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J-PARC Project Newsletter
No. 41, July 2010
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]
BEAM POWER IS STEADILY GROWING.
A NEW SUPPLEMENTAL BUDGET WAS APPROVED BY JAEA.
BUDGET REQUEST STARTED.
REPORT FROM INTERNATIONAL ADVISORY COMMITTEE ARRIVED.
J-PARC OPEN HOUSE.
2. [Accelerator Division]
ACCELERATOR KEEPS AVAILABILITY HIGHER THAN 92 % IN USER OPERATIONS
FOR NEUTRON, MUON AND NEUTRINO.
3. [Nuclear and Particle Physics Division]
INSTALLATION OF K1.1BR ALMOST FINISHED.
INSTALLATION OF THE KOTO DETECTOR STARTED.
OPEN HOUSE.
T2K ACCUMULATED PHYSICS DATA SUCCESSFULLY BEFORE SUMMER SHUTDOWN.
4. [Materials and Life Science Division]
THE NEUTRON SOURCE WAS RESUMED ON MAY 9 AFTER A TROUBLE IN THE
CRYOGENIC HYDROGEN SYSTEM IN FEBURUARY.
USER OPERATION FOR FY2010 HAS STARTED IN JUNE.
THE FIRST WORKSHOP ON THE MUON INSTRUMENTS "MUSE" WAS HELD ON
JUNE 3-4, 2010.
5. [Exotic Nuclear Science Group]
DIRECT MEASUREMENTS OF 8LI(4HE,N)11B REACTIONS AT TOKAI RADIOACTIVE
ION ACCELERATOR COMPLEX (TRIAC).
6. [Nuclear Transmutation Section]
HOW MANY BEAM TRIPS ARE ACCEPTABLE FOR THE ADS REACTOR COMPONENTS?
7. [Safety Division]
APPLICATION FOR LICENSES OF THE OPERATION OF THE WHOLE FACILITY WERE
SUBMITTED TO THE MINISTRY OF EDUCATION, CULTURE, SPORTS, SCIENCE AND
TECHNOLOGY (MEXT) ON JUNE 24.
8. [Editorial Note]
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1. [Overview] by Shoji NAGAMIYA
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BEAM POWER IS STEADILY GROWING
The accelerator is running steadily these days to provide beams.
The neutron moderator had a problem due to helium leakage into liquid
hydrogen, but by bypassing the helium reservoir the neutron target is
now running well. Unfortunately, because this neutron source cannot
accept intensity higher than 120kW, the 3GeV machine is running at the
level of 120kW. In the summer the entire system will be replaced in
order to accept higher intensity proton beams at 3GeV. At the Main
Ring, the intensity went up to 100kW for a short period of time.
Here, already 22 events were recorded in Super-Kamiokande by May of
2010 after the first detection of February 24th.
A NEW SUPPLEMENTAL BUDGET WAS APPROVED BY JAEA
At the end of June it was announced that, with a new budget
framework (to accelerate large projects), a funding of 48 OkuYen
(approximately $50M) was granted for the Linac, 3GeV and for a
neutron source, in order to upgrade to the 1MW level. Already, the
400MeV Linac construction is in progress. Therefore, this additional
budget is extremely useful for the 1MW upgrade. The budget starts
this year for three years until JFY2012.
BUDGET REQUEST STARTED
The budget season has started. The request toward JFY2011 is
under serious negotiation now. The J-PARC Center proposed an 8
cycle operation for JFY2011 (note 9 cycles are a full 200 days).
In addition, the ultra slow muon channel, main ring shield,
high momentum beam line, together with a neutron beam line have
been proposed. Also, the completion of the 400 MeV linac, etc.,
are lining up.
REPORT FROM INTERNATIONAL ADVISORY COMMITTEE ARRIVED
This year, the report arrived late in June. The committee
congratulated the success that all the elements are running nicely.
On the other hand, the committee pointed out much smoother
organizational structure by having mirror image of the two
organizations. In addition, the most urgent issue is to go to
1MW as quickly as possible. It was pointed out to us that the
financial arrangement must be planned carefully and, at the same
time,rigorously.
J-PARC OPEN HOUSE
On August 28, the J-PARC Open House will be held. This is
the third one. Two years ago we had 2,600 visitors and the
last year we had 4,600 visitors. We are preparing for a large
number of visitors, again this year.
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2. [Accelerator Division] by Ainosuke ANDO
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HIGH AVAILABILITY IN MLF (MATERIAL AND LIFE SCIENCE FACILITY)
AND NEUTRINO COMMON USE OPERATIONS
The first period of the 2010 user run (Run #32 / April~ #34 / June)
ended on 26th June. The availability in this period was 92.1 % for
MLF and 92.7 % for the neutrino experiment.
NEW EXTRACTION KICKERS FOR THE MR (MAIN RING / 50 GEV SYNCHROTRON)
The installation of new kickers is in progress in the MR. These are
ready not only for eight-bunch operation but also for beam heating.
The longitudinal coupling impedance is drastically reduced to one
twentieth and estimated ready for the beam intensity of 750 kW from the
thermal aspect.
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3. [Nuclear and Particle Physics Division]
by K.TANAKA, T. KOMATSUBARA, T.TAKAHASHI and T.TSUKAMOTO
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INSTALLATION OF K1.1BR ALMOST FINISHED (by K.H.TANAKA)
The installation of the low momentum separated beam line, K1.1BR,
has been proceeding on the south side of the T1 target, and piping of
cooling water and power wiring were also almost completed. The big
event was the mounting of D1 in the vacuum vessel, Pentagon, as the
last element due to go into the tank. D1 is a C-type magnet capable
of excitation for the future beam operation of K1.1 with more than
1.1 GeV/c, however, the field distribution was optimized for the
current nominal operation of K1.1BR of 0.8 - 1.1 GeV/c. The magnet
is super-radiation-hard with only inorganic components and with
tin-impregnated indirect water-cooling coils. Its high performance is
expected as the same type rad-hard magnets in the K1.8 side.
The electrostatic separator installed is a recycled one from the
KEK-PS North Hall. The separator was tested for high-voltage operation
in advance (+/-400 kV 20 Hr operation) and was proven sound.
The oil-insulation system will be upgraded in the near future to the
oil-less dry-ceramic insulation system developed by us. The beam
line is equipped with three slit systems of the internal focus (IFS),
the mass slit (MS1) and the last horizontal slit (HFOC), which were
all newly made and are functioning very well. The total beam line will
be soon powered on in order to check the field characteristics,
cooling performance, interlock system, etc. and made ready for
the beam commissioning scheduled in the coming October.
INSTALLATION OF THE KOTO DETECTOR STARTED (by T. KOMATSUBARA)
In the last fiscal year, a new neutral beam line for the E14 KOTO
experiment (experimental study of the decay of a long-lived neutral
kaon into a neutral pi meson and a pair of neutrinos) was constructed
to the Hadron Hall. Neutral kaons in the beam were successfully
confirmed during the beam survey. This year, the KOTO collaboration
proceeds to the construction of the experimental area and the
installation of the detector. The main part of the KOTO detector is
the electromagnetic calorimeter, with the diameter of 1.9m and
consisting of 2,700 inorganic scintillating crystals of undoped
cesium iodide (CsI), to measure two photons from neutral pi meson.
They will build the calorimeter with the 2.5cm x 2.5cm x 50cm and
5.0cm x 5.0cm x 50cm CsI crystals used in the past in the KTeV
experiment at Fermilab, USA. A prototype calorimeter was tested
in early 2010 at the electron-beam facility of Tohoku University,
Sendai, Japan. In June, they started stacking the CsI crystals
in the container located within the dehumidified room in the
experimental area. During the beam time of J-PARC slow extraction
in this autumn, they expect to perform an engineering run of the
CsI calorimeter.
OPEN HOUSE (by T.TAKAHASHI)
The 3rd J-PARC Open House will be held on August 28, the last
Saturday of the Summer Holidays in schools. In the Hadron Hall,
a newly constructed K1.1BR beamline, in addition to the K1.8BR,
K1.8, and KL areas can be seen from the gallery level. Panels on
the experiments will be also exhibited.
T2K ACCUMULATED PHYSICS DATA SUCCESSFULLY BEFORE SUMMER SHUTDOWN
(by T.TSUKAMOTO)
T2K accumulated neutrino beam data corresponding to
3.35e+19 PTO(proton on target) with beam operation until June 26
and 22 neutrino events have been observed by Super-Kamiokande by
the analysis so far with data accumulated through the middle of May.
The recent T2K status was reported at the Neutrino 2010 which was
held at Athens, Greece ( http://www.neutrino2010.gr/ ) and also will
be presented at ICHEP 2010 which will be held at Paris, France
(http://www.ichep2010.fr/ ). Analysis is being carried out for full
data set collected through the end of June.
There will be a shutdown and maintenance period for the neutrino
beam facility and the near detector ND280 until the end of October,
and the beam operation with higher power than 100kW is planned from
November. Many maintenance works will be done for more stable
operation of the neutrino beam facility, and the barrel ECALs, which
are the remaining ND280 sub-detectors, will be installed in this
shutdown period.
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4. [Materials and Life Science Division] by Masatoshi ARAI
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THE NEUTRON SOURCE WAS RESUMED ON MAY 9 AFTER A TROUBLE IN THE
CRYOGENIC HYDROGEN SYSTEM IN FEBRUARY
USER OPERATION FOR FY2010 HAS STARTED IN JUNE
THE FIRST WORKSHOP ON THE MUON INSTRUMENTS "MUSE" WAS HELD ON
JUNE 3-4, 2010
1. Neutron Source
The user service operation was resumed on May 9 after a halt due
to a trouble found in the cryogenic hydrogen system in February 2010.
Two-cycle operation at 120 kW for 37 days in total was executed
successfully in May and June with keeping beam availability over
90%. During the summer maintenance period, the accumulator that is
the cause of the trouble will be replaced with a new one for full
recovery. The algorithm of the automatic procedure to tune the proton
beam orbit was improved substantially. As a result, the orbit can
be adjusted to an optimal path easily all along the beam line from
3-GeV RCS to MLF. The contract was made with the vendor to fabricate
a new compact-type target vessel with He bubblers to mitigate pressure
waves. The new target will be installed in the 2011 summer shutdown
period.
2. Neutron Science
20-days beamtime in May was used for accepted proposals in 2009B
due to the trouble in the cryogenic hydrogen system in February.
From June 2010 to March 2011, 110-days beamtime will be available
in total: 50 days for 2010A (the first half of FY2010) and 60 days
for 2010B (the last half of FY2010). User operation for the 2010A
period has been started on June 7. In the 2010A period, 74 accepted
general proposals (called by J-PARC) as well as about 20 general
proposals (called by Ibaraki prefecture) are being carried out from
June to November. For 2010B proposals, 87 proposals to J-PARC and 22
to Ibaraki are submitted, and they are being reviewed in science,
safety and technical viewpoints.
In July, the construction of 4 new instruments,
DNA (BL02, Inverted Geometry Spectrometer), TAIKAN (BL15, SANS),
VNR (BL17, Vertical Reflectometer) and SENJU (BL18, Single Crystal
Diffractometer), and the construction of the dedicated building for
NPD (BL09, Powder Diffractometer) are started. The construction of
PLANET (BL11, High Pressure Diffractometer) is continued.
A workshop on "Neutron Scattering and Computing" was held on 12
April to discuss collaboration with computer centers in KEK and JAEA.
More than 50 people got together and found concrete issues to be
worked together.
In order to encourage scientific activities of the in-house staff
of the MLF division, a monthly regular seminar programme under the
auspices of the Quantum Beam Science Directorate, the Advanced
Research Science Center of JAEA and the Institute of Materials
Structure Science of KEK has been started.
3. Muon Science
We are making a sustained effort to develop a new data
acquisition (DAQ) system and a new detector technology utilizing
multi-pixel photon counter (MPPC) devices for the muSR experiments
in order to undertake muSR experiments under the extremely high muon
event rate expected when the proton beam power will reach 1MW in
the future. During the beamtime period May-June, 2010, we have been
working on coding to adapt newly developed hardware, such as the
Copper-Lite board, collaborating with the KEK computing research
center. Along with this effort, the message exchange mechanism
of the DAQ system was drastically simplified to reduce overhead
on the communication between the multiple components.
The first workshop to present experimental results performed
at the muon instruments (MUSE), was held at Tokai on June 3, 2010.
At the workshop, we had fourteen activity reports from the MUSE
users extensively in the field of material science, magnetism,
chemistry, non-destructive element analysis and particle physics, etc.
On June 4, 2010, the first workshop on the technical development
achieved at MUSE was held, celebrating that the MUSE construction
team was awarded the Special Prize from the Foundation for High Energy
Accelerator Science.
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5. [Exotic Nuclear Science Group] by Hiroari MIYATAKE
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DIRECT MEASUREMENTS OF 8LI(4HE,N)11B REACTIONS AT TOKAI RADIOACTIVE
ION ACCELERATOR COMPLEX (TRIAC)
The 8Li(4He,n)11B reaction is considered to be one of key reactions
to synthesize heavier elements under an explosive environment in the
universe. In our past measurements, we observed a resonance-like
structure in the excitation function of the reaction cross section at
astrophysical energy, which leads to an enhancement of the reaction
rate. We tried to measure the cross sections in the energy region of the
astrophysical interest with higher statistics by one order of magnitude
at TRIAC to reveal the fine structure around the resonance. In the
experiment, we utilized a newly developed active target type detector,
multiple-sampling and tracking proportional chamber with a gas
electron multiplier (GEM-MSTPC) under the direct injection of the
tens of kHz beam. The detailed analysis is in progress.
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6. [Nuclear Transmutation Section] by Hirofumi TSUJIMOTO
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HOW MANY BEAM TRIPS ARE ACCEPTABLE FOR THE ADS REACTOR COMPONENTS?
In addition to the development of the Transmutation Experimental
Facility (TEF), the Transmutation Section of J-PARC Center is also
conducting the design study on the future Accelerator-Driven System
(ADS) for transmutation of long-lived nuclear wastes through
cooperation with the Research Group for Nuclear Transmutation
Technology of the Nuclear Science and Engineering Directorate, JAEA.
In the design study of ADS, frequent beam trips as experienced in
existing high-power proton accelerators are considered problematic
because they may cause thermal fatigue in ADS components. Thermal
transient analyses were performed to investigate the effects of beam
trips on the reactor components, with the objective of formulating
feasible ADS design concept and determining the requirements for
accelerator reliability. Our results indicated that the acceptable
beam-trip frequency was classified by three criteria according to the
beam trip duration, T: 20,000 times per year for 0 < T < 10 s, 1,000
times for 10 s < T < 5 min, and 47 times for T > 5 min.
These criteria, especially those for 10 s < T, cannot be
satisfied if we adopt the today's accelerator technology as it is.
In order to consider the measures to reduce the beam trip frequency of
the high power accelerator for ADS, we have started investigating the
beam trip phenomena of existing accelerators. From this point of view,
the J-PARC Linac is expected to provide very valuable operation data,
which can be used to improve the accelerator reliability.
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7. [Safety Division] by Taichi MIURA
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APPLICATION FOR LICENSES OF THE OPERATION OF THE WHOLE FACILITY WERE
SUBMITTED TO THE MINISTRY OF EDUCATION, CULTURE, SPORTS, SCIENCE AND
TECHNOLOGY (MEXT) ON JUNE 24
The main change topics are the power-up for the whole facility
(except Hadron Facility(HD)), the new secondary beam lines in Materials
and Life Science Facility, and shielding reinforcement for a
primary-beam dump and the shielding re-arrangement procedure for the
experimental areas in HD.
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9. [Editorial Note]
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Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto@kek.jp
Fujio MAEKAWA: maekawa.fujio@jaea.go.jp
Takashi ITO: itou.takashi@jaea.go.jp
Dick MISCHKE (English Editor): mischke@triumf.ca
Chikako KAIBARA (Secretary): kaibara.chikako@jaea.go.jp
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