and deuteron,
T. Ishikawa
KEK/Tokai Internal workshop on “Physics of heavy-quark and exotic hadrons”,
KEK-Tokai Campus, Tokai, Jan 26-28, 2020、招待講演

Ideas of Kaonicnuclei search at LEPS
A. O. Tokiyasu
Kaon Physics at DAΦNE, J-PARC @ RIKEN, and SPring-8, Dec. 19th (招待講演)

Axion Search Experiment:Past, present, and future
A. O. Tokiyasu
KMI seminar @ Nagoya University, May 13th, 2019 (招待講演)

Study of the phi meson bound state in nucleus in J-PARC K1.8BR beamline
Y. SadaInternational symposium on Clustering as a Window on the Hierarchical Structureof Quantum Systems (CLUSHIQ2020), Beppu, Oita, Japan, January 23-24 (ポスター)Strangeness Nuclear Physics with Electron/Photon Beams,
S.N.Nakamura
THEIA-STRONG2020-Workshop2019, Speyer, Germany 2019.11.25 (口頭発表)

Status of Experiment for n Interaction Measurement via Final State Interaction in d→ K+n Production
Masashi Kaneta for the NKS2 collaboration
The 14th Asia-Pacific Physics Conference 2019 (APPC14)
2019/11/17-22 招待講演

Design of New Particle Charge Separation Magnet
S. Nagao- 139 -

ELPH Annual Report, Tohoku University (2019)

International meeting for electron beam spectroscopy of Λ hypernuclei: nnΛ analysis(JLab E12-17-003), Kyoto, Japan, May 24 (一般公演)

Precision Spectroscopy of Lambda Hypernuclei with Electro-photo production
S. Nagao
3rd EMMI Workshop, Wrocław, Poland, December 5 (招待講演)

Overview of lifetime measurements on hyper-hydrogens at ELPH Tohoku
S. Nagao
Workshop on electro- and photo-production of hypernuclei 2020, Prague, Czech, February
16 (一般公演)

Design & Construction of new separation magnets for the next hypernuclear experiment
S. Nagao
JLab Hall-A meeting, Newport News, USA, March 3

Excess Energy Generation using a Nano-sized Multilayer Metal Composite andHydrogen Gas
Y. Iwamura, T. Itoh, S. Murakami, Mari Saito and J Kasagi,
22nd International Conference on Condensed Matter Nuclear Science; ICCF-22
Hotel and Conference Centre Domus Pacis, Assisi, Italy, September 8-13, 2019.
(⼝頭発表)

Possible radiation from thin film metal surface with anomalous excess heat:
Can we observe hot spots or Bremsstrahlung?
J. Kasagi
The 22nd International Conference on Condensed Matter Nuclear Science ICCF22,
Assisi, Italy, September 9-13, 2019 (口頭発表)"Precise magnetic field measurement of electron spectrometer for the electron
scattering off unstable nuclei experiment"、
Hikari Wauke (M2)International school for Strangeness Nuclear Physics 2019、東北大学、2019.09.0508、ポスターセッション、SNP School Incentive Prize 受賞- 140 -

ELPH Annual Report, Tohoku University (2019)

Development of an aerogel Cherenkov counter for the LEPS2 solenoid experiment at
SPring-8
Chihiro Yoshida、International Symposium on Clustering as a Window on the Hierarchical
Structure of Quantum Systems (CLUSHIQ2020)、別府、2020/1/23 - 2020/1/24、ポスター

Study of silicon sensors for precise timing measurement
Y. Deguchi, K. Kawagoe, R. Mori, E. Mestre, T. Suehara and T. Yoshioka:
Calorimetry for High Energy Frontier (CHEF2019), Nov. 2019, Fukuoka, Japan

Study of Position Sensitive Silicon Detector (PSD) for SiW-ECAL at ILC
Y. Uesugi, R. Mori, H. Yamashiro, T. Suehara, T. Yoshioka, K. Kawagoe
Calorimetry for High Energy Frontier (CHEF2019), Nov. 2019, Fukuoka, Japan

Time Projection Chamber “HypTPC” for the hadron spectroscopy at J-PARC
Y. Ichikawa for the J-PARC E42, E45, E72 Collaborations,
J-PARC Symposium 2019, Tsukuba, Japan, 2019 Sept.

学位論文（センター内）
修士（理学）岡部 雅大「軟X線の逆コンプトン散乱による高エネルギー光子ビームの開発」（指導教員：大西 宏明）
森田 希望「低エネルギー極短電子パルスのビーム輸送におけるバンチ伸長に関する研究」（指導教員：濱 広幸）
山田 悠樹「極短電子ビームによるコヒーレントスミス=パーセル放射の研究」（指導教員：濱 広幸）
竹屋 匡皓「金属-水素ガス系における異常発熱測定のためのフローカロリーメータの詳細テスト」（指導教員：菊永英寿、笠木治郎太）
和宇慶 ひかり- 141 -

ELPH Annual Report, Tohoku University (2019)「SCRIT電子スペクトロメータの3次元磁場測定」（指導教員：須田 利美）

学位論文（センター外）
修士論文
東 大起（東北大学・工）「植物カリウム吸収・移行を調節する輸送体KUP/HAKの機能解析」（指導教員：魚住 信之）
出口 遊斗, 2019年度九州大学修士学位論文「国際リニアコライダーにおける粒子識別精度向上のための高時間分解能シリコンセンサー開発に向けた研究」（指導教員: 末原大幹 (主査: 川越清以)）
上杉 悠人, 2019年度九州大学修士学位論文「国際リニアコライダーのための高位置分解能シリコンセンサーの開発」（指導教員: 末原大幹 (主査: 川越清以)）- 142 -

Ⅳ. Members of Committees

ELPH Annual Report, Tohoku University (2019)

Steering Committee
2019
HAMA Hiroyuki*

ELPH

SUDA Toshimi

ELPH

OHNISHI Hiroaki

ELPH

HINODE Fujio

ELPH

KASHIWAGI Shigeru

ELPH

MURAMATSU Norihito

ELPH

KIKUNAGA Hidetoshi

ELPH

TAMURA Hirokazu

Graduate School of Science

NAKAMURA Satoshi

Graduate School of Science

HAGINO Kouichi

Graduate School of Science

SASAKI Shoichi

Graduate School of Science

MISAIZU Fuminori

Graduate School of Science

KINO Yasushi

Graduate School of Science

UOZUMI Nobuyuki

Graduate School of Engineering

MATSUYAMA Shigeo

Graduate School of Engineering

KASADA Ryuta

Institute for Materials Research

TAKAKUWA Yuji

Institute of Multidisciplinary Research for Advanced Materials

EJIMA Takeo

Institute of Multidisciplinary Research for Advanced Materials

EDAMATSU Keiichi

Research Institute of Electrical Communication

ITOH Masatoshi

Cyclotron and Radioisotope Center

TSUDA Kenji

Frontier Research Institute for Interdisciplinary Sciences* Chairperson- 143 -

ELPH Annual Report, Tohoku University (2019)

General Advisory Committee
2019
HAMA Hiroyuki*

ELPH, Tohoku University

SUDA Toshimi

ELPH, Tohoku University

OHNISHI Hiroaki

ELPH, Tohoku University

KIKUNAGA Hidetoshi

ELPH, Tohoku University

TAMURA Hirokazu

Graduate School of Science, Tohoku University

KINO Yasushi

Graduate School of Science, Tohoku University

ITOH Masatoshi

Cyclotron and Radioisotope Center, Tohoku University

TSUDA Kenji

Frontier Research Institute for Interdisciplinary Sciences,
Tohoku University

UESAKA Tomohiro

RIKEN Nishina Center

HIRENZAKI Satoru

Faculty Division of Natural Science, Nara Women's University

NAKANO Takashi

RCNP, Osaka University

SAWADA Shinya

Institute for Particle and Nuclear Studies, KEK

KATO Ryukou

Accelerator Laboratory, KEK

OHGAKI Hideaki

IAE, Kyoto University

SHINOHAR Atsushi

Graduate School of Science, Osaka University

OURA Yasuji

Graduate School of Science and Engineering,Tokyo Metropolitan University* Chairperson- 144 -

ELPH Annual Report, Tohoku University (2019)

Program Advisory Committee
2019
SUDA Toshimi

ELPH, Tohoku University

OHNISHI Hiroaki

ELPH, Tohoku University

KASHIWAGI Shigeru

ELPH, Tohoku University

KIKUNAGA Hidetoshi

ELPH, Tohoku University

NAKAMURA Satoshi*

Graduate School of Science, Tohoku University

SUGIYAMA Kazumasa

Institute for Materials Research, Tohoku University

OZAWA Kyoichiro

Graduate School of Science, KEK2

HOTTA Tomoaki

RCNP, Osaka University

FUJIOKA Hiroyuki

School of Science, Tokyo Institute of Technology

SHOJI Yoshihiko

LASTI, University of Hyogo

GOTO Shin-ichi

Graduate School of Science and Technology,
Niigata University

KUBOTA Takumi

Institute for Integrated Radiation and Nuclear Science,
Kyoto University* Chairperson- 145 -

ELPH Annual Report, Tohoku University (2019)- 146 -

Ⅴ. Approved Experiments

ELPH Annual Report, Tohoku University (2019)2019 年度採択課題
課題番号

課題名

申込責任者

2915

T2K 実験ミューオンモニターのための新型検出器・電⼦増倍市川温⼦

管の電⼦ビームを⽤いた性能評価
2916

LEPS2 ソレノイド実験のためのエアロゲルチェレンコフカウ

時安敦史

ンターの性能評価
2917

グザイハイパー核分光実験 J-PARC E70 に⽤いるアクティ

後神利志

ブシンチレーションファイバ標的の性能試験
2918

ハドロン⽣成実験 EMPHATIC のためのエアロゲルチェレン

⽥端誠

コフ検出器の開発
2920

放射性バナジウム V-48 を⽤いたバナジウム・レドックスフ⽩崎謙次

ロー電池の隔膜の研究 〜加速器による V-48 の製造・第 3 期〜
2921

電⼦ライナック由来 Tc-99m を⽤いたネズミイメージングの上坂充

ための Mo-99 製造
2922

Performance evaluation for a Cherenkov calorimeter with

MA, Yue

PbF2 crystal2923

ハドロン⽣成実験 EMPHATIC に向けた RICH 検出器のため

⽥端誠のマルチレイヤーエアロゲルスキームの最適化
2924

FOREST 超前⽅荷電粒⼦検出で拓く物理

⽯川貴嗣

2925

⾼時間分解能⾶⾏時間差測定装置(resistive plate chamber)⼤⻄宏明特性の⾼抵抗膜電極依存性の研究
2926

4 年⽣学⽣実験：環境に優しいガスを使った Multi-Gap

⼤⻄宏明Resistive plate Chamber の基礎研究
2927

LEPS2 ソレノイド実験のためのエアロジェルチェレンコフカ

時安敦史

ウンターの性能評価Ⅱ
2928

J-PARC E42 実験のための⽔チェレンコフ検出器のビーム試

市川裕⼤

験
2929

FOREST 前⽅ホドスコープ SPIDER の改良

⽯川貴嗣

2930

γd→dX 反応の断⾯積測定

藤岡宏之

2931

JLab における⾼精度ハイパー核分光実験のための⽔チェレン永尾翔

コフ検出器の性能評価- 147 -

ELPH Annual Report, Tohoku University (2019)

2932

MPPC を⽤いたビーム位置検出器の開発と電⼦・陽電⼦ビー

宮部学

ム形状の測定 II
2933

PPD 構造を持つ SOI ピクセルセンサーの電荷収集効率の測

坪⼭透

定
2934

FOREST 超前⽅ π+/K+メソン識別⽤ AC の最終テスト

⽯川貴嗣

2935

時間分解能・位置分解能を実現する新型シリコンセンサーの

末原⼤幹

評価
2936

超低運動量移⾏領域での電⼦散乱による陽⼦の荷電半径測定

本多佑記

2937

Λn Interaction Study via the Final State Interaction

⾦⽥ 雅司

Effect in γd→K+Λn Production2938

家庭ごみ焼却スラグに含まれる希少⾦属元素の回収を⽬指し秋⼭ 和彦

た光量⼦放射化法による成分同定およびトレーサー作成 42939

放射性バナジウム V-48 を⽤いたバナジウム・レドックスフ⽩崎 謙次

ロー電池の隔膜の研究〜加速器による V-48 の製造・第 4 期〜
2940

塩化⽔銀(I)のトレーサスケールにおける揮発挙動研究のた

後藤真⼀

めの無担体 203Hg の製造
2941

Ra-226(γ,n)反応の反応収率測定- 148 -

菊永英寿

ELPH Annual Report 2019
(April 2019-March 2020) March 2021
ONLINE ISSN 2435-9165

Published by
Research Center for Electron-Photon Science (ELPH), Tohoku University
1-2-1 Mikamine, Taihaku, Sendai, Miyagi 982-0826, Japan
Phone:+81-22-743-3411
FAX:+81-22-743-3402
Email:
koho@lns.tohoku.ac.jp
Homepage: https://www.lns.tohoku.ac.jp/
Copyright © 2021 ELPH
All rights reserved

2021 年（令和 3 年）3 月 31 日 発行

国立大学法人東北大学電子光理学研究センターセンター長 濱 広幸
〒982-0826 宮城県仙台市太白区三神峯 1－2－1
電話：
022-743-3411
FAX：
022-743-3402
Email：
koho@lns.tohoku.ac.jp
ホームページ：https://www.lns.tohoku.ac.jp/
発行者