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J-PARC Project Newsletter
No.34, October 2008
Japan Proton Accelerator Research Complex under construction
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]
ANOTHER MILESTONE MARKED IN SEPTEMBER
J-PARC OPEN HOUSE
MANY APPLICATIONS FOR THE USAGE OF MLF FACILITY
NEW SCHEME FOR THE OPERATION OF THE NEUTRON FACILITY
CEREMONY FOR MLF AND NEW BUILDING FOR USERS
NOBEL PRIZES AWARDED TO THREE JAPANESE PHYSICISTS
2. [Accelerator Division]
RCS GENERATED A BEAM POWER OF 210 KW AND DEMONSTRATED
THE 352-KW OPERATION
3. [Nuclear and Particle Physics Division]
HADRON HALL IS APPROACHING THE FIRST BEAM DELIVERY
CONSTRUCTION OF NEUTRINO FACILITY
4. [Materials and Life Science Division]
NEUTRON BEAM COMMISSIONING AGAIN STARTED WITH TWO
ADDITIONAL INSTRUMENTS: 4SEASONS(HIGH INTENSITY CHOPPER)
AND TAKUMI(HIGH INTENSITY ENGINEERING DIFFRACTOMETER)
THE FIRST MUON BEAM WAS SUCCESSFULLY EXTRACTED ON
SEPTEMBER 26 AT THE J-PARC MUON SCIENCE FACILITY (MUSE)
5. [Nuclear Transmutation Section]
EXPERIMENTAL FACILITY TO BE REALIZED IN PHASE II?
LEAD BISMUTH TARGET DEVELOPMENT
6. [Safety Division]
THE SAFETY INSPECTION OF MLF SUCCESSFULLY CONDUCTED
BY NUSTEC
7. [Announcement of Symposia and Meetings]
8. [Editorial Note]
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1. [Overview] by Shoji NAGAMIYA
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ANOTHER MILESTONE MARKED IN SEPTEMBER
On September 26 of 2008, another milestone was achieved by
having muon beams in an experimental area. Details will be
described later in this Newsletter. The group succeeded in
measuring the 2.2 micro-second lifetime together with a clean
signal of muon spin rotation in a magnetic field. The muon
group will open their facility to users from December of
this year; the neutron group will also open its facilities to
users. As reported in a special issue of the Newsletter at the end
of September, beam intensities higher than expected were attained.
This fact will boost up the muon program from December, similarly
for the neutron program.
J-PARC OPEN HOUSE
On August 10th, the entire J-PARC facilities were shown to the
public by having a special Open House Day. An anticipated number
of visitors was less than 1,000, whereas the actual number of
visitors was 2,600. Over 500 came from outside the Ibaraki-Prefecture;
most of them are from Tokyo.
Once a year (most likely in early August) we plan to have an Open
House, since the previous one was well received by the public.
MANY APPLICATIONS FOR THE USAGE OF MLF FACILITY
At the end of August the first-round of applications for the
usage of MLF (Materials and Life Science Experimental Facilities)
was closed. Many research groups applied for both neutron and muon
programs, exceeding what we can provide within this fiscal year
by approximately a factor of two. The Committee was formed and it
is examining the proposed programs.
NEW SCHEME FOR THE OPERATION OF THE NEUTRON FACILITY
As described in the previous Newsletter, a new scheme to allow
funding for the operation of the neutron programs is now under serious
discussion inside the Government. A first draft for the new law was
created and it is being discussed. Also, both KEK and JAEA started to
discuss rather seriously the operating system of this portion of the
fund. It is anticipated that this new law will be discussed in the
Diet from January or February of 2009.
CEREMONY FOR MLF AND NEW BUILDING FOR USERS
On December 16th a ceremony is scheduled in Tokai to celebrate the
opening of the MLF facilities to public users and to celebrate the
opening of a new building that is owned by the Ibaraki Prefecture.
It is anticipated that J-PARC users can use office space in this new
building.
NOBEL PRIZES AWARDED TO THREE JAPANESE PHYSICISTS
The J-PARC members would like to congratulate Professors Y. Nambu,
M.Kobayashi and T. Maskawa for the extraordinary prize. The J-PARC
plans to study the origin of the nucleon mass in the Hadron
Experimental Hall by the study of the mechanism of spontaneous chiral
symmetry breaking, which was predicted by Professor Nambu over 40
years ago. An expansion of the Kobayashi-Maskawa Theory from the quark
sector to the lepton sector implies a mixing among leptons.
The neutrino program at J-PARC is encouraged very much by the prize
this year. In addition, a precise measurement of CP violation in
the kaon sector is also planned at J-PARC. In addition to the
relevance of the J-PARC physics to the work done by three eminent
physicists, the J-PARC has many personal relations to the three Nobel
Laureates this year. Again, congratulations from all of us to the
three Laureates.
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2. [Accelerator Division] by Ainosuke ANDO
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RCS GENERATED A BEAM POWER OF 210 KW AND DEMONSTRATED
THE 352-KW OPERATION
At 11:00am on September 18th, the Rapid Cycling Synchrotron (RCS)
generated the beam power of 210 kW (1.77E13 protons per pulse) to the
3-GeV beam dump at 25-Hz operation for a period of 70 seconds, which
is limited by the 4-kW capacity of the dump. Although the beam loss
amounted to 3%, the loss was concentrated at the 181-MeV injection
and also at the collimators. This operation was done without
transverse or longitudinal painting at injection.
The longitudinal painting at injection was performed by controlling or
scanning both the injection timing of the chopped beam from the LINAC
and the RF frequency. This was very powerful for high intensity. A
pulse of 2.6E13 protons was extracted to the 3-GeV dump with the beam
loss less than 1%. This intensity corresponds to 315 kW if operated
at 25 Hz. A pulse of 2.93E13 protons which corresponds to 352 kW was
also extracted but the beam loss near the middle of acceleration curve
amounted to about 3%. This agrees with the estimation from the
present RF power. The number of RF cavities must be increased from 10
to at least 12 to realize 300 kW output with 181-MeV injection.
There are some problems in the transverse painting at injection caused
by nonlinear resonances. The “150 pi mm-mr. painting“ ( which means
the final emittance of 150 pi mm-mr.) was successfully performed by
the careful selection of transverse tunes. The ionization profiles
showed that there was good agreement in profiles between the
painted beam and the high power beam without painting. That is, our
method is natural. In MR (50 GeV Synchrotron), the 30-GeV acceleration
and extraction is scheduled from this December, and the preparations
proceed as scheduled.
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3. [Nuclear and Particle Physics Division]
by J. Imazato, T. Tsukamoto
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HADRON HALL IS APPROACHING THE FIRST BEAM DELIVERY
Towards the delivery of the first slow-extracted proton beam soon,
the Hadron Hall is almost over the peak of equipment installation.
In the large vacuum vessel just downstream of the T1 target, the
front elements of the secondary beam line, K1.8 and the collimator
with overhead shielding now sit. The construction of the beam dump has
been completed. The primary line magnets with the chimney structure
were all installed and have been tested with full currents.
The T1 target is being placed in position after the final tuning in
the factory. The beam line has been equipped with the vacuum system
and beam monitors. The preparation of the secondary beamline is
proceeding in parallel. The K1.8BR beam line, which is due to be the
first secondary beam, is now in the final phase of magnet installation.
The new ES (Electro-Static) separator was transported from Tsukuba
after the HV testing there, and it has been conditioned in Tokai
and will be installed soon. The experimental area used for the Day-1
experiment is now being arranged with necessary installations.
The experimental group started the preparation of detector installation
aiming for using the first secondary beam early next year. The next
experimental area to be provided with the secondary beam is K1.8
where a series of hypernuclear experiments are planned. The SKS
spectrometer has recently been transported in parts from the KEK-PS
counter experimental hall in Tsukuba. Waiting for the modification
of the super-conducting He cooling system with small GM refrigerators
in a factory, the total system will be reconstructed next year
to be ready for the experiments at K1.8.
CONSTRUCTION OF NEUTRINO FACILITY
The NU2(Neutrino Utility building 2) and TS(Target Station) became
available following NU1 for equipment installation at the beginning of
September. Magnet power supplies are being installed in NU1 and NU2.
In TS many installation projects are being carried out such as the first
horn system, concrete blocks for the service pit shield and helium
vessel
piping.
All the magnets for the neutrino beam line have been installed in
the neutrino beam tunnel. Connection of cables and pipes, surveys and
other checks are being carried out. Beam monitors are being installed,
which will be finished in October.
Construction of NU3, the pit for the BD(Beam Dump) and MUMON
(Muon Monitor) and NM(Neutrino Monitor) is being carried out well.
BD assembly is being done and BD will be installed in the pit by the
end of October.
The second horn was delivered from the United States in July and is
being tested at KEK as was done for the first and third horns. The test
will be finished in October, then the second horn will be transported to
J-PARC for installation.
The on-axis neutrino detector(INGRID) construction was started
in August. Scintillator bars are being glued to be planes which will be
interleaved by iron planes to make an INGRID module. The first batch of
INRGID detector structure is scheduled to be delivered from France in
February 2009. then the scintillator planes will be installed into the
iron structure to make a module.
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4. [Materials and Life Science Division] by Yujiro IKEDA
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NEUTRON BEAM COMMISSIONING AGAIN STARTED WITH TWO
ADDITIONAL INSTRUMENTS: 4SEASONS(HIGH INTENSITY CHOPPER)
AND TAKUMI(HIGH INTENSITY ENGINEERING DIFFRACTOMETER)
THE FIRST MUON BEAM WAS SUCCESSFULLY EXTRACTED ON
SEPTEMBER 26 AT THE J-PARC MUON SCIENCE FACILITY (MUSE).
1. Neutron Source
During the summer shutdown period in July and August, thermal
insulation performance of a pair of hydrogen pumps in the cryogenic
hydrogen circulation system was improved to enhance the system
redundancy. As a result,the system now can be operated with a single
pump even at the rated 1-MW power of JSNS. The general control
system of MLF (MLF-GCS) was improved based on the results of the
commissioning tests and modified for the muon target system operation
that is beginning in September. Demonstration tests of the cutting
machine for irradiated components were performed using the mockups
of the moderator vessels and the proton beam window.
The cutting machine will be modified according to these results.
The magnets in the proton beam transport line were surveyed in terms
of alignment. Most of the magnets were found to have sunk since July
2007, when the magnets and the beam monitors were aligned the last
time. The maximal amount of subsidence was ~7 mm near the construction
site of the neutrino facility. The magnets and the beam monitors were
aligned again with the accuracy of ~0.1 mm. The bid of the second
mercury target vessel was awarded to a vendor and the fabrication will
be finished by the end of 2009. The design of a new generation target
vessel is now going on. The target vessel will be separated into
two parts, i.e. the forward and the rear parts, to reduce the waste
volume at the target vessel. The vibration of the target vessel due to
proton beam injection was measured using a laser Doppler vibrometer.
The sound velocity of pressure waves in mercury was evaluated.
2. Neutron Science
Since the last commissioning in June, two more instruments
joined in the commissioning suite in September. These are a high
intensity chopper instrument, 4SEASONS, and an engineering
diffractometer,TAKUMI. Although most of components are aligned,
4SEASONS is waiting for the delivery of a chopper system from
the SKF company in mid-October. TAKUMI has started a test on
a new scintillation detector system developed under a
collaboration with ISIS.
Now seven instruments were under commissioning altogether in
September. In the beam time in September further commissioning
activities were intensively performed on detector, chopper, data-
acquisition system/software, etc. Meanwhile, we encountered a
trouble in the neutron shutter system of the beam line 20
(BL20,Ibaraki powder diffractometer), which will be sorted out
before the next beam time in October.
3. Muon Science
The vacuum connections and the installation of radiation
shields for the decay muon beam line were finished the day before
the first proton beam was delivered to MLF after the long summer
shut down.
A muon production target was inserted into the target position
of the proton beam line in the afternoon of September 19. After
commissioning the beam line magnets, which include the
superconducting solenoids, the DC-separator, quadrupoles and bending
magnets, the background-free muon beam was successfully delivered
through the D1 beamline at 12:10pm on September 26, 2008 (JST).
Positive muons with a momentum of 29 MeV/c were stopped in an
aluminum plate placed at the heart of the muSR spectrometer
(brought from KEK-MSL after refurbishment), and the positron
events were recorded by a brand-new data acquisition system to
monitor the asymmetry. The build-up of events and associated
sharpening of the precession signal under a weak transverse
field was witnessed by some one hundred audience members gathered
at the experimental area, and celebrated the re-birth of the
pulsed muon beam and the achievements made by the J-PARC
Muon Team.
4. User program for MLF use
98 experimental proposals have been received for the MLF
user program from December 17, 2008 to February 28, 2009. The first
program review committee meeting for both neutron and muon uses are
to be carried out very soon.
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5. [Nuclear Transmutation Section] by Kenji KIKUCHI
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EXPERIMENTAL FACILITY TO BE REALIZED IN PHASE II?
The Atomic Energy Commission of Japan commenced the check and
review on the nuclear transmutation technology at the Review Session
on Partitioning and Transmutation Technology and the first meeting
was held on September 19, 2008. The Review Session plans to
investigate the present status and the future prospects on the
nuclear transmutation technology by the end of this year, and
then will make a report after several meetings. This is an important
step
for recognizing scientific value of basic experiments on accelerator
driven
nuclear transmutation in the entire nuclear energy policy at the
Transmutation Experimental Facility proposed in the phase II
construction
of J-PARC.
LEAD BISMUTH TARGET DEVELOPMENT
The international collaboration on the Megawatt Pilot Target
Experiment plans to conduct a post irradiation experiment (PIE) in
order to learn the materials quality after four months of lead
bismuth target operation under 580MeV proton beam injection in 2006.
A PIE meeting was held on 24th September to arrange an acquisition
system of mechanical test data at each of the participating institutes.
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6. [Safety Division]
by Minoru TAKASAKI, Taichi MIURA and Hiroshi NAKASHIMA
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THE SAFETY INSPECTION OF MLF SUCCESSFULLY CONDUCTED
BY NUSTEC
The inspection of secondary beam lines in the experimental
area of the Materials and Life Science Facility (MLF) was successfully
conducted by the Nuclear Safety Technology Center (NUSTEC)
on September 4 and 24, 2008, before and during the operation,
respectively. Now several beam lines in the MLF experimental area
can be officially provided to users for beam experiments.
The application for a license towards the operation of the Nuclear and
Particle Physics Facility (HD) was submitted to the Ministry of
Education, Culture, Sports, Science and Technology (MEXT) on July 25.
Before the submission, several hearings were held about the safe
handling of the experimental area. Through the discussion, mesons and
muons produced by the nuclear interaction of 30 GeV protons were also
defined as radiation to evaluate the radiation safety; in the
radiation protection law (the Law concerning the Prevention from
Radiation Hazards due to Radioisotopes, etc.), these radiations are
not included in the definition of radiation. On July 22 and 24, the
changes in the handling of mesons and muons were explained to the
Ibaraki prefecture government and the Tokai-mura municipal government.
The advisory committee established for the HD facility met on July 29
at the J-PARC site and visited the HD facility to conduct the field
investigation. The application for the operation license of the
neutrino facility is currently underway; on September 30, the radiation
safety review meeting of the neutrino facility, consisting of members
of the J-PARC staff, discussed the safety items presented by the
facility group and approved them; the 6th and the final expert
committee on the safety of the J-PARC neutrino production target is
going to meetin the morning of October 6 to discuss the summary report;
then,the 5th Radiation Safety Committee of J-PARC (the 11th Safety
Deliberative Committee on Radiation Safety of J-PARC) is going to meet
in the afternoon of October 6 to discuss the overall safety aspects of
the neutrino facility.
Assuming a larger 6 quake on the Japanese earthquake scale, a
voluntary emergency drill was carried out at 13:30 on September 18;
in the evacuation area, a roll call was made and the communication
exercises using telephone and FAX were conducted. On September 30,
the Ibaraki prefecture emergency drill was carried out assuming an
accident had occurred at the 2nd nuclear power plant
of Tokai atomic power station; the J-PARC Center participated in the
drill and a roll call was made at the evacuation area.
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7. [Announcement of Symposia and Meetings]
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9th International Workshop on Spallation Materials Technologyあら
(IWSMT9) will be held in 19th-24th October, in Sapporo.
Opening ceremony of MLF facilities to public users will be held on
Dec.16th, 2008 in Tokai.
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8. [Editorial Note]
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+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Editorial Board:
Masatoshi ARAI (chair): masatoshi.arai@j-parc.jp
Yujiro IKEDA: ikeda.yujiro@jaea.go.jp
Nobuo OUCHI: ouchi.nobuo@jaea.go.jp
Shinya SAWADA: shinya.sawada@kek.jp
Toshifumi TSUKAMOTO: toshifumi.tsukamoto@kek.jp
English Editor: Dick MISCHKE mischke@triumf.ca
Secretary: Chikako KAIBARA kaibara.chikako@jaea.go.jp
++++++++++++++++End of Letter+++++++++++++++++++++++++++++++