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J-PARC Project Newsletter
No.59, July 2015
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]
TOWARDS A NEW PHASE OF J-PARC OPERATION.
2. [Accelerator Division]
STEADY PERFORMANCE IMPROVEMENT AND BEAM DELIVERY OF ACCELERATORS.
3. [Particle and Nuclear Physics Division]
A K-PP BOUND STATE SEARCH VIA THE IN-FLIGHT KAON REACTION ON
HELIUM-3.
T2K RELEASED ITS FIRST MEASUREMENT OF MUON-ANTINEUTIRNO
DISAPPEARANCE.
COMET FACILITY CONSTRUCTION STEPPED FORWARD; G-2/EDM TDR SUBMITTED TO
J-PARC PROGRAM ADVISORY COMMITTEE (PAC).
4. [Materials and Life Science Division]
GREETING FROM THE NEW LEADER OF THE MATERIALS AND LIFE SCIENCE
EXPERIMENTAL FACILITY (MLF) DIVISION.
AN INVESTIGATION OF THE TARGET VESSEL TROUBLE IS IN PROGRESS.
CALL FOR PROPOSALS FOR 2015B PERIOD WAS CANCELLED.
J-PARC HOSTED NEUWAVE7 AND THE 2ND IAC OF RADEN.
MUON BEAMLINE OPERATION RESUMED.
5. [Nuclear Transmutation Division]
LEAD-BISMUTH SPALLATION TARGET MOCKUP LOOP FOR TRANSMUTATION
EXPERIMENTAL FACILITY STARTS OPERATION SUCCESSFULLY.
6. [Safety Division]
THE SAFETY INSPECTION IN HADRON EXPERIMENTAL FACILITY (HD).
7. [Editorial Note]
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1. [Overview] by Naohito SAITO
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TOWARDS A NEW PHASE OF J-PARC OPERATION
J-PARC is a research facility engaged in cutting-edge research in
a variety of fields. This research is carried out using world-class
high-intensity proton accelerators built through a joint effort by the
High Energy Accelerator Research Organization (KEK) and the Japan
Atomic Energy Agency (JAEA). In a wide range of research fields
-including materials and life sciences, elementary particles and
nuclear physics- we aim to contribute broadly to humankind by
promoting diverse research and developments covering from basic
science to industrial applications. We achieve this goal by offering
new means of research, employing beams of neutrons, muons, neutrinos,
K-mesons and various other secondary particles, to our many users not
only from Japan but also from overseas.
Since J-PARC began operations in 2008, we have steadily increased
beam intensities, worked hard to enhance the capability of facilities,
and achieved a variety of results appropriately reflecting the nature
as a multi-purpose research facility. Typical examples of research
include: elucidation of the neutrino oscillation phenomenon and
investigation of the strong interaction in the area of elementary
particle and nuclear physics research; and discovery of new
superconductivity phenomena, elucidation of function in biological
materials, and development of new materials in the area of materials
and life sciences research. I hope to further develop these lines of
research, and contribute to the solution of mysteries surrounding the
origin of the cosmos, matter and life.
In the year before last, there was a radioactive material leak
incident at the Hadron Experimental Facility, and as a result, we
caused a tremendous amount of worry and trouble to many people. We
have reflected deeply on this, and recognize more strongly than ever
that our research can only take place with the support of the public.
To ensure that the same mistakes are not repeated, we have worked hard
to rebuild and strengthen our safety management system, and have
reformed our organization to ensure even greater safety at J-PARC. We
will continue to make unflagging efforts as a research facility with a
total commitment to safety.
I feel my mission will be to develop J-PARC, this international
research center built up by my great predecessors, into a research
facility which can contribute further to the progress of humankind as
an organization based in Japan in Asia. I plan to achieve this by
promoting collaboration with research institutions inside and outside
Japan, increasing use by industry, promoting interdisciplinary
research which makes the most of J-PARC's unique characteristics as a
multi-purpose facility, and broadly sharing the obtained research
results with the public.
Let me take a few moments to introduce new management members:
Dr. Tetsuro ISHII, deputy director for safety
Dr. Masatoshi FUTAKAWA, deputy director
Prof. Tadashi KOSEKI, deputy director
In addition, we warmly welcome new MLF division leader, Prof. Toshiji
KANAYA. We will work closely to fulfill the mission mentioned above.
As we move forward, I would like to ask for your understanding,
guidance and encouragement.
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2. [Accelerator Division] by Kazuo HASEGAWA
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STEADY PERFORMANCE IMPROVEMENT AND BEAM DELIVERY OF ACCELERATORS
A new Japanese Fiscal Year of 2015 started on April 1 and the
beam operation, RUN#62 was started. An accelerator study work was
carried at the beginning of the operation and beam loss reduction
parameters were studied when the painting area expanded in the Rapid
Cycling Synchrotron (RCS).
On April 8, beam delivery to users of the Materials and Life Science
Experimental Facility (MLF) was resumed at 400 kW as before in the FY
2014. We increased beam power to 500 kW on April 14. Since we
confirmed that there was no serious increase of residual dose rates,
we had stably operated at 500 kW after that. That was a new record of
the power for the user operation at the MLF. Most unfortunately,
however, the operation to the MLF was suspended due to a defect of a
neutron production target on April 30.
In the main ring synchrotron (MR), performance confirmation was
started by beam transport to the hadron experimental facility on April
9. The inspection of the nuclear safety authority was conducted on the
17th. The user operation was started on the 24th at the beam power of
24 kW, which was the same level with the incident in May 2013. The
beam power was carefully increased to 27 kW. We had delivered beam
stably and the user operation was ended as scheduled on the morning of
May 7.
We had switched to the fast extraction mode for the neutrino facility.
The beam power was 290 kW in the beginning, and it was improved to
330 - 345 kW thanks to parameter tuning. We stably delivered beams at
the power level of 330 kW to the neutrino users until June 3.
We changed the fast extraction mode to the slow extraction mode for
the hadron facility users. The beam power started from 26 kW and it
was improved gradually to 33 kW. The user operation ended in the
evening of June 26 without long beam trips in this RUN.
At the end of the RUN, accelerators study for higher beam
current was performed until in the morning of July 1. Peak current
from the linac was increased to 40 mA from 30 mA, which was nominal
level at user operations. We had performed studies of the linac, beam
loss reduction in the RCS, and parameter survey for higher power
operation in the MR. We have entered a summer maintenance period after
that.
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3. [Particle and Nuclear Physics Division] by T. HASHIMOTO,
T. TSUKAMOTO AND S. MIHARA
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A K-PP BOUND STATE SEARCH VIA THE IN-FLIGHT KAON REACTION ON HELIUM-3
(by T. HASHIMOTO)
In-medium properties of hadrons under high-density condition are
important keys to deepen the understanding of quantum chromodynamics
(QCD). In the strangeness sector, kaonic nuclear states are predicted
as a consequence of the strongly attractive KbarN interaction, and it
is a good probe to investigate QCD properties in an extreme condition.
In E15, we have searched for the simplest kaonic nuclear state,
"K-pp" via the in-flight K- reaction on 3He at 1 GeV/c.
The "K-pp" could be efficiently produced in this reaction since low-
momentum-transfer (200-300 MeV/c) quasi-elastic scattering is possible
at the forward angle.
We recently published the results of the semi-inclusive missing-
mass analysis of 3He(K-,n)X at zero degrees using the data-set
obtained with 4-day beam in 2013 (Run#49c). [PTEP 2015, 061D01:
http://dx.doi.org/10.1093/ptep/ptv076]
No significant peak structure was observed in the deeply bound region
corresponding to the K-pp binding energy larger than 80 MeV, and upper
limits of a few hundred micro barn/sr were obtained.
On the other hand, we found significant excess of the yield in the
sub-threshold region, which cannot be explained by any elementary-
reaction processes. Further analysis is ongoing to understand the
sub-threshold structure with the help of new data-sets of H2 and D2
targets obtained in 2015.
T2K RELEASED ITS FIRST MEASUREMENT OF MUON-ANTINEUTIRNO DISAPPEARANCE
(by T. TSUKAMOTO)
T2K started antineutrino beam operation by reversing horn current
from May 2014 and accumulated about 4x10^20 POT (protons on target)
with antineutrino beam operation by June 3 (the last day of neutrino
beam line operation before summer) and 350-kW proton beam power is
achieved.
T2K released its first measurement of muon-antineutrino
disappearance in a seminar at the KEK High Energy Accelerator Research
Organization on 18th May, 2015
(https://www2.kek.jp/physics-seminar/files2015/20150518_T2K.pdf ).
This result has been obtained from data taken from May 2014 - March
2015 when T2K has been running mostly with antineutrino beam
operation. 59.8 events would have been expected in T2K's far detector
Super-Kamiokande if there were no antineutrino oscillations. However
only 17 events were observed, which matches the expected
"disappearance" due to muon antineutrinos oscillating into tau
antineutrinos.
Analysis with data accumulated by June 3 is being carried out to
be presented at international conferences in this summer.
COMET FACILITY CONSTRUCTION STEPPED FORWARD; G-2/EDM TDR SUBMITTED TO
J-PARC PROGRAM ADVISORY COMMITTEE (PAC) (by S. MIHARA)
The COMET (E21) experiment searching for the mu-e conversion with
a target sensitivity of 10^{-14} in Phase I has taken a major step
toward the start of the experiment.
Construction of the building for the whole COMET apparatus was
completed in March, 2015. The interior finish work on its upper floor
was also accomplished in May, 2015 where control rooms of COMET and
other experiments and/or the beamline group of the Hadron hall are
integrated. Intensive preparation work of the COMET experiment will
continue in 2015.
The E34 collaboration for precision measurements of muon
anomalous magnetic moment and electric dipole moment submitted a
technical design report written by 136 authors from eight countries to
the program advisory committee in May.
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4. [Materials and Life Science Division] by Toshiji KANAYA
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GREETING FROM THE NEW LEADER OF THE MATERIALS AND LIFE SCIENCE
EXPERIMENTAL FACILITY (MLF) DIVISION
I assumed leadership of the MLF division in J-PARC on June 1,
2015 from Kyoto University. J-PARC/MLF has almost finished the
construction phase, and will come to the final power of 1MW soon.
J-PARC/MLF is really an excellent facility in the hardware: excellent
accelerators, good targets for neutron and muon, and many marvelous
spectrometers. These are the results of great efforts by many J-PARC
and MLF people, especially the former MLF leader, Dr. Masa Arai.
We are now in the operation phase and our next mission is to produce
excellent results in science and industrial applications using the
splendid hardware in MLF. This must be a duty of MLF because we owe
taxpayers for the full use of the excellent facility. I am more than
happy to work with MLF staff and users in the world to produce
excellent outcomes in the near future.
Toshiji Kanaya
Leader of the Materials and Life Science Experimental Facility
Division
AN INVESTIGATION OF THE TARGET VESSEL TROUBLE IS IN PROGRESS
1) Neutron Source
After a trouble happened on the target vessel in April 30, 2015,
we have been investigating the cause of the trouble in detail. We
have found a defect on the shroud of the target vessel, the outermost
layer of the vessel. The target vessel will be replaced with a new one
during the summer shutdown period.
CALL FOR PROPOSALS FOR 2015B PERIOD WAS CANCELLED
J-PARC HOSTED NEUWAVE7 AND THE 2ND IAC OF RADEN
2) Neutron Instruments and Science
User program of 2015A period started on April 19 and was
interrupted by the problem of the target vessel on April 30 as it was
already reported in a special issue of J-PARC Project Newsletter
released previously. The experiments that were affected by this
unexpected beamstop have been carried over. To accommodate these
experiments, we decided to cancel the call for proposals for 2015B
period. Note that urgent proposals can be submitted as usual.
The J-PARC Center and CROSS hosted the seventh workshop on
NEUtron WAVElength-dependent imaging (NEUWAVE7) from May 31 to June
3 at the Ibaraki Prefectural Culture Center in Mito. We had 55
participants from United States, Europe and Japan, and had 29
presentations. After NEUWAVE7, we had the 2nd meeting of the
international advisory committee for our new neutron imaging
instrument, RADEN (Chair: Dr. Eberhard H. Lehmann) on June 4 at
Ibaraki Quantum Beam Research Center in Tokai. Issues including
performance evaluation obtained at commissioning and user program
plan were reviewed.
MUON BEAMLINE OPERATION RESUMED
3) Muon Science Facility (MUSE)
While the Materials and Life Science Facility (MLF) was in
operation since this February, the Muon Section staff had concentrated
into the reinvestigation of beamline components and instruments to
confirm safety for restarting operation of D-, U-, and S-lines after
the fire incident occurred in the MUSE. Following the tightened safety
measures implemented by J-PARC Center, instruments and devices dealing
with high power electricity (such as magnet power supply) were checked
with utmost care. The results of reinvestigation were reviewed by MLF
Safety Panel for each beamline successively, and they were endorsed
for the operations by the end of May. Since the operation of MLF has
been forced to stop again by neutron target vessel trouble, the
resumption of muon beam delivery is scheduled in this autumn.
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5. [Nuclear Transmutation Division] by Toshinobu SASA
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LEAD-BISMUTH SPALLATION TARGET MOCKUP LOOP FOR TRANSMUTATION
EXPERIMENTAL FACILITY STARTS OPERATION SUCCESSFULLY
Nuclear Transmutation Division advances the research and
development for application of lead-bismuth eutectic (LBE) alloy to
establish the LBE spallation target for J-PARC ADS Target Test
Facility (TEF-T). A mock-up LBE loop for TEF-T primary loop system
was built in fiscal year 2014, which has a capacity to set the
temperature gradient of 100 degree between a hot-leg and a cold-leg
by a 60kW electric heater and a secondary water-cooling circuit. LBE
will circulate in the loop by an electro-magnetic pump, which has same
specifications for the TEF-T primary loop. Other components needed to
build TEF-T, such as an ultrasonic flow meter, a prototype spallation
target head, continuous type inductive LBE level meters were also
installed in the loop. More than 250 litter of LBE has been filled
into the loop.
From the end of March 2015, we have performed the functional
test of the loop components including the calibration of the
measurement equipment at lower temperature range around 200 degree
centigrade in saturated oxygen concentration in LBE. The circulation
of LBE with rated flow amount, 120 liter/minute, was established in
an isothermal operation condition at 200 degree centigrade.
For the next step of the functional tests, operation in higher
temperature range above 400 degree centigrade with small temperature
gradient will be performed. The upgrade of the mockup loop is underway
to add the function to manage the oxygen concentration in LBE, which
is important to suppress the corrosion of structural materials by LBE
and accumulation of oxide slugs in LBE, and prototypes of control and
monitor systems for future TEF-T.
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6. [Safety Division] by Yukihiro MIYAMOTO and Kotaro BESSHO
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THE SAFETY INSPECTION IN HADRON EXPERIMENTAL FACILITY (HD)
The safety inspection of Hadron Experimental Facility was
successfully conducted, and the certificate was issued on April 20 by
the Nuclear Safety Technology Center (NUSTEC).
The inspection items are as follows:
1) Shielding structures of the beam line
2) Measurements of ambient doses around the shielding and radiation
controlled area boundary
3) Air tightness of beamline tunnel
FY2015 WORKSHOP FOR FOSTERING SAFETY CULTURE AT J-PARC
The Workshop for Fostering Safety Culture at J-PARC is held every
year around May 23, the date when the radioactive material leak
incident occurred at the Hadron Experimental Facility in 2013.
This year, the workshop was held on May 22 at the auditorium of
the Nuclear Science Research Institute (JAEA-Tokai) in order to
improve safety awareness for J-PARC staff members and not to forget
the lessons learned from the incident. In the workshop, the invited
talk entitled "Psychology on risk communication and crisis
communication" was given by Shoji Tsuchida, Professor of Faculty of
Safety Science, Kansai University. There were also talks by Naohito
Saito, Director of the J-PARC Center, and by Tetsuro Ishii, Deputy
Director of J-PARC Center.
THE PERIODICAL INSPECTION WAS STARTED BY NUSTEC
The periodical inspection that is conducted once every five years
was started by the NUSTEC from May 25, to make sure that the radiation
installations such as the linear accelerator facility and the 3-GeV
synchrotron are maintained in compliance with technical standards by
the Radiation Hazards Prevention Law. It will be held until this
October.
On the site, the confirmation of the installation situation of
the legal signs, exhaust equipment, drainage equipment, activation
products storage facilities (the latter three are new items with the
revision of the law), and the operation tests on the safety interlocks
and the measurement of radiation dose rates (except LI, RCS, MLF) were
done. In addition to the site inspection, the records concerning to
radiation management such as operating logs, exposure records, and
records of education and training of radiation workers, etc., were
also inspected.
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7. [Editorial Note]
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Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto@kek.jp
Kaoru SHIBATA: shibata.kaoru@ jaea.go.jp
Takashi ITO: itou.takashi@jaea.go.jp
Dick MISCHKE (English Editor): mischke@triumf.ca
Junko BEANBLOSSOM (Secretary): beanblossom.junko@jaea.go.jp
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