[Neutron] J-PARC Newsletter No. 78
shibata.kaoru
shibata.kaoru at jaea.go.jp
Fri May 29 03:03:01 CEST 2020
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J-PARC Project Newsletter
No.78, April 2020 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]
FIGHT AGAINST COVID-19 AT J-PARC.
2. [Accelerator Division]
OPERATION STATUS OF THE ACCELERATORS.
ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING.
3. [Particle and Nuclear Physics Division]
UPGRADE PLANS OF HADRON EXPERIMENTAL FACILITY.
DATA ACCUMULATION FOR T2K EXPERIMENT WITH UNPRECEDENTED
BEAM POWER AND START OF THE HYPER-KAMIOKANDE PROJECT.
STATUS OF THE MUON G-2/ELECTRIC DIPOLE MOMENT (EDM) (E34).
STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET).
PROGRAMS OF ADVISORY COMMITTEE MEETINGS.
STATUS OF USER OPERATION.
4. [Materials and Life Science Division]
STABLE USER PROGRAM OPERATION HAD BEEN CONTINUED AT 500 kW.
144 GENERAL USERS' AND 1 NEW USER PROMOTION NEUTRON PROPOSALS HAVE BEEN
APPROVED FOR THE 2020A PERIOD.
MUSE ACTIVITIES FORESHORTENED BY THE EPIDEMIC.
5. [Nuclear Transmutation Division]
TEF TECHNICAL ADVISORY COMMITTEE MEETING WAS HELD.
6. [Safety Division]
THE EMERGENCY DRILL CONDUCTED AT MLF.
7TH SYMPOSIUM ON SAFETY IN ACCELERATOR FACILITIES.
7. [Editorial Note]
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1. [Overview] by Naohito SAITO
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FIGHT AGAINST COVID-19 AT J-PARC
We are facing an extraordinary crisis of human life with the new
coronavirus which is still spreading all over the world. We hope you and
your loved ones are in good health. In many countries, non-essential
activities have been postponed and people are asked to stay home or even
more severe regulations are enforced. In Japan, a national state of
emergency was announced in April with initially seven prefectures, mostly
around Tokyo under special alert, then it was extended to cover the entire
Japan to avoid an over-shoot of positive cases. Consequently, we have
decided to pause the operation of J-PARC facility as of April 20, especially
to contribute to subsiding the spread by staying home, hence, a reduction of
contact chances.
The state of emergency is still in effect in those seven prefectures
plus Hokkaido. However, the government clearly stated that this month is the
preparation month towards a "new normal"
life, therefore, we have decided to resume the facility operation.
Many of our users still have difficulties to travel even domestically
due to the travel restrictions by their institutes and their local
governments. The Material and Life Science Facility (MLF) has started from
mail-in service, and experiments by in-house members as of May 15th with 520
kW. Now the MLF is running at 600 kW for user operation for the first time!
The Hadron Experimental Facility (HEF) will start commissioning by
J-PARC staff and users already in Tokai, but will gradually allow incoming
users with counter measures against infections. The HEF operation will enter
its new phase(!) with an operation of new primary beamline, B-Line, which
was finally approved by the Nuclear Regulation Authority as of April 28.
While the challenges remain, we think it is important to resume the
research activities not only to maintain the research itself as an
irreducible part of human civilization, but also to learn about an operation
of a research facility like ours in the similar situations possibly coming
back again in the near future. Of course, it is extremely important to
protect society against further spread of infections and secure staff and
users from risks of infections.
Therefore, we will reinforce the counter measures based on the best possible
knowledge obtained to date. At the same time, the scientific research
activity is undoubtedly important not only for an immediate benefit, but
also for the incubation of novel ideas and fostering the next generations
with scientific competence. Along this line, we are open for any research
interests directly or indirectly related to
COVID-19 at our facility.
While we were forced to stay home and keep distance from others in the
last few months, I think everybody recognizes how important to cooperate
with each other, share ideas, and even disagree sometimes.
Therefore, keep in touch, and stay connected towards the society with
resilience, which can be accelerated by the research facilities like J-PARC.
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2. [Accelerator Division] by Kazuo HASEGAWA
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OPERATION STATUS OF THE ACCELERATORS
After the New Year's holiday, the beam operation started on January 9
as a new operation run of Run#84. The user program resumed for the Materials
and Life Science experimental facility (MLF) on January 14. The beam power
was 500 kW, which was the same as the previous Run#83 by December. The user
program was rather smooth for the MLF by the end of March in the Japanese
Fiscal Year 2019.
For the Main Ring synchrotron (MR), we started the user program for the
Neutrino Experimental Facility (NU). Thanks to the fine tuning of beam loss
mitigation, beam power was well beyond 500 kW. We expected to change from
the NU to beam tuning for the Hadron Experimental Facility (HD) in the
middle of February, but the licensing for a new target and a new beam line
in the HD was delayed from the Authority and beam operation was postponed.
The availability in the Japanese Fiscal Year 2019 (from April
2019 to March 2020) was high: about 95 percent for the MLF since we had no
serious troubles at the linear accelerator (LINAC), the RCS and the MLF. The
availability for the NU and HD facility users was 90% and 80%, respectively.
The cause of the lower availability for the HD was the bending magnet
failure in the beam transport line.
ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING
The 19th A-TAC meeting was held at the J-PARC Research Building on
February 24 to 26. There were nine committee members, of which three
attended remotely due to the COVID-19 or a schedule conflict.
Sixteen reports were presented, such as operational status, commissioning
results, preparation of spares, safety system and performance upgrade. The
committee deliberated the improvements, directivity, etc., and gave comments
and recommendations.
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3. [Particle and Nuclear Physics Division] by T. TAKAHASHI and K. OZAWA
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UPGRADE PLANS OF HADRON EXPERIMENTAL FACILITY (by T. TAKAHASHI and K.
OZAWA)
Upgrade plans of Hadron Experimental Facility are under discussion. We
are planning to extend our Experimental Hall and construct new beam lines to
enhance our physics capabilities. At one of the planned beam lines, we are
aiming to have 10 times better resolution in spectroscopies of Strange quark
nuclei to investigate the nature of a neutron star precisely. In addition, a
beam line will be constructed to study hadron physics using charm quarks.
Also, sensitivities of Kaon rare decays will be improved using a newly
constructed neutral Kaon beam line. Details of the plan are described in the
white paper (arXiv:1706.07916, arXiv:1906.02357). The proposal for the
extension of the Hall, together with g-2, COMET-II projects, has been
selected as one of the 31 important big projects in the Master Plan 2020 of
the Science Council of Japan.
Recently, our colleagues summarized the status of hadron and nuclear
physics at J-PARC in a review paper. The paper has been published in
Progress in Particle and Nuclear Physics (https://
doi.org/10.1016/j.ppnp.2020.103773, arXiv:1912.02380). In this paper, recent
results of the conducted experiments, the purposes and expected results of
on-going and the near-future experiments, and future plans of the extension
of the Hall are reviewed.
DATA ACCUMULATION FOR T2K EXPERIMENT WITH UNPRECEDENTED BEAM POWER AND
START OF THE HYPER-KAMIOKANDE PROJECT (by T. ISHIDA)
Since last November, the T2K experiment (E11) has continued data
acquisition with far detector Super-Kamiokande, which was refurbished in
fall 2019 for scheduled Gadolinium loading. At B2 floor of the near detector
hall, new near detector system, WAGASCI and BabyMIND (E69), has been
successfully commissioned and data taking started.
Another experiment observing neutrino-nucleus interactions by nuclear
emulsion, NINJA (E71), was also running. In the early 2020, the proton beam
intensity reached to 515 kW, and stable data taking was realized with this
unprecedented beam power.
The budget for Hyper-Kamiokande project has been officially approved by
the Japanese diet. The project consists of construction of a gigantic water
Cherenkov detector at Kamioka site, mainly managed by The University of
Tokyo, and upgrade of J-PARC accelerators, neutrino beam line, and near
detector facilities, mainly managed by KEK/J-PARC. Hyper-Kamiokande project
will search for CP violation in the lepton sector with drastically reduced
statistical and systematic errors.
Recent publications:
o Measurement of the muon neutrino charged-current cross sections
on water, hydrocarbon and iron, and their ratios, with the T2K
on-axis detectors.
K. Abe et al.
https://dx.doi.org/10.1093/ptep/ptz070
o Measurement of neutrino and antineutrino neutral-current
quasielasticlike interactions on oxygen by detecting nuclear
deexcitation gamma rays.
K. Abe et al. (T2K Collaboration)
https://dx.doi.org/10.1103/PhysRevD.100.112009
o Hyper-Kamiokande project website:
http://www.hyper-k.org/en/index.html
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 surface muon beamline (H-line) is under construction by the IMSS muon
group.
Strategies for implementing the building extension from the MLF have
been established by a J-PARC taskforce for H-line extension building in
January, 2020.
Demonstration of laser ionization of muonium for the thermal energy
positive muon source is in preparation. A test experiment to ionize hydrogen
atoms is being carried out in KEK Tsukuba campus.
Preparations for 1 MeV acceleration of muon with RFQ and IH-DTL are in
progress at J-PARC linac bldg. A paper on measurement of the longitudinal
bunch distribution after acceleration by an RFQ for negative muonium ions
was published in Phys. Rev. Accel. Beams in collaboration with Nagoya
University.
The three-dimensional beam injection has been studied with low-energy
electron beam by KEK and Ibaraki University. A kicker system for beam
storage was developed.
The silicon tracking detector is being assembled at KEK mechanical
engineering center in collaboration with Kyushu University. A paper on the
silicon-strip detector module was accepted for publication in JINST.
A small steering magnet system in the storage magnet volume is being
designed by KEK and Ibaraki University.
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 sensitivity better than 10^{-14} in
Phase I.
Winding of CS1 coil has been completed successfully in March 2020. This
is the last coil component of the capture solenoid which efficiently
captures and transports pions decaying to muons with a gradient magnetic
field.
Detector preparation is in progress in a stable manner. The CDC, the
main detector for physics measurement in Phase I, is tested using cosmic
muons with full electronics. Mass production of LYSO crystals is ongoing.
Every delivered crystal is carefully inspected one by one in the lab. The
1st station of the straw-tube tracker is ready for final assembly work to
install readout electronics. Detector construction work continues in 2020
and detector conditioning will start at the COMET experiment area once they
are ready.
The collaboration had a collaboration meeting at IIT-Bombay in India in
February; participants from the local area and all over the world came
together to understand preparation status and to discuss future plan of the
experiment.
On March 13th the Technical Design Report of the COMET Phase I has
finally become available online.
https://doi.org/10.1093/ptep/ptz125
PROGRAMS OF ADVISORY COMMITTEE MEETINGS. (by T. KOMATSUBARA)
The 29th Program Advisory Committee (PAC) meeting was held at Tokai on
January 16-18. Status of the experiments was reported, and proposals and
near-term machine time allocation were discussed.
https://kds.kek.jp/indico/event/33442/
PAC report will be available through the following web page.
http://j-parc.jp/researcher/Hadron/en/PAC_for_NuclPart_e.html
The next PAC meeting will be held on July 20(Mon)-22(Wed), 2020.
STATUS OF USER OPERATION (by T. KOBAYASHI, T. KOMATSUBARA)
The fast-extraction of Main Ring for the Neutrino Experimental Facility
was conducted from November 5, 2019 to February 12, 2020.
The slow-extraction for the Hadron Experimental Facility has not started yet
because the procedures for authorization by Nuclear Regulation Authority of
Japan and by local governments have been delayed.
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4. [Materials and Life Science Division] by Toshiji KANAYA
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STABLE USER PROGRAM OPERATION HAD BEEN CONTINUED AT 500 kW
1) Neutron Source
The beam operation of MLF is going very well with a good availability
of 92.7% since December 12 in 2019, as of March 18 in 2020. Due to the
change of the operation mode at the Main Ring synchrotron (MR) accelerator
from the fast extraction mode to the slow extraction mode on February 12,
the proton beam power delivery to MLF increased from 500 kW to 530 kW.
The new mercury target vessel was delivered on March 19. In order to
improve the capability of pitting damage mitigation by increasing the bubble
population near the beam window of the target vessel, the bubble generator
was mounted at the place 100 mm nearer to the beam window than the present
one. This new target vessel is going to be used from this autumn.
144 GENERAL USERS' AND 1 NEW USER PROMOTION NEUTRON PROPOSALS HAVE BEEN
APPROVED FOR THE 2020A PERIOD
2) Neutron Instruments and Science
From January 14 in 2020, we resumed the later part of the user program
for the 2019B period. The 2020A user program will start from April 1 in
2020.
Proposals for 2020A were reviewed by the joint meeting between Neutron
Science Proposal Review Committee (NSPRC) and Proposal Evaluation Committee
(PEC) held on February 5 in 2020 and 144 general users' proposals for
neutron instruments and 1 new user promotion proposal for public beamlines
were approved. This result was authorized by the joint meeting between MLF
Advisory Board and Selection Committee on February 19 in 2020.
The Neutron Advisory Committee meeting (NAC) was held on February 17-18
in 2020. The following highly evaluated comments were received that MLF has
an excellent suite of instruments that provide the capability to produce
correspondingly excellent science. The official recommendations documents
are in preparation.
The epidemic of COVID-19 has been affecting our activities.
Quantum Beam Science Festa and MLF symposium, which were scheduled to be
held on March 12-14 in 2020 were cancelled together with related satellite
user meetings. Regarding the user program, it is being in a situation that
many experimental user groups cannot but cancel their travels to J-PARC due
to the COVID-19 problem so that such experiments are listed in to the
reserved subjects which will be carried out later if there will be vacancy
in the beam time. This rule may depend on how situation of this disease
changes.
MUSE ACTIVITIES FORSHORTENED BY THE EPIDEMIC
3) Muon Science Facility (MUSE)
When the members of the Muon Science Proposal Review Committee gathered
on January 28 in 2020 for reviewing 2020A muon proposals, no one would have
imagined the forthcoming impact of the coronavirus epidemic that broke out
in China. The review panel accepted 41 general-use proposals including three
P-type and one S2-type, and approved 25 proposals through D1/2 and S1
instruments while 13 proposals got reserved status due to the limited
availability of beam time, put on the waiting queue according to their
priorities.
In the meantime, the epidemic kept soaring, spreading to Japan and
other countries through February while the annual international advisory
committees over every levels of J-PARC activities were about to be taking
place. It was fortunate that those for Division/Section levels including
Muon Advisory Committee Meeting (MAC) were held just in time before the
situation reached an alarming level.
The user program of MUSE has been also foreshortened by the growing
concern about the epidemic, as some experimenters from abroad were forced to
cancel their visit to Japan. In contrast, its influence for facility
operation, as of now, has been minimal.
The new muon production target has been serving normally since last
November with 500 kW proton beam, and users at D1/2 and S1 instruments are
busy running experiments using high-flux muon beams.
The high-flux beam makes it comfortable for those who are working on the
commissioning of the "ultra slow muon" at U1A/B areas.
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5. [Nuclear Transmutation Division] by Toshinobu SASA
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TEF TECHNICAL ADVISORY COMMITTEE MEETING WAS HELD
The sixth TEF Technical Advisory Committee (T-TAC) meeting was held in
J-PARC site during February 6-7 in 2020. Three Japanese members and three
foreign members from Belgium and Germany gathered to review the current
progress of the TEF facility plan and related research and development work.
In the first day, J-PARC staff introduced an outline of the experimental
facility plan and individual activities to establish elemental technologies
for facility components, such as Lead-Bismuth Eutectic alloy (LBE) target
remote handling and elemental technologies for LBE instrumentation.
JAEA also proposed the importance of proton and neutron irradiation in
actual LBE flow condition. 10 presentations including the future R&D plan
were reviewed by the TAC members. In the second day, TAC members observed
the Neutrino Experimental Facility and experimental setups for LBE
technology development (large experimental loops, Remote handling test
device and LBE instrumentation). After the closed discussion on the second
day by the TAC members, many recommendations and comments to advance the R&D
activities were indicated at the end of the meeting. T-TAC suggested that
the R&D plan was feasible, provided that particular attention was given to
the alignment between the deliverables to be provided by the target
technology developments and the needs of the design works for the
experimental facility.
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6. [Safety Division] by Kotaro BESSHO and Yoshihiro NAKANE
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THE EMERGENCY DRILL CONDUCTED AT MLF
The emergency drill was conducted on January 9, 2020 at the Material
and Life science experimental Facility (MLF). The drill assumed a scenario
where radioactive material was abnormally released from the facility during
MLF operation. The drill scenario started when facility managers and key
personnel were notified by a staff member who noticed abnormal instrumental
readout in the operation/control room. It was confirmed that there was a
helium gas leak from the mercury target vessel. The drill progressed through
steps such as collaboration between the accident-site command post and
on-site response headquarters, checking the status of the accidental site,
ensuring the safety of human lives, and holding a simulated press release.
7TH SYMPOSIUM ON SAFETY IN ACCELERATOR FACILITIES
The 7th Symposium on Safety in Accelerator Facilities was held on
January 23-24 at Ibaraki Quantum Beam Research Center (IQBRC) with
125 participants. The featured topics were "Interlocks at Accelerator
Facilities" and "Ensuring Safety in Machine Work". There was also a talk on
the fire which occurred in April 2019 at the KEK Tsukuba Campus. Nine talks
and fourteen posters were presented, and active discussions were conducted.
At the end, it was announced that the International Technical Safety Forum
2020 will be held in November
2020 at the Riken Wako Campus.
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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 Taketoshi 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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