J-PARC Project Newsletter No.84, October 2021 dispatch
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J-PARC Project Newsletter
No.84, October 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]
“SUWA PRIZE” AWARDED TO THE ACCELERATOR DIVISION FOR THEIR
ACHIEVEMENT ON 1 MW BEAM ACCELERATION AT 3 GeV RCS.
SPECIAL EXHIBITION AT THE NATIONAL MUSEUM OF NATURE AND SCIENCE
SUCCESSFULLY CLOSED WITH 78272 VISITORS.
FIRST J-PARC USERS COUNCIL MEETING UNDER THE NEW MANAGEMENT HELD
ON JULY 13th.
2. [Accelerator Division]
OPERATION STATUS OF THE ACCELERATORS.
3. [Particle and Nuclear Physics Division]
PROGRAM ADVISORY COMMITTEE MEETING.
HADRON HALL EXTENSION PLAN.
ON GOING UPGRADE WORK TOWARDS HIGHER BEAM POWER AND PRECISE
NEUTRINO MEASUREMENT.
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 OPERATION ENDED SUCCESSFULLY AND MAINTENANCE WORKS ARE
GOING ON.
PROPOSALS FOR 2021B ROUND WERE REVIEWED.
CONSTRUCTION AND MAINTENANCE WORKS IN PROGRESS.
5. [Nuclear Transmutation Division]
IMPURITY EVAPORATION BEHAVIOR OF ALKALI ELEMENTS FROM
LEAD-BISMUTH EUTECTIC.
6. [Safety Division]
8TH SYMPOSIUM ON SAFETY IN ACCELERATOR FACILITIES.
7. [Editorial Note]
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1. [Overview] by Takashi KOBAYASHI
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“SUWA PRIZE” AWARDED TO THE ACCELERATOR DIVISION FOR THEIR
ACHIEVEMENT ON 1 MW BEAM ACCELERATION AT 3 GeV RCS
With pleasure we would like to report that the J-PARC accelerator
division was awarded the honorable “Suwa Prize” in memory of
Dr. Shigeki Suwa, the first director of KEK, for their achievement
on 1 MW beam acceleration at 3 GeV RCS. All the scientific outcomes
from J-PARC are relying on the continuous efforts by the accelerator team
on improving the performance of the J-PARC accelerator complex. We,
together with users, congratulate and thank the accelerator team.
https://j-parc.jp/c/topics/2021/06/04000699.html (only in Japanese)
http://www.heas.jp/award/jusyo.html (only in Japanese)
SPECIAL EXHIBITION AT THE NATIONAL MUSEUM OF NATURE AND SCIENCE
SUCCESSFULLY CLOSED WITH 78272 VISITORS
A Special Exhibition on Accelerator, at the National Museum of Nature
and Science in Ueno, Tokyo, was held during July 13 to Oct 3rd and
78,272 visitors visited it. J-PARC was deeply involved in the preparation;
exhibitions from J-PARC include the mercury target vessel of MLF and
the graphite target for Neutrino Facility. On July 24th, a special
lecture by Prof. Hitoshi Murayama (UC Berkeley/Kavli IPMU) was
given with COVID protection in place.
https://www.kahaku.go.jp/event/2021/07accelerator/ (only in Japanese)
FIRST J-PARC USERS COUNCIL MEETING UNDER THE NEW MANAGEMENT HELD
ON JULY 13th
On July 13th, the J-PARC Users Council was held online. Committee
members consist of representatives from relevant user communities of
J-PARC. Prof. Toshio Yamaguchi (Fukuoka University) was elected
mutually as the new chair of the council. This time, the council was
asked to summarize the needs/requests from user communities, and
will summarize the requests in a document to the J-PARC director.
https://kds.kek.jp/event/38692/ (only in Japanese)
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2. [Accelerator Division] by Michikazu KINSHO
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OPERATION STATUS OF THE ACCELERATORS
The beam operation for the MLF users was completed on July 15 as
scheduled with high availability (~ 97%).
The beam operation as an operation run of Run#87, which started in
May, has been continued until July 20th on schedule. The beam operation
for the MLF users was completed on July 15 as scheduled with high
availability (~ 97%). The beam power for the Materials and Life Science
experimental facility (MLF) user program was reduced from 740 kW to
630 kW from June 24 due to insufficient cooling capacity of the cooling
water system of the RCS in summer. After the user operation, beam
studies were carried out for 5 days at the linac and at the RCS to
reduce beam loss and further increase intensity.
After the beam study, the summer maintenance work started at the
linac and the RCS and is still in progress.
The linac had been operated stably in these several months. But
one of the Separated-type Drift Tube Linac (SDTL) cavities had
a symptom of increasing radio frequency reflection power in the
vicinity of the designed operation power. The reason was a dirty
surface of the cavity. So it was cleaned with dilute hydrochloric
acid dipped cloths.
The 3 GeV Rapid Cycling Synchrotron (RCS) also had been operated
stably before summer. However, beam power had to be reduced from
740 kW to 630 kW due to insufficient cooling capacity of the cooling
water system for high power operation of the RCS in summer. It was
found that this insufficient cooling capacity was due to the reduction
of the heat exchange efficiency of the heat exchanger in the cooling
water system. Since this reduction in heat exchange efficiency was
due to contamination, we have been performed cleanup this heat
exchanger.
The Main Ring (MR) has entered a long maintenance period for
upgrade from July 1st until next autumn . The work has been
progressing smoothly in preparation for the beam study operation
in June next year.
The J-PARC accelerator facilities are scheduled to start beam
tuning at the linac on November 15. After the tuning, beam studies
of the accelerators (linac and RCS) are planned till the end of this
year; the user operation of the MLF is expected to start in the middle
of January next year.
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3. [Particle and Nuclear Physics Division] by Toshiyuki TAKAHASHI and Kyoichiro OZAWA
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PROGRAM ADVISORY COMMITTEE MEETING (by Takeshi KOMATSUBARA)
The 32nd Program Advisory Committee (PAC) meeting was held as a
video conference on July 14-16. In the committee, chaired by Dr. Rik
Yoshida (Argonne National Laboratory), status of the experiments were
reported and prospects for the operation after the long shutdown of
Main Ring were discussed.
This time seven new proposals, including the ones for the
extended Hadron Experimental Facility, were submitted.
https://kds.kek.jp/indico/event/38719/
The 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 in January 2022.
HADRON HALL EXTENSION PLAN (Toshiyuki TAKAHASHI, Tadashi NOMURA,
Kyoichiro OZAWA)
Near future upgrade plans of the Hadron Experimental Facility are
under discussion. The current plan contains a new production target
and four new beamlines, such as new K1.1 beamline,
High-Intensity-High-Resolution (HIHR) beamline, K10 beamline, and new
KL beamline. Further studies in strangeness nuclear physics will be
performed at the K1.1 and HIHR beamlines. Experimental information of
hyper-nucleus and hyperon-nucleon interactions are crucial to
understand the QCD equation of state for dense hadronic matter.
Experiments for spectroscopic studies of multi-strange baryons
will be performed at the K10 beamline using a high-momentum K- beam.
The experiments aim to have new experimental information for light
(u, d, s) diquarks and their role in strange baryons.
The KOTO step-2 (KOTO-2) experiment will be carried out at the new
KL beamline. The KOTO-2 aims to measure the branching ratio of
KL -> pi0 nu nu-bar with ~30 % precision, assuming the Standard Model
decay rate. This branching ratio is one of the most important
measurements to explore the physics beyond the Standard Model.
Three new proposals, which are related with the upgrade plan, were
submitted to the last PAC meeting and a dedicated review was held on
August 10, 11, and 17, 2021. The review committee made several positive
comments on the plan.
ON GOING UPGRADE WORK TOWARDS HIGHER BEAM POWER AND PRECISE
NEUTRINO MEASUREMENT (by Yoshiaki FUJII)
The neutrino experimental facility and T2K experiment group are
working very hard on improvement of apparatuses toward beam restart
expected around the end of 2022.
The neutrino experimental facility is working on the beam-power
upgrade project aiming at achieving 1.3MW by 2027, when HyperK
is planned to start data taking, without disturbing T2K beam running.
Not only the secondary beamline but also the primary beamline,
which is basically beam-loss driven, needs careful optimization for
the high-power beam. Especially at the most-downstream part of the
primary beamline, it suffers intense radiation from the downstream
target and becomes highly radio-active in the Hyper-K era. New
maintenance scheme under such high radiation environment is
being implemented during this maintenance period.
The ND280 upgrade projects are speeding up the construction toward
their on-site work starting from early 2022. The Super-Fine-Grained
Detector group started fabrication of the structural container of the
two-million scintillator cubes, and is reviewing the final assembly work
at J-PARC. The high-angle TPC group plans to start on-site gas system
reconfiguration from early 2022. Procedures to travel to Japan under
COVID situation is extensively being examined.
Dr. Sara Bolognesi (CEA/DAPNIA Saclay), one of the most active
collaborator of T2K, has been awarded
"The Summer 2021 Emmy Noether Distinction of the European Physical Society".
As is described at
https://www.eps.org/blogpost/751263/375831/,
the Summer-2021-EPS-Emmy-Noether-Distinction was awarded to Sara
Bolognesi for her work at CMS.
However it is also a pleasure for the T2K collaborators to salute
a colleague's great honor.
STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET)
(by Satoshi 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 and detector construction work continues; along with beam
line and experiment area construction the COMET detector construction
team is intensively preparing detector components and related
electronics. The main physics detector CDC is conditioned on the KEK
campus by using cosmic rays. The CDC group is finalizing the cooling
system for the readout electronics equipping the detector. A beam
measuring detector composed of a straw-tube tracker and a LYSO
calorimeter is constructed at J-PARC step by step. The 1st station of
the straw-tube tracker is now ready for an initial test and calorimeter
assembly work is starting.
There is another intensive activity in the data analysis of the 8 GeV
acceleration test and beam extinction measurement carried out in May
2021. A preliminary analysis reports that a beam extinction factor
better than 10^{-10} is achieved, which is sufficient to realize the
COMET phase-I sensitivity. Further improvement is expected by
carefully investigating the details of proton leakage mechanism in the
accelerator as well as improving the measurement technique of the beam
extinction factor. This result has already been reported in a summer
conference and at the JPS meeting.
The COMET collaboration members started planning to visit J-PARC
in JFY 2021 in order to make direct contributions to detector integration
for the COMET engineering run Phase-alpha and physics data acquisition
in Phase-I.
STATUS OF THE MUON G-2/ ELECTRIC DIPOLE MOMENT (EDM) (E34)
(by Tsutomu MIBE)
The E34 collaboration prepares for precision measurements of the
muon anomalous magnetic moment and electric dipole moment.
The virtual workshop on the precise calculation of muon anomalous
magnetic moment in the standard model was organized by KEK from
June 28 to July 2nd. There were 283 participants from 27 countries to
discuss improvements of the theory precision in the framework of
the muon g-2 theory initiative which is a worldwide initiative formed
since 2017.
The workshop was organized in memory of Prof. Simon Edelman who
played a central role in this initiative and in the E34 collaboration.
KEK worked on the design of the experimental building as well as
the relocation of the access road and buried facility infrastructure on
the construction site. The collaboration assisted the construction and
commissioning of new experimental area with surface muon, the S2
experimental area, where the demonstration of laser ionization of
muonium is planned.
Development of ionization lasers are in progress at KEK Tsukuba
campus. The design of the extension of the H-line for E34
installation is also in progress.
The area layout and radiation shields have been designed.
The collaboration continues to work on developments of the key
experimental components.
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4. [Materials and Life Science Division] by Toshiya OTOMO
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BEAM OPERATION ENDED SUCCESSFULLY AND MAINTENANCE WORKS
ARE GOING ON
1) Neutron Source
The beam operation of MLF continued stably with 600 kW, which
was brought down from 700 kW on June 24th to secure the cooling
capacity of the accelerator devices, and ended on July 17th. The
daily availability since April 1st was 97.5 % on average.
On July 29th, the used mercury target vessel, which was in
operation from 2014 to 2015, was transported from MLF to the storage
building, which is called RAM building where a total of 4 used target
vessels are stored now.
The cooling tower of the coolant water loop for the devices of
3GeV proton beam transport line (3NBT) was replaced as a
countermeasure against aging deterioration. The cooling capacity was
increased that will contribute to stable beam operation during the summer.
PROPOSALS FOR 2021B ROUND WERE REVIEWED
2) Neutron Instruments and Science
The neutron proposals for the period 2021B starting next
January, were reviewed. The total number of submitted neutron
general proposals was 338. Finally, 137 neutron general proposals
were approved by the MLF Advisory Board on September 1st.
The Annual meeting of industrial application at J-PARC MLF was
held as an online meeting on July 15th and 16th. This meeting can
be a great communication channel between the industrial society
and MLF for sharing information and to discuss for practical use of
neutron technique in the industry. 352 participants including 150
from companies attended. Several talks on facility report, status on
industrial use and its expectation, and advanced scientific case were
presented.
Three recent scientific press releases at MLF were issued as follows:
(1)."Behavior of light elements in iron-silicate-water-sulfur system
during early Earth’s evolution"
https://doi.org/10.1038/s41598-021-91801-3
(2)."Local Structure of Li+ in Superconcentrated Aqueous LiTFSA
Solutions"
https://doi.org/10.1021/acs.jpcb.1c04693
(3)."Hydrogen storage by earth-abundant metals, synthesis and
characterization of Al3FeH3.9"
https://doi.org/10.1016/j.matdes.2021.109953
CONSTRUCTION AND MAINTENANCE WORKS IN PROGRESS
3) Muon Science Facility (MUSE)
Although the COVID-19 pandemic continues to have a negative
impact on muon experiments under Inter-University Research Program
at MUSE, the scheduled proposals for the 2020B-2021A period were
carried out relatively smoothly thanks to the efforts of the staff,
and were successfully completed on July 15th, 2021.
The highlights of the experiment were the initial analysis of
the samples returned by Hayabusa-2 , using a non-destructive elemental
analysis method with negative muon capture characteristic X-rays,
and the first successful muon beam transport to the S2 Area.
Following the shutdown of accelerator facility, construction
works for the remaining part of H line has resumed in the MLF
building, which will continue throughout the remaining of the year
as the resumption of operation has been postponed till January, 2022.
The installation works for infrastructures such as electricity and
cooling water supplies to beamline magnets are in steady progress
since last summer. The regular maintenance is also in progress for
the rotating target and other beamline components in parallel with
the construction works.
Meanwhile, MUSE received many proposals for the 2021B round
nearly equal to the last call for 2020B-2021A round, making it highly
competitive for users to get beamtime. In response to this situation,
the Muon Science Proposal Review Committee has taken the temporary
measure of limiting the number of proposals approved for one PI to
one, so that as many users as possible can be given the opportunity
to do experiment. Finally, for the 2021B round, the total number of
submitted proposals was 73 for the muon general proposals, of which
32 were approved.
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5. [Nuclear Transmutation Division] by Hayanori TAKEI
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IMPURITY EVAPORATION BEHAVIOR OF ALKALI ELEMENTS FROM
LEAD-BISMUTH EUTECTIC
Lead-Bismuth Eutectic (LBE) is a candidate material as a neutron
generation target and a coolant in an Accelerator Driven System (ADS)
proposed by Japan Atomic Energy Agency (JAEA). In the LBE of ADS,
many radioactive materials are produced as spallation products (SPs)
via spallation reactions between a proton beam and the LBE, which
leads to highly radioactive LBE. It is crucial to evaluate the release
and transport behavior of the SPs from the LBE coolant to the cover
gas from the viewpoints of the radiological hazard both in the cases
of normal operation and accident.
In order to understand the evaporation behavior of Cs and Rb,
which are produced in large amounts among alkaline metal elements
from the LBE, the chemical species and vapor pressures were measured
using a Knudsen effusion mass spectrometer (KEMS). As a result, Cs
and Rb were found to be easily evaporated from LBE. This experimental
result was announced at the 2021 Fall Meeting of the Atomic Energy
Society of Japan on September 8th.
The results of this study were obtained through a contract
research to the University of Fukui.
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6. [Safety Division] by Yoshihiro NAKANE and Kotaro BESSHO
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8TH SYMPOSIUM ON SAFETY IN ACCELERATOR FACILITIES
The 8th Symposium on Safety in Accelerator Facilities was held on
August 27th by online meeting, and 121 participants exchanged
information on safety issues at accelerator facilities.
Six presentations from accelerator facilities were made on recent
situation of each facility and safety activities under the novel
coronavirus pandemic. Circumstances and difficulties concerning
application for a license of the accelerator operation at each facility
were also shared.
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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
Takatoshi MORISHITA: morishita.takatoshi@jaea.go.jp
Jean-Michel POUTISSOU (English Editor): jmp@triumf.ca
Keiko NEMOTO (Secretary): nemoto.keiko@jaea.go.jp
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