J-PARC Project Newsletter No.78, April 2020 dispatch
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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@kek.jp
Kaoru SHIBATA: shibata.kaoru@ jaea.go.jp
Taketoshi MORISHITA: morishita.takatoshi@jaea.go.jp
Dick MISCHKE (English Editor): mischke@triumf.ca
Keiko NEMOTO (Secretary): nemoto.keiko@jaea.go.jp
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