[Neutron] J-PARC Newsletter No. 83

Wed Aug 4 10:22:34 CEST 2021

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     J-PARC Project Newsletter
                               No.83, July 2021 Japan Proton Accelerator Research Complex under operation jointly by the High Energy Accelerator Research Organization (KEK) and the Japan Atomic Energy Agency (JAEA) 
http://j-parc.jp/index-e.html 
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HEADLINES AND CONTENTS

1. [Overview]

   NEW MANAGEMENT STARTED FROM APRIL 1st, 2021.

2. [Accelerator Division]

   OPERATION STATUS OF THE ACCELERATORS.

3. [Particle and Nuclear Physics Division]

   CURRENT AND FUTURE OF THE HADRON EXPERIMENTAL FACILITY.
   UPGRADE WORK OF THE NEUTRINO EXPERIMENT FACILITY TOWARD 1.3 MW BEAM POWER HAS STARTED.
   STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET).
   STATUS OF THE MUON G-2/ ELECTRIC DIPOLE MOMENT (EDM) (E34).

4. [Materials and Life Science Division]

   BEAM POWER WAS RAISED TO OVER 700 kW.
   PROPOSALS FOR 2021B ROUND WERE RECEIVED.
   MUSE GOT OFF TO A GOOD START IN FY2021.

5. [Nuclear Transmutation Division]

  TWO WORKSHOPS ON J-PARC’S IRRADIATION FACILITY WERE HELD BY THE NUCLEAR TRANSMUTATION DIVISION.

6. [Safety Division]

  THE PERIODICAL INSPECTION WAS SUCCESSFULLY CONDUCTED BY THE RADIATION MANAGEMENT INSTITUTE, INC.(RAMI).
  J-PARC SAFETY DAY 2021.
  THE APPLICATION FOR A LICENSE OF THE OPERATION WAS GRANTED.

7. [Editorial Note]

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1. [Overview] by Takashi KOBAYASHI
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  NEW MANAGEMENT STARTED FROM APRIL 1st, 2021

     New management took over the successful former management headed by Dr. Naohito Saito, who had served the J-PARC director for 6 years since April 2015. We would like to thank Saito-san and former management for their great contribution to J-PARC.
     I, Takashi Kobayashi, took over the J-PARC director from this April for 3 years. I have been working on accelerator-based long baseline neutrino oscillation experiments.
     We have three deputy directors; all of them are new.
     Dr. Yukihiro Miyamoto is the deputy director in charge of Safety,
     Dr. Shuichi Wakimoto and Dr. Fujio Naito are in charge of JAEA and KEK, respectively.
     The organization structure, Division Heads and Section leaders can be found at https://j-parc.jp/c/en/about/organization.html
     We, all the J-PARC members, will work together with all of the users to maximize the scientific outcome from J-PARC with the safety at highest priority.

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2. [Accelerator Division] by Michikazu KINSHO
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  OPERATION STATUS OF THE ACCELERATORS

     Achieved a new record for continuous operation of ion source and bunched slow beam extraction at energy of 8 GeV successfully conducted at MR

     The beam operation as an operation run of Run#86, which started late in November last year, continued until April 30th on schedule.
The beam power for the Materials and Life Science experimental facility (MLF) user program increased from 600 kW to 700 kW on April 5th. The neutrino user operation was carried out from April 8th to end of this operation run of Run#86 at the beam power of 510 kW after HD user operation.
     A new operation run of Run#87 was started in May after ion source replacement. The reason why the ion source was replaced was not because it was broken, but to prevent it from being broken during the user operation.
     The continuous operation record of this replaced ion source was more than 3600 hours (3651 hours), which is more than 1.5 times longer than the previous continuous operation time and a new record.
     The user program resumed for the MLF on May 10th. The beam power for the MLF user was 700 kW which was the same as the previous user operation by April. The MLF user program will be performed until July 15th before summer shutdown.
     The user program resumed for the hadron on May 11th. The maximum beam power of 64 kW was achieved through repeated adjustments, and the utilization operation was carried out at this power. The hadron user program will be performed until end of June.
     From May 19 to 25, the Main Ring synchrotron (MR) suspended the normal hadron user operation, and carried out a test run for the COMET experiment. In this test operation, we worked on bunched slow beam extraction at energy of 8 GeV instead of the usual continuous slow beam extraction at energy of 30 GeV. In this test operation, good experimental data were obtained for the realization of the COMET experiment.
     The MR will enter a long maintenance period until next autumn for upgrade from July 1st. 

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3. [Particle and Nuclear Physics Division] by T. TAKAHASHI and K. OZAWA
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  CURRENT AND FUTURE OF THE HADRON EXPERIMENTAL FACILITY (by T. Takahashi and K. Ozawa)

     The slow-extraction of Main Ring for the Hadron Experimental Facility was conducted from March 27 to April 7, 2021 and from May 10 to June 29, 2021. In the first operation period, we completed the data acquisition for measurements of X-rays from Xi- atoms at the K1.8 beam line. The X-rays measurements aim to study Baryon-Baryon interactions at Strangeness S=-2 sector. In the second operation period, an H-dibaryon search experiment completed their data taking.
The H-dibaryon is a particle which contains two sets of up, down, and strange quarks. Whether the H-dibaryon exists or not is a long-standing issue in hadron physics.
     The KOTO experiment continued their data acquisition to search for K_L to pi0 nu nu-bar decays at the KL beam line in both operation periods. Also, an experiment at the B line to study mass modifications of vector mesons in a nucleus took pilot data for evaluations of detector performances. At K1.8BR beamline, pilot data on lifetime measurements of hypertriton were taken and extinction measurements were also carried out for a mu-e conversion experiment (COMET).
     In addition to the current experimental activities, future plans of the Hadron Experimental Facility were intensively discussed. We have a plan to extend the current experimental hall and construct additional beam lines, such as K1.1 beam line, High-Intensity-High-Resolution (HIHR) beamline, K10 beamline, and new KL beamline. We have following workshops to discuss physics opportunities and designs of beam lines.
  Workshop on Physics at the J-PARC K10 beam line (5/13-14):
  https://indico.rcnp.osaka-u.ac.jp/event/1672/
  Workshop on Physics at HIHR and K1.1 beam lines (5/23):
  https://kds.kek.jp/event/38112/
  Workshop on Physics of Omega Baryons at the J-PARC K10 beam line (6/7-9):
  https://indico.rcnp.osaka-u.ac.jp/event/1689/
  Strangeness in Neutron Stars --Physics at J-PARC HIHR/K1.1 beam lines (6/17-19):
  https://kds.kek.jp/event/38476/
  International Workshop on the Extension Project for the J-PARC Hadron Experimental Facility (7/7-9): 
  https://indico2.riken.jp/event/3773/

  UPGRADE WORK OF THE NEUTRINO EXPERIMENT FACILITY TOWARD 1.3 MW BEAM POWER HAS STARTED（by Y. Fujii)

     The second half of the T2K run in 2021 resumed on 4/8 and ended on 4/27. Stable operation with 510kW beam power was achieved through this run, and nearly planned POT was accumulated. Integrated POT from the start of the experiment has reached 2.17x10^21 for neutrino mode and 1.65x10^21 for anti-neutrino mode. NINJA also finished pilot data taking successfully with heavy-water target and a new time-stamp movers, and are developing their emulsion plate.
     After this run, the neutrino experiment facility has entered long shutdown period for regular maintenance, improvement and replacement of equipment necessary for coming 1.3MW operation. Excitation test of the new horn strip lines, feed-throughs, and the transformer was successfully carried out with 320kW operation current. The new horns with all these components will be installed during this shut down period to welcome the new run in fall 2022.
     Dr. Chris J. Densham at Rutherford Appleton Laboratory, an innovator of T2K and many other neutrino production targets, has won the 2021 Institute of Physics Prize for Outstanding Professional Contributions to accelerator science and technology.
http://www.j-parc.jp/c/en/topics/2021/06/03000696.html

  STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET) (by S. MIHARA)

     The COMET experiment aims to search for the lepton-flavor violating muon reaction, mu-e conversion, with a sensitivity better than 10^{-14} in Phase I.
     Facility construction work continues; along with beam line and experiment area construction the COMET cryogenics group is intensively preparing a liquid helium refrigerator and peripheral equipment such as a current lead box (CLB). The CLB delivers electric current to the superconducting magnet coils with temperature transition from the room temperature to the liquid helium temperature with GM-refrigerators equipped on the top of the box. The initial cooling test was carried out in June successfully.
     The COMET collaboration has finally completed  an 8-GeV acceleration and beam extraction test to measure the beam extinction factor in the Hadron hall in May. In this test an improved proton injection method from RCS to MR was tested and optimized, resulting in successfully removing remaining protons in the 1st 100 msec during the beam extraction period observed in the previous test in 2018.
Detailed data analysis is in progress to be reported in the coming J-PARC PAC meeting.
     The COMET collaboration plans to have the 34th collaboration meeting early July to discuss the progress and status toward the start of an engineering run (Phase alpha) in JFY 2022 and the physics run (Phase I) in JFY 2023. The meeting will be held fully online also this time with participation from 7 different time zones.

  STATUS OF THE MUON G-2/ ELECTRIC DIPOLE MOMENT (EDM) (E34) (by T. MIBE) 

     The E34 collaboration prepares for precision measurements of the muon anomalous magnetic moment and electric dipole moment.
     The collaboration had the 22nd collaboration meeting from June 1 to 4 to discuss the progress of the experimental preparation. The collaboration also organized invited lectures on the Fermilab g-2 experiment by Dr. Peter Winter (ANL) and Dr. On Kim (KAIST), and g-2 BSM theory by Dr. Teppei Kitahara.
     KEK is preparing for a funding request of base facilities, building and utilities. The collaboration worked with the facility group to optimize design of the experimental building as well as the relocation of the access road and buried facility infrastructure on the construction site.
     The collaboration is working on construction of the experimental equipment. Demonstration of laser ionization of muonium for the thermal energy positive muon source is in preparation at MLF S2 area.
The fabrications of the prototypes for  IH-DTL cavity and DAW cavity are ongoing. A pulsed electron beam is being prepared for the demonstration of the 3D spiral injection.
     The final version of the frontend electronics was successfully produced.

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4. [Materials and Life Science Division] by Toshiya OTOMO
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  BEAM POWER WAS RAISED TO OVER 700 kW

1) Neutron Source
     The beam operation of MLF is going on very well with the daily availability of 97.4 % on average since April 1st, as of June 16th in 2021. The beam power was raised from 600 kW to over 700 kW on April 5th. Actually, MLF is receiving 740 kW during the MR operation period with slow extraction mode, which is the highest power ever attained for long term user operation of MLF. The power will be decreased to 600 kW from June 24th in order to increase the cooling capacity margin of accelerator devices under the humid and hot weather of summer. After the user program will end on July 15th, 1MW beam operation with the duration time of 16 hours is going to be held from July 16th to 17th.

  PROPOSALS FOR 2021B ROUND WERE RECEIVED

2) Neutron Instruments and Science
     The MLF 2021B call for general use proposals (short-term and one-year) was closed on May 14th, we have 325 neutron proposals including 9 new user promotion proposals. The experimental periods are from November 2021 to March 2022 for short-term proposal (tentative) and from November 2021 to July 2022 for one-year proposal (tentative) respectively. The portion of the proposals from foreign countries increases from 31% for 2020B+2021A to 37% for 2021B. All the proposals are now under review process whose results will be notified till the end of September 2021.
     For discussing the future aspects of MLF, the consortium of instruments in-house workshops “MLF2030-Neutron” was launched.
     Three groups of instruments such as spectroscopy instruments, elastic scattering instruments, and fundamental physics and others beamlines now get started their discussions about instrumental concepts, R&D for revolutionary devices, management of scientific / user programs, and so on. By the end of this fiscal year, the fundamental principles of MLF will be summarized.
     The18th Korea-Japan meeting on neutron science hosted by JSNS (The Japanese Society for Neutron Science), J-PARC MLF and KNBUA (The Korean Neutron Beam Users Association) has been held on April 30th as an online meeting. After the facility reports from J-PARC MLF in the morning session, Korean users of J-PARC, HANARO and the other neutron facilities present six topics in the research fields of polymer and softmatter sciences, material engineering, magnetism and neutron instrumentation in the afternoon session, followed by parallel discussions in three breakout rooms whose topics was selected by the requests from Korean (potential) users of J-PARC. The number of the participants was 77 (48 participants from Korean and 29 participants from Japan).
     The recent notable publications at MLF neutron science were as follows,
  1) “Colossal Barocaloric Effect by Large Latent Heat Produced by First-Order Intersite-Charge-Transfer Transition”
      https://doi.org/10.1002/adfm.202009476
  2) “Suppressed Lattice Disorder for Large Emission Enhancement and Structural Robustness in Hybrid Lead Iodide Perovskite Discovered by High-Pressure Isotope Effect”
      https://doi.org/10.1002/adfm.202009131
  3) “Stabilization of Size-Controlled BaTiO3 Nanocubes via Precise Solvothermal Crystal Growth and Their Anomalous Surface Compositional Reconstruction”
      https://doi.org/10.1021/acsomega.0c05878
  4) ”Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms”
      https://doi.org/10.1107/S1600576721000303
  5) ”Chemical-Pressure-Induced Point Defects Enable Low Thermal Conductivity for Mg2Sn and Mg2Si Single Crystals” 
      https://doi.org/10.1021/acsaem.1c00670
  6) “Anion ordering enables fast H‒ conduction at low temperatures”
      https://doi.org/10.1126/sciadv.abf7883

  MUSE GOT OFF TO A GOOD START IN FY2021

3) Muon Science Facility (MUSE)
     In response to the recent remarks by the Muon Advisory Committee (MAC) and the International Advisory Committee (IAC) of J-PARC, the Muon Section will receive a budget for the production of a new muon target from the new fiscal year. The project will be carried out over a period of two years, with the target storage container to be fabricated in the first year and the rotating target body in the second year. This is because it is necessary to reexamine the applicability of the Hot Isostatic Pressing (HIP) technique in advance, which is the key to target fabrication. Regarding another issue of the persistent manpower shortage raised by the MAC, a new recruitment of assistant professor (female quota) was approved by KEK in March, and the final approval was given at the IMSS Management Committee held in May for the hiring of the candidate selected by the Personnel Committee. The new appointment will be effective on August 1st.
     With regard to Inter-University Research Programs, MUSE has made a beam schedule to minimize the impact of COVID-19 by concentrating the implementation of overseas user proposals in the latter half of 2021A period (till mid-July). However, the current situation still does not allow us to see prospects of oversea users finding way to Japan.
Although the MLF has been discussing the possibility of remote experiment since the end of last year, there are many issues to be considered prior to institutionalizing and operating it immediately.
The impact of COVID-19 was felt by the radiation regulatory administration, and the review of facility modifications including those for MUSE by the Nuclear Regulation Authority (NRA) was prolonged for many months. However, the permission from the NRA has recently been obtained, and after prior approvals from JAEA and the surrounding municipalities, it is expected that the modification work will be possible shortly. Now we may have a chance of getting the first beam out to the S2 area within the 2021A period.
     Meanwhile, in this proposal round, MUSE received 73 muon proposals for the 2021B periods, and the review process for these proposals is now underway.

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5. [Nuclear Transmutation Division] by Hayanori TAKEI
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  TWO WORKSHOPS ON J-PARC’S IRRADIATION FACILITY WERE HELD BY THE NUCLEAR TRANSMUTATION DIVISION

     The workshop entitled “Possibilities of Material Irradiation Facility with High Power Accelerator” was held on March 30th, 2021 using the meeting tool “Zoom”, and 80 researchers participated in it.
The J-PARC’s irradiation facility plan, needs for the irradiation data, and the current status of domestic and foreign irradiation facilities were reported. It was also discussed that there are many young researchers who have little experience in irradiation tests due to the lack of irradiation facilities, and therefore the needs for irradiation facilities are extremely high.
     Another workshop entitled “Development of the semiconductor soft error research at J-PARC” was held on March 31st, 2021 using the Zoom, and 66 researchers participated in it. The current status of the soft error research by cosmic rays and the irradiation plan for the soft error at J-PARC were reported. The necessity of irradiation tests not only for the device itself but also for the entire system, the importance of industry-academia collaboration, and increasing the awareness of soft errors were also discussed.

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6. [Safety Division] by Yoshihiro NAKANE and Kotaro BESSHO
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  THE PERIODICAL INSPECTION WAS SUCCESSFULLY CONDUCTED BY THE RADIATION MANAGEMENT INSTITUTE, INC. (RAMI)

     The periodical inspection was successfully conducted and the certificate was issued on March 30th by RAMI. The periodic inspection is taken once every five years to make sure that radiation installations are maintained in compliance with technical standards by the Radiation Regulation Law.

  J-PARC SAFETY DAY 2021

     The J-PARC Center had held "the J-PARC Safety Day" around May 23rd on which the radioactive material leak incident occurred in 2013.
The Safety Day in FY2021 was held on May 28th by online meeting.
Some good-practices were awarded by the director, and work management at the RCS facility was introduced. Following these programs, the main talk entitled "Assertion culture supporting safety at the engineering and maintenance department, ANA" was given by Mr. Satoru Nabeshima, ALL NIPPON AIRWAYS CO., LTD. Further an updated video documentation on the radioactive material leak incident in 2013 was presented.

  THE APPLICATION FOR A LICENSE OF THE OPERATION WAS GRANTED

     The application for changes of the radiological license was granted by the Nuclear Regulation Authority (NRA) on June 9. The approved changes in the application were a new and a modified muon beamlines in the Materials and Life Science Experimental Facility and an expansion of the drainage equipment in the Neutrino Experimental Facility.

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7. [Editorial Note]
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Past issues are available from the below link.
http://j-parc.jp/c/en/topics/project-newsletter/index.html

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Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto at kek.jp 
Kaoru SHIBATA: shibata.kaoru@ jaea.go.jp 
Takatoshi MORISHITA: morishita.takatoshi at jaea.go.jp
Dick MISCHKE (English Editor): mischke at triumf.ca 
Keiko NEMOTO (Secretary): nemoto.keiko at jaea.go.jp
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