[Neutron] J-PARC Project Newsletter No.90, April 2023

[會澤恭子]

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　 J-PARC Project Newsletter
　　                       No.90, April 2023
Japan Proton Accelerator Research Complex under joint operation
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]

THE INTERNATIONAL ADVISORY COMMITTEE MEETING WAS HELD ON FEBRUARY
24TH AND 25TH IN PERSON AFTER FOUR YEARS OF NO FACE-TO-FACE MEETING.

2. [Accelerator Division]

BEAM COMMISSIONING OF THE MR STARTED ON JANUARY 23RD, THE BEAM WAS
SUPPLIED STABLY AT A BEAM ENERGY OF 8 GEV FOR THE RADIATION FACILITY
INSPECTION OF THE HADRON EXPERIMENTAL FACILITY ON MARCH 14TH.

ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING WAS HELD.

3. [Particle and Nuclear Physics Division]

PROGRAM ADVISORY COMMITTEE MEETING.

MORE POWERFUL BEAM IS COMING.

STATUS OF THE JSNS2 / JSNS2-II (SEARCHING FOR STERILE NEUTRINOS AT
J-PARC MLF, E56 / E82).

NEW PRIMARY BEAM LINE FOR THE COMET EXPERIMENT.

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]

MLF USER OPERATION SCHEDULE FOR THE 2023A PERIOD.

STABLE USER PROGRAM OPERATION HAD CONTINUED AT 730 KW AND 810 KW.

PROPOSALS FOR 2023A ROUND WERE APPROVED.

THE EXTENSION PLAN OF THE H LINE CONSTRUCTION IN THE H2 AREA WAS
APPROVED BY THE NUCLEAR REGULATION AUTHORITY.

5. [Nuclear Transmutation Division]

THE TECHNICAL ADVISORY COMMITTEE (T-TAC) MEETING WAS HELD.

6. [Safety Division]

THE SAFETY INSPECTION WAS SUCCESSFULLY CONDUCTED.

7. [Information]

8. [Editorial Note]


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1. [Overview] by Takashi KOBAYASHI
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THE INTERNATIONAL ADVISORY COMMITTEE MEETING WAS HELD ON FEBRUARY
24TH AND 25TH IN PERSON AFTER FOUR YEARS OF NO FACE-TO-FACE MEETING
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The Annual International Advisory committee (IAC) of J-PARC met on
February 24th and 25th in person after four years of no face-to-face
meeting. The IAC is a committee to advise the J-PARC center’s
director and the directors general of JAEA and KEK on all aspects of
J-PARC’s operation ranging from safety, science output, to the
management and organization. The committee consists of 16
distinguished researchers from around the world and chaired by
Dr. Robert McGREEVY from STFC.
http://j-parc.jp/c/en/forum-and-committee/iac-e.html
We could have deep and dense discussions with face-to-face meeting
and received many important and valuable pieces of advice which will
be our "guiding light" to maximize the performance of J-PARC. That
reconfirmed the importance of the in-person meetings.


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2. [Accelerator Division] by Michikazu KINSHO
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BEAM COMMISSIONING OF THE MR STARTED ON JANUARY 23RD, THE BEAM WAS
SUPPLIED STABLY AT A BEAM ENERGY OF 8 GEV FOR THE RADIATION FACILITY
INSPECTION OF THE HADRON EXPERIMENTAL FACILITY ON MARCH 14TH
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OPERATION STATUS OF THE ACCELERATORS
After the New Year's holiday, the beam operation resumed on January
7th as part of Run#90, which started in November, and the user
program resumed for the Materials and Life Science Experimental
Facility (MLF) on January 12th. The beam power was about 730 kW
which was the same as for the previous user operation before
shutdown. The beam power was changed between 730kW and 810kW due to
the change of the MR repetition cycle. The user program was rather
smooth for the MLF by March 15th on schedule.
The beam power and the availability for the MLF in the Japanese
Fiscal Year 2022 (from April 2022 to March 2023) were 730kW-830kW
with more than 95 percent availability, respectively, because we had
no serious troubles at the linear accelerator (linac), the 3 GeV
synchrotron (RCS) and the MLF.
Beam commissioning of the Main Ring (MR) was postponed till January
23rd, 2023 from the originally scheduled 19th November due to the
delay of tunning of the new power supply and the failure of the beam
extraction magnet. The MR operation from January to March has been a
combination of slow extraction adjustment for the COMET experiment
operation at beam energy of 8 GeV and fast extraction adjustment with
30 GeV acceleration pattern at the energy of 8 GeV. The beam was
supplied stably at beam energy of 8 GeV for the radiation facility
inspection at the Hadron Experimental Facility on March 14th, and the beam
operation was finished on morning of March 15th on schedule.

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ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING WAS HELD
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The 22nd A-TAC meeting was held from January 26th to 28th and for the
first time in three years, the meeting was held in a hybrid format,
with the meeting mainly held on-site. Six of the nine committee
members attended the meeting on-site and three attended remotely.
The main topics of discussion at this meeting were the status of the
accelerator, the progress of the MR expansion plan, and responses to
the previous recommendations. The committee considered the
improvements, the prospects, etc., and gave recommendations.


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3. [Particle and Nuclear Physics Division]
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PROGRAM ADVISORY COMMITTEE MEETING (by Takeshi KOMATSUBARA)
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The 35th Program Advisory Committee (PAC) meeting was held as a
hybrid conference on January 23-25 2023. At the meeting, chaired
by Dr. Rik Yoshida (Argonne National Laboratory), the status of the
experiments was reported and prospects for the operation from
February onwards were discussed.
This time three proposals, including two new ones, requested Stage-1
status and three experiments requested Stage-2 approval.
https://kds.kek.jp/event/45134/
The PAC report will be available through the following web page.
https://j-parc.jp/researcher/Hadron/en/PAC_for_NuclPart_e.html
The next PAC meeting will be held in July 2023.

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MORE POWERFUL BEAM IS COMING (by Yoshiaki FUJII)
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T2K group is eagerly waiting for the beam, re-scheduled to start up
mid-April.
The beam group finished a two-year-long maintenance and upgrade work,
and confirmed beam readiness on March 1st. Cooling of the cryogenic
system is scheduled to start from April 3rd, and a so-called dry-run
will be executed on April 13th.
Since quite a huge number of beamline devices have been replaced by
new, more powerful ones, beam commissioning of the first beam in two
years will be done with great care, step by step, as was done for the
first beam in 2009.
At ND280, assembly work of the SFGD (Super Fine-Grained Detector) is
in progress at J-PARC. Stacking of its two million cubes had been
completed last December, and installation of 56,000 fibers was
completed in February. Installation of optical sensors and
electronics is in progress. The gas system of the High-Angle TPCs
will be delivered in April. The first shipping of the high-angle TPC
module itself to the J-PARC will be done in June. The new ToF
counters will be shipped to J-PARC also in June. The upgrade work of
ND280 is accelerating.
Hyper-K will have a PAC meeting from 4/11 to 4/13 at Tokai in a
long-awaited in-person style, and then will have a collaboration
meeting from 6/26 to 7/1 also at Tokai in-person.

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STATUS OF THE JSNS2 / JSNS2-II (SEARCHIING FOR STERILE NEUTRINOS AT
J-PARC MLF, E56 / E82) (by Takasumi MARUYAMA)
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The JSNS2 (E56) / JSNS2-II (E82) collaboration searches for neutrino
oscillation over a short distance with sterile neutrinos at J-PARC
MLF.
For JSNS2, a new long physics run started in April-2023 after the
existing near detector reinstallation on the 3rd floor of MLF. During
the run, the new electronics are being commissioned in addition to
the normal data taking. For JSNS2-II, the new far detector is under
construction. Eighty-one 10-inch PMTs out of 228 in total were
installed in the far detector by end of Feb-2023. The acrylic tank
of the far detector was successfully produced at a Taiwanese company,
and was delivered to J-PARC at the end of Mar-2023. JSNS2-II aims to
start its data taking within FY2023.

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NEW PRIMARY BEAM LINE FOR THE COMET EXPERIMENT (by Hitoshi TAKAHASHI)
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The Hadron Experimental Facility (HEF) has had two primary proton
beamlines, "A-line" and "B-line". The 30-GeV protons are slowly
extracted from the Main Ring and transported to the Hadron Hall
through the A-line. They are directed to the production target to
produce secondary beams such as pions and Kaons, which are then
delivered to user experiments.
A portion of the primary protons is separated off from the A-line to
the B-line before the production target. The proton beams at the
B-line are provided directly for user experiments.
The operation of the HEF started with the A-line in 2009, and the
B-line started in 2020.
The construction of the third primary proton beamline, "C-line", was
completed. The C-line is a beamline that branches off from the middle
of the B-line, and provides an 8-GeV proton beam for the COMET
experiment. The first beam commissioning of the C-line was carried out on
February 9, 2023. The change of our license as an RI facility was
finally approved on March 15 after the official facility inspection
on March 14.

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STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET)
(by Satoshi MIHARA)
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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.
Prior to acquiring the physics data in Phase I, the COMET group
prepared Phase α as an engineering run to measure the behavior of
the proton beam and its secondary particles. Phase alpha beam time
was allocated in February and March 2023 for five days for
accelerator commissioning and for eight days for beam measurements.
The proton beam was injected into a thin graphite target and its
property was measured with beamline apparatus. The radiation level
around the beamline, and properties of secondary particles such as
pions, muons, and electrons transported to the experiment area by
the transport solenoid were measured. The COMET group succeeded in
identifying muons in the beam with its momentum distribution
evaluated by the range counter data.
Further data analysis is in progress to understand the muon beam
produced in the COMET facility.

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STATUS OF THE MUON g-2/ ELECTRIC DIPOLE MOMENT (EDM) (E34)
(by Tsutomu MIBE)
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The E34 collaboration aims for precision measurements of the muon
anomalous magnetic moment and electric dipole moment.
The collaboration set up an experiment to demonstrate muon cooling
by means of the resonant laser ionization of muonium atoms at MLF S2
area. This experiment successfully took data until the middle of
March. More data will be taken after April, followed by the
first-ever demonstration of the RF acceleration of thermal-energy
muons with RFQ before summer.
The radiation shielding blocks and walls were assembled to define
the new experimental area (the H2 area) to host the muon cooling and
initial acceleration part of the muon g-2/EDM experiment.
The preparation for extension beyond the MLF building is in progress
to relocate the drainage water piping in the area. The plan for the
building is now in a final stage of refinements.


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4. [Materials and Life Science Division] by Toshiya OTOMO
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MLF USER OPERATION SCHEDULE FOR THE 2023A PERIOD
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The MLF User Operation in the 2023A period has been scheduled for
60 days from April 16th to June 21st. The schedule for the 2023B
period will be announced later.
https://mlfinfo.jp/en/announce/230210.html

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STABLE USER PROGRAM OPERATION HAD BEEN CONTINUED AT 730 KW AND 810 KW
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1) Neutron Source
Beam operation of MLF had continued very well with the excellent
availability of more than 95% and ended on March 15th as scheduled.
After the user program resumed on November 21st, 2022, beam power
at MLF was changed several times between 730 kW and 810 kW according
to the change of beam extraction cycle at the 30 GeV main ring (MR)
for beam study. During the short outage from March 15th to April
15th, maintenance works of the off-gas process system and the primary
water coolant system are going to be held.
There were two international collaboration workshops on-site at
J-PARC. One was held from February 27th to March 1st with ISIS of
Rutherford Appleton Laboratory. Information exchange in the field
of the accelerator system and neutron/muon target system was the
primary scope. Another workshop was held from March 22nd to 24th
with the Spallation Neutron Source (SNS) of Oak Ridge National
Laboratory to discuss the neutron source system issues. Many
fruitful discussions were held in both workshops.

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PROPOSALS FOR 2023A ROUND WERE APPROVED
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2) Neutron Instruments and Science
The new proposal round 2023A is for the period from April to June
2023. Two hundred seventy-seven proposals have been submitted for
neutron general use proposals (short-term and one-year) and new user
promotion proposals. All submitted proposals were reviewed by Neutron
Science Proposal Review Committee (NSPRC) / Expert Panel of Proposal
Evaluation Committee (PEC) followed by MLF Advisory Board, and 122
proposals were approved and 123 proposals were reserved.
The international neutron advisory committee meeting (NAC-2023) has
been held in-person style + online style on February 9th and 10th
under the chair of Dr. Jamie Schulz (Australian Nuclear Science and
Technology Organization (ANSTO)). It was the first time in three
years that the meeting was held in-person style. It reviewed the
current status of MLF and its latest research results and industrial
applications using neutron beams, and provided an assessment from the
NAC committee that the neutron source operation plan and ongoing
technological development were appropriate.
Quantum Beam Science Fiesta FY2022 (QBSF2022), which is a yearly
event for domestic users of MLF and IMSS (Institute of Materials
Structure Science in KEK) was held in hybrid- style from March 13th
to 15th, together with the 14th MLF symposium and the 40th PF
symposium. QBSF2022 ended up with great success, with 414
participants on-site and 475 participants online.
A recent scientific press release at MLF from neutron instruments
was issued:
"Neutron crystallography and quantum chemical analysis of bilin
reductase PcyA mutants reveal substrate and catalytic residue
protonation states"
https://doi.org/10.1016/j.jbc.2022.102763


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THE EXTENSION PLAN OF THE H LINE CONSTRUCTING THE H2 AREA WAS
APPROVED BY THE NUCLEAR REGULATION AUTHORITY
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3) Muon Science Facility (MUSE)
The U1A area in the U line has resumed operation back from the
trouble in the longitudinal-field magnet that happened in the middle
of November after the safety review. The magnet and its power
supplier were renewed by taking preventive measures in the interlock
system.
The extension plan of the H line, constructing the H2 area, was
approved by the Nuclear Regulation Authority, and the construction
is going to be done during a break between March and April. The
apparatus for the H2 area has been prepared and is ready to be
assembled. The muon accelerator will be constructed in the extension
of the H line by passing through the existing MLF wall to the
extension building, and the first stage of the accelerator is placed
in the H2 area at this time. The civil works in advance of the
extension building construction like the cable relocation have been
in progress around the MLF building.
In the Muon Science Proposal Review Committee (MSPRC) meeting, 43
proposals submitted for the 2023A period were reviewed, with 23
approved, 13 reserved, and the remainder (including two performed
or to be performed in the 2022B period) not approved.
The Muon Advisory Committee (MAC) meeting was held from February 20th
to 21st under the chair of Prof. Thomas Prokscha, Paul Scherrer
Institute (PSI). This was the first in-person style meeting since
2020. Deeper communications resulted from such an in-person style.
The progress in each beamline/instrument was presented by its
respective manager, some of whom have taken over in this fiscal year
as part of a generational transition. Activities such as the
development of the ultra-slow muon beam and negative muon usage were
considered. Prioritizing various projects and drawing up a long-term
prospect were recommended to the MUSE management.


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5. [Nuclear Transmutation Division] by Hayanori TAKEI
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THE TECHNICAL ADVISORY COMMITTEE (T-TAC) MEETING WAS HELD
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The ninth TEF (Transmutation Experimental Facility) Technical
Advisory Committee (T-TAC) meeting was held via online meeting on
February 3rd, 2023. Three Japanese and four foreign committee members
from Belgium, Germany, and Switzerland gathered to review the current
progress of the TEF facility plan and related research and
development work. J-PARC staff members introduced their activities
to realize the experimental facility, such as the technologies for
lead-bismuth eutectic alloy target and instrumentation, neutronics,
and accelerator technologies in the meeting.
On February 21st, 2023, we received the final T-TAC report in which
observations, comments, and recommendations were provided. T-TAC
suggested that "the R&D works carried out by J-PARC as highly
valuable contributions to the international Accelerator-driven
transmutation system (ADS) community and acknowledged the continuous
efforts deployed by J-PARC to set-up collaborations with other
organizations on national and international level in the frame of
the Japanese ADS program". T-TAC gave us positive comments on the
establishment of the user community for the TEF facility and
recommended internationalizing such a user community.


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6. [Safety Division] by Yoshihiro NAKANE and Kotaro BESSHO
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THE SAFETY INSPECTION WAS SUCCESSFULLY CONDUCTED
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The safety inspection of the Hadron Experimental Facility was
successfully conducted, and the certificate of compliance was issued
on Mar.15 by Radiation Management Institute, inc. The inspection
items were the shielding construction prepared for a new primary
beamline (COMET), and the measurement of radiation dose rate around
the shielding construction in the Hadron Experimental Facility.


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7. [Information]
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8. [Editorial Note]
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Past issues are available from the link below.
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 at jaea.go.jp
┃ Takatoshi MORISHITA: morishita.takatoshi at jaea.go.jp
┃ Jean-Michel POUTISSOU (English Editor): jmp at triumf.ca
┃ Chiaki SHIRAISHI (Secretary): shiraishi.chiaki at jaea.go.jp
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