[Neutron] J-PARC Newsletter #25
arai (J-PARC)
masaarai at hotmail.co.jp
Mon Jul 31 19:40:37 CDT 2006
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J-PARC Project Newsletter
_______ No.25,July 2006_______
High Intensity Proton Accelerator Project proposed jointly
by the Japan Atomic Energy Agency (JAEA) and
the High Energy Accelerator Research Organization (KEK)
http://j-parc.jp/index-e.html
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HEADLINES AND CONTENTS
1. <<Overview>>
.FURTHER DISCUSSIONS ABOUT THE CONSTRUCTION SCHEDULE.
.BUDGET NEGOTIATION STARTED FOR JFY2007.
.J-PARC PAC FOR 50 GEV HELD IN JUNE-JULY OF 2006.
.50-GEV TUNNEL WAS COMPLETED.
2. <<Accelerator Group>>
.THE J-PARC RING RF TEAM IS BREAKING THROUGH MANY
TECHNOLOGICAL DIFFICULTIES
3. <<Nuclear and Particle Physics Group>>
.FIRST PAC MEETING WAS HELD
.NEUTRINO FIRST HORN SUCCESSFULLY TESTED
4. <<Exotic Neutron Science Group>>
.THE 2nd PROGRAM ADVISORY COMMITTEE (PAC) APPROVED
5 PROPOSALS
.THE THERMAL DIFFUSION STUDIES ON LITHIUM-BATTERY BY MEANS
OF 8Li-RNB
5. <<Neutron Science Group>>
.MORE THAN 80 % OF CONSTRUCTION OF THE MATERIALS & LIFE
EXPERIMENTAL FACILITY HAS BEEN COMPLETED.
6. <<Muon Science Group>>
.ALIGNING PLATES AND GUIDE SHIELDS FOR REMOTE-HANDLING
INSTALLATION HAVE BEEN INSTALLED.
7. <<Nuclear Transmutation Group>>
.PRELIMINARY LETTERS OF INTENT FOR TRANSMUTATION EXPERIMENTAL
FACILITY (TEF) WERE RECEIVED
8. <<Radiation Safety Group>>
.THE FIRST EXPERT COMMITTEE MET FOR THE RADIATION SAFETY
ON THE J-PARK NEUTRINO PRODUCTION TARGET
9. <<Control Group>>
.MPS AND PPS HAVE BEEN INSTALLED FOR THE LINAC COMMISSIONING
10. <<Announcement of Symposia and Meetings>>
11. <<Editorial Note>>
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1. <<Overview>> By Shoji NAGAMIYA
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.FURTHER DISCUSSIONS ABOUT THE CONSTRUCTION SCHEDULE.
According to the present construction schedule,
the Linac beam test will start in December of 2006, followed
by the 3 GeV beam test in September of 2007 and the 50 GeV beam
test in May of 2008. All the facilities including neutrons,
muons and hadrons will start their operational runs within
JFY2008, whereas the neutrinos will start at the beginning of
JFY2009 (April of 2009).
Concerning the above schedule, a series of discussions
were held during the past three months. The discussions have
been focused on both technical and financial aspects of the
project. The present conclusion after these discussions is that
both KEK and JAEA take full responsibility to keep the
proposed schedule. It was commonly agreed not only within the
J-PARC group but also at the top levels of both institutions
that the highest priority is to keep the planned schedule for
J-PARC.
In addition, the Management Council of J-PARC held in
June strongly endorsed the present scenario for the schedule of
the project.
Thus, unless the Government changes dramatically the
future funding for J-PARC, the project shall be completed on
schedule in 2008.
.BUDGET NEGOTIATION STARTED FOR JFY2007.
Every year, the July-August period is the busiest
season for the budget negotiation for the next fiscal year,
JFY2007. The highlight of the budget request this time is
to keep the construction budget at KEK and to keep the
pre-operational fund at JAEA. Many reviews have been started
from this month. The project team has been undergoing an
extremely busy time for the preparation of budget materials
towards the next year.
.J-PARC PAC FOR 50 GEV HELD IN JUNE-JULY OF 2006.
The end of April was the deadline for the first call
of proposals for experiments at 50 GeV. About 20 proposals
including a few Letters of Intent were submitted to the J-PARC
Center. The PAC was formed under the Director of the Institut
Of Particle and Nuclear Studies(INPS) at KEK, and the PAC meeting
was held on June 30 - July 2. The result will be transmitted first
to the Director of INPS and, then to the Director of the J-PARC,
before it is announced in public.
.50-GEV TUNNEL WAS COMPLETED.
The construction is still moving vigorously on site.
Concerning the civil construction, the 50 GeV tunnel was
completed at the end of June. Overall, 70% of the construction
was completed for the entire J-PARC.
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2. <Accelerator Group> by Yoshishige Yamazaki
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.THE J-PARC RING RF TEAM IS BREAKING THROUGH MANY
TECHNOLOGICAL DIFFICULTIES
The fast energy ramping is an important feature for
both the J-PARC rings, which should provide high average beam
power by their high repetition rates. For this reason the
accelerating field gradient amounts to 25 kV/m with high duty
factors (50% for RCS and maximum 50 % for MR, respectively) in
contrast to that of typically 10 kV/m in conventional
ferrite-loaded cavities. For this performance the J-PARC is
making use of the accelerating cavities loaded with the magnetic
alloy (MA) rather than conventional ferrite. The J-PARC ring
RF team is breaking through some of the most difficult problems
in order to complete the development in time. Although the MA has
been used in several institutes, either the field gradient or
the average power (sometimes both) is much less than those for
J-PARC. Also, both the resonant frequency and the Q value of
the cavities are optimized by radially cutting the MA cores and
by adjusting the distance between the two cores. After a long
painstaking development, the cores with the cut surface polished
by diamond powder could stand the RF power loading (by 30 % higher
average power than required and the same field gradient) for
several hundred hours. The test is still ongoing, approaching
the tentative goal of 1,000-hour power test.
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3. < Nuclear and Particle Physics Group > by Jun Imazato
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.FIRST PAC MEETING WAS HELD
The first meeting of the Program Advisory Committee
for experiments at the J-PARC 50-GeV proton synchrotron
was held from June 30 to July 2 at the KEK Tsukuba campus.
Presentations were made for 15 proposals both at the Hadron
Experimental Facility and Neutrino Experimental Facility.
The committee evaluated these proposals from the point of view
of scientific merit. Secondary beamlines in the Hadron Hall
were also discussed and day-1 experiments were appointed.
.NEUTRINO FIRST HORN SUCCESSFULLY TESTED
At the neutrino facility, a neutrino beam is
generated from the decay of pions that are produced when
the primary proton beam from the accelerator hits a graphite
target. The intensity of the neutrino beam is magnified by 15
times with an electromagnetic horn system by focusing pions
parallel. The system consists of three horns and will be
operated with 320kA peak current generating 2.1 Tesla maximum
field. The assembly of the 1st horn prototype was completed
in May. Since then, it has been tested with a pulsed current.
The current was increased step by step while checking the
temperature rise due to Joule's heating, and distortion by
Lorentz force. The rated current of 320kA has recently
been achieved without any serious trouble. This met one of
the big milestones of the neutrino beam project. (The sound
produced by the Lorentz force is so big that one cannot
stand nearby without ear-plugs.) A long-term test to check
troubles caused by fatigue will start soon.
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4. < Exotic Nuclear Science Group > by Hiroari Miyatake
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.THE 2nd PROGRAM ADVISORY COMMITTEE (PAC) APPROVED
5 PROPOSALS.
The Tokai Radioactive Ion Accelerator Complex (TRIAC)
PAC was held this January and approved continuations of
following 4 subjects: (1) A study of the heavy element
synthesis in the early universe using 8Li-radioactive
nuclear beams (RNB). (2) Nuclear spectroscopy of spin-polarized
nuclei in the region of 132Sn. (3) Spin-polarization of indium,
cesium, barium isotopes with a tilted-foil method and
measurements of their nuclear magnetic moments. (4) Coulomb
excitation spectroscopy of radioactive xenon. In addition,
a new proposal on (5)the study of lithium-ion diffusion in
superionic conductors was also approved. KEK and JAEA will
jointly steer the TRIAC machine-time schedule for those
subjects up to the end of FY2006.
Please visit[http://triac.kek.jp]
or contact [sunchan.jeong at kek.jp]
for further submission of experimental proposals.
.THE THERMAL DIFFUSION STUDIES ON LITHIUM-BATTERY BY MEANS
OF 8Li-RNB
After the measurement of the Li-ion diffusion constant
in the beta-LiGa, which is one of possible electrode materials,
experiments have moved to the measurements of lanthanum lithium
titan oxide (LLTO), which is an important material as a possible
solid electrolyte in the lithium-ion battery. In the first
measurement, the typical 8Li-RNB intensity was 20 kHz and
measured temperature range was 20 to 80 Celsius. The sample
materials containing various atomic compositions of lanthanum and
lithium will be measured in the further experiments.
.THE 24Sn(d,p)125Sn* REACTION AS A FEASIBILITY TEST OF
THE NEUTRON CAPTURE REACTIONS HAS BEEB PERFORMED.
The neutron capture reactions of around 132Sn are
key to determine the path of the astrophysical rapid neutron
capture process. In the case of the direct radiative neutron
capture reaction, the cross section can be determined by a
corresponding neutron transfer reaction. As a test of the
experiment, 124Sn(d,p)125Sn* reactions in the inverse
kinematics by using CD2 target and 3.7 MeV/u 124Sn beams
has been performed at the JAEA tandem facility. Obtained
proton energy spectrum was almost free from the background
to assign excited states in 125Sn. Further analysis is
in progress.
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5. <<Neutron Science Group>> by Yujiro IKEDA
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.MORE THAN 80 % OF THE CONSTRUCTION OF THE MATERIALS & LIFE
EXPERIMENTAL FACILITY HAS BEEN COMPLETED
In the 1MW spallation neutron source facility
construction, the following items have progressed almost on schedule;
23 shutter gates have been installed; inserts of the Helium vessel
beam windows were placed by using a remote handling device;
a factory test of the low temperature hydrogen circulation
pump was made successfully; cryogenic moderator prototype
fabrication test was carried out with reasonable performance;
the mercury target inner and outer vessel manufacturing has
been in progress, etc. More than 80 % of the Materials & Life
Experimental Facility building has been completed. The temporary
opening at the central section, which separates two experimental
halls, is now to be closed after finishing all scheduled heavy
components installation. To assure requested accuracy in the pulse
timing, a scheme was investigated by the neutron group in close
communication with the accelerator group. The extended buildings
for a residual stress analysis diffractometer is funded
and under design. The development of a high speed disc chopper
has been underway. To keep the cost as low as possible, the neutron
beam line shielding criteria were re-evaluated. A prototype of
the data acquisition system was tested for 6 months by users before
the shutdown of the KENS facility in KEK. The result was
satisfactory. The MSGC development has progressed remarkably
achieving the worlds highest performance in terms of the spatial
resolution. It was confirmed that a newly developed
ZnS:Ag/B2O3 scintillator has twice as much neutron detection
efficiency as compared to the existing ZnS:Ag/LiF.
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6. < Muon Science Group > by Yasuhiro Miyake
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. ALIGNING PLATES AND GUIDE SHIELDS FOR REMOTE-HANDLING
INSTALLATION HAVE BEEN INSTALLED.
In the M2 line, taking into account the alignment
of the heavy and tall magnets and the target chamber by remote
handling from the maintenance area at 4 m above the floor level,
we installed 40 sets of alignment plates with a precision
XY +-0.1 mm and Level +-0.1 mm, from the beginning of February 2006
to the beginning of April 2006 on the 70 mm thick baseplates.
The alignments plates are equipped with knock pins which allow
precise positioning of the beam line components such as magnets,
guide shields, target chamber and pillow seals. Due to strong
requirements from the safety group, all the holes and gap were
epoxy coated to prevent any water leakage. We are now installing
32 sets of guide shields towards the knock pins on the alignment
plates. The guide shields are made of iron and equipped with
a guiding rail structure for the installation of each of the heavy
components as well as guide rails for the pillow seal assembly.
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7. <<Nuclear Transmutation Group>> by Hiroyuki OIGAWA
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.PRELIMINARY LETTERS OF INTENT FOR TRANSMUTATION
EXPERIMENTAL FACILITY (TEF) WERE RECEIVED
The Project Team has received about 30 of
"Preliminary Letters of Intent (Pre-LOIs)" for experiments
at the Transmutation Experimental Facility (TEF). They are now
being tallied and categorized. Additional submission of Pre-LOI
is still acceptable.
Please refer to the web site:
http://j-parc.jp/index-e.html ,
and click "call for the preliminary Letters of Intent"
in the column of "News & Topics".
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8. <Radiation Safety Group> by Taichi MIURA and Hiroshi NAKASHIMA
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.THE FIRST EXPERT COMMITTEE MET FOR THE RADIATION SAFETY
ON THE J-PARK NEUTRINO PRODUCTION TARGET
The 1st Expert Committee on the safety of the J-PARC
neutrino production target was held on 28th June, 2006. In the
committee, overviews of the neutrino project, facilities,
and the construction schedule were presented. The committee
has concluded that the safety aspects of the following 7 items
will be mainly reviewed: (1)superconducting magnet system;
(2)radioactivity induced in cooling water and He gas used in
the secondary beam line and the exchange process; (3)carbon
target system; (4)maintenance and replacement of the target
and the horn, and the storage scheme; (5)interlock scheme for
neutrino production system; (6)the safety system management
and safety control system for the neutrino experimental
facility; (7) radiation safety during the commissioning of
the 50 GeV synchrotron. This committee is scheduled to meet
about 6 times until May, 2007. From the 2nd through 5th
committees, 7 items above will be examined, and in the 6th
committee the final report will be brought out. In the past,
the Safety Deliberative Committee on Radiation Safety has been
held as the advisory committee for two organizations of JAEA
and KEK. The Safety Deliberative Committee will also play the
role of the committee for J-PARC radiation-safety and is
planning to be held on 4th July.
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9. <Control Group>by Tadahiko Katoh
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.MPS AND PPS HAVE BEEN INSTALLED FOR THE LINAC COMMISSIONING
The progress in the control system seem to be very
slow and it is very difficult to put an end to the work. The system
construction is being done steadily. Machine protection System (MPS)
and Personnel Protection System (PPS) have been installed and
inspected for the coming commissioning of the linac. MPS and PPS
are both key systems to protect the accelerator itself and personnel
from radiation hazards. These systems should be completed before
the accelerator operations begin due to the legal regulations.
Software installation for the linac commissioning have also been
done by defining relational database structure and entering
necessary information into the database. Some application programs
are generated by using the database successfully. Software for
the operations is expected to be accumulated as the commissioning
progresses.
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10. Announcement of Symposia and Meetings
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Advisory Workshop for Engineering Diffractometer,
11-12 October
contact: suzuya.kentaro at jaea.go.jp
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11. <<Editorial Note>>
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Editorial Board:
Masatoshi ARAI (chair): masatoshi.arai at j-parc.jp
Koji YOSHIMURA: koji.yoshimura at kek.jp
Yujiro IKEDA: yujiro.ikeda at jaea.go.jp
Nobuo OUCHI: nobuo.ouchi at jaea.go.jp
Shinya SAWADA: shinya.sawada at kek.jp
English Editor: Dick Mischke mischke at triumf.ca
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