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J-PARC Project Newsletter
No. 43, Jan 2011
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]
ACCELERATOR IMPROVEMENT IN PROGRESS.
BUDGET WAS ANNOUNCED AT THE END OF 2010.
EXPERIMENTAL PROPOSALS WERE IN DUE.
MAYOR OF TOKAI VILLAGE VISITED ISIS AND CERN.
CONSTRUCTION OF ACCESS ROAD TO J-PARC INITIATED.
NEW DORMITORY WILL BE OPEN ON JANUARY 17TH.
A-TAC AND IAC AND OTHER COMMITTEES TO BE HELD.
2. [Accelerator Division]
THE SCHEDULED MAINTENANCE AND IMPROVEMENTS WERE SUCCESSFULLY FINISHED
3. [Nuclear and Particle Physics Division]
NEW BEAMLINE K1.1BR WAS COMMISSIONED.
OCT. AND NOV. RUN FOR SLOW EXTRACTION SUMMARY.
T2K ACCUMULATED MORE DATA AFTER SUMMER SHUTDOWN.
4. [Materials and Life Science Division]
200 KW OPERATION FOR THE 2010B PERIOD HAS STARTED.
CONSTRUCTION OF SIX NEW INSTRUMENTS IS CONTINUING.
"FLY PASS SYSTEM" WAS NEWLY INTRODUCED TO MUSE FOR THE MuSR
MEASUREMENTS WITH A TINY VOLUME.
5. [Exotic Nuclear Science Group]
THE FIRST OBSERVATION OF LASER RESONANCE IONIZATION OF IRIDIUM ATOMS.
POLARIZED RADIOACTIVE INDIUM BEAM PRODUCED BY TILTED FOILS.
THE REACTION CROSS SECTIONS OF 12C(ALPHA,GAMMA)16O WERE MEASURED
FOR ASTROPHYSICAL INTEREST.
6. [Nuclear Transmutation Section]
DEVELOPED THE ULTRASONIC DOPPLER METHOD FOR FLOW MEASUREMENT
OF LIQUID METAL.
7. [Safety Division]
THE 10TH RADIATION SAFETY COMMITTEE OF J-PARC MET ON DEC. AND THE
PERIODICAL INSPECTION WILL BE CARRIED OUT BY NUSTEC.
8. [Announcement of Symposia and Meetings]
9. [Editorial Note]
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1. [Overview] by Shoji NAGAMIYA
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ACCELERATOR IMPROVEMENT IN PROGRESS
During the fall run significant progress has been observed
in the accelerator performance. First, the extraction efficiency
for slow spill beams
to the hadron hall reached 99.5 %. Namely, only 0.5 % loss is
observed at the extraction point. This was due to fine tuning of
a dump magnet. This high extraction efficiency is very close to the
theoretical limit, since the original calculation showed that this
number would be the maximum limit. Note that the extraction
efficiency for the slow beam at KEK-PS was 90 %.
Second, the beam power for the 3 GeV went up to 200 kW and that for
the 50 GeV to 115 kW. The accelerator people are ready for 300 kW,
but we will run at this level for a while, because we would like to
see stability for the neutron source for a while.
BUDGET WAS ANNOUNCED AT THE END OF 2010
The next-year budget was announced from our funding agency at
the end of December, being subject to the approval of Diet, though.
For JAEA an 8 cycle operation was approved (9 cycles, which is 200
days, is our ultimate goal). Also, the 400 MeV upgrade and a
neutron beamline were approved and they are in the budget.
In addition, a budget associated with a new third party operation
was approved. Furthermore, an improvement of the Linac and 3 GeV
toward 1 MW operation was approved under the new frontier special
budget framework. For KEK a 6 cycle operation was approved.
Altogether, 115 Oku Yen was approved for JAEA and 66 Oku Yen was
approved for KEK. In addition, out of the 2010 Supplemental Budget,
5.4 Oku Yen was approved at KEK for construction of the ultra slow
muon channel and 2.8 Oku Yen was approved at JAEA for construction
of a neutron beam line. Furthermore, 7 Oku Yen is reserved for a
new third party operation. Overall our budget status is reasonably
good.
EXPERIMENTAL PROPOSALS WERE IN DUE
December 7 was the deadline for submission of new MLF proposals
and December 6 was the deadline for submission of new Particle and
Nuclear Physics proposals. The PAC for Particle and Nuclear Physics
will be held on January 14-16, 2011.
MAYOR OF TOKAI VILLAGE VISITED ISIS AND CERN
In October of 2010, the Mayor of Tokai Village, Tatsuya Murakami,
visited ISIS and CERN to study and learn how these two places are
handling foreign visitors. The delegation of about 10 people
received enthusiastic receptions at both places. The Village
announced after the trip to take care of more things for foreign
visitors at J-PARC.
CONSTRUCTION OF ACCESS ROAD TO J-PARC INITIATED
In December of 2010, the new budget initiative for construction
of a special road directly to the J-PARC site was approved in Tokai
Village. We anticipate the completion of this new road at the end
of FY2011. If this road is in place, then users can come directly
to the J-PARC campus without going through the main JAEA gate.
We are discussing how to create a new gate to the J-PARC.
NEW DORMITORY WILL BE OPEN ON JANUARY 17TH
On January 17 a new dormitory with 49 rooms will be open for
users. The place is near the area of Ibaraki Quantum Beam
Research Center. Details will be given at Users Office, or,
some place in this Newsletter. In addition, a new cafe was
already open in the 2nd floor of Ibaraki Quantum Research Beam
Center and also near the MLF Experimental Facility.
A-TAC AND IAC AND OTHER COMMITTEES TO BE HELD
On February 17-19 our annual Accelerator Technical Advisory
Committee (A-TAC) will be held, followed by our annual International
Advisory Committee (IAC) on February 21 and 22. In addition, the
annual Muon Science Advisory Committee (MuSAC) and the annual
Neutron International Advisory Committee (NIAC) will be held on
February on 18-19 and February 28 to March 2, respectively.
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2. [Accelerator Division] by Ainosuke ANDO
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THE SCHEDULED MAINTENANCE AND IMPROVEMENTS WERE SUCCESSFULLY FINISHED
1. MR (Main Ring / 50-GeV Synchrotron)
(1) As mentioned in the previous newsletter, MR is now ready for
the 8-bunch operation without problems of beam-heating up to the beam
power of 750 kW.
(2) The collimator in 3-50BT ; Beam Transfer line from RCS
(3-GeV synchrotron) to the MR, has been improved to permit a 2-kW beam
loss, which makes active forming of the beam shape possible.
This will give us an advantage to understand and to reduce beam
losses in the MR.
2. RCS (3 GeV Synchrotron / Rapid Cycling Synchrotron)
(1) Many different types of charge exchange foils have been
mounted to obtain an optimum thickness and shape from the viewpoint
of the minimum beam loss in the accumulation stage where the loss is
dominated by large angle Rutherford scattering due to multi-passage
of the foil.
(2) The chromaticity correction will be done during the full
acceleration period by AC power supplies for sextupole magnets. This
would contribute to the reduction of beam loss at dispersive points
in the acceleration.
3. MPS (Machine Protection System)
There are concurrent beam supplies from RCS to MLF (Materials
and Life science Facility) and MR. Previously when an MPS
interlock in one side activated, the supplies to both sides were
interrupted for maximum protection. After operational experience,
this system has been updated so as to suspend only the corresponding
supply to the source facility of an interlock.
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3. [Nuclear and Particle Physics Division]
by J.IMAZATO, S.SAWADA, M.IEIRI and K.H.TANAKA and T.TSUKAMOTO
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NEW BEAMLINE K1.1BR WAS COMMISSIONED (by Jun IMAZATO)
A low-momentum separated-kaon beam line, K1.1BR, which was
completed this summer, has been commissioned in this October
successfully. The TREK group, intending to use its beam for their
stopped K+ experiments, performed kaon beam survey and tuning.
Thanks to a Fitch type Cherenkov counter with high performance, the
kaon beam could be tuned efficiently under the electro-static
separator (ESS) operation up to +-300 kV.
For the standard slit openings used for experiments, a K+ beam
could be observed with nearly the expected intensity. Thanks to the
beam optics employed for K1.1BR named "intermediate imaging", a
fairly good K/pi ratio of about 1 could be confirmed even for the
single stage separation by ESS. An exactly round beam spot with the
diameter of 1.1 cm (in sigma) was formed at the experimental target
point. After the beam tuning, the kaon beam was delivered to a test
experiment of a liquid argon detector prototype. For a while, this
beam line will be used as a test beam for detector development.
OCT. AND NOV. RUN FOR SLOW EXTRACTION SUMMARY
(by S.SAWADA, M.IEIRI and K.H.TANAKA)
Autumn Slow Extraction run of 50-GeV PS started on October 12th
and ended on November 16th. Total beam time used for experiments was
approximately 400 hours. Beam time used by each experimental team
was summarized below.
Beam Line Exp. Beam Time(hr)
K1.8 E19 258
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K1.8BR E17 119
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KL E14 384
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K1.1BR T25 12
E06 128
T32 147
E06 30
T38 55
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Especially E19(Search for Penta Quark, Theta+, via the
p(pi-,K-)X Reaction) used the beam as the FIRST official
"Experimental Beam Time". Thanks to the stable slow extraction
beam operation by the 50-GeV PS crew members, i.e. less than 10%
down time, each experimental team enjoyed the beam and performed
the experiments successfully.
T2K ACCUMULATED MORE DATA AFTER SUMMER SHUTDOWN (by T.TSUKAMOTO)
Many works on the T2K neutrino beam line facility and T2K near
detector ND280 have been done during this summer shutdown. In
addition to work for maintenance such as a test for remote
maintenance of target station equipments, work to install many
new equipments such as a new horn power supply were carried out.
Neutrino beam operation started from the middle of November.
Delivered proton beam intensity was started from about 75kW and was
increased to about 115kW. Accumulated data is about 4.2 e+19 POT
(Protons On Target) after this summer shutdown and 7.6 e+19 POT in
total. Analysis of data accumulated by this summer corresponding to
3.23e+19 is being carried out and a status report was presented at
the T2K collaboration meeting held on December 9-11.
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4. [Materials and Life Science Division] by Masatoshi ARAI
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200 KW OPERATION FOR THE 2010B PERIOD HAS STARTED
1. Neutron Source
The MLF operation was resumed on Oct. 15, 2010. Normal operation
of the new accumulator, which was replaced in the summer maintenance
period, was confirmed, so that the functionality to suppress a
pressure fluctuation of the cryogenic hydrogen circulation system was
recovered. The operation from October through December was halted
twice due to heat exchange degradation in the cryogenic hydrogen
system. Contamination of impurities (possibly water vapour) in
helium gas is a possible reason, and elimination of the impurities
is on going for the next operation cycle in January.
Proton beam power of MLF was stepped up from 120 kW to 200 kW
in December. We have not seen any relevant problems in the target,
moderator, shielding and instrument systems during a short trial
period, and we decided on a continuous operation with this power
until the next major power-up scheduled for next fall.
The beam optics of the proton beam transport line was determined
when a couple of octupole electromagnets would be introduced. The
beam current density onto the mercury target is expected to be
reduced with flatter proton beam profile. The specifications of the
octupole electromagnets were also finalized for procurement.
The designs of a target vessel with bubblers and a gas supply
system to the bubblers to mitigate pressure waves are ongoing to
fabricate and install in the 2011 summer shutdown period. The
prediction code of accumulated gas at each component in mercury
circulation loop is being developed to control the supplied gas to
the bubblers through experimental data obtained in mercury and water
loops.
CONSTRUCTION OF SIX NEW INSTRUMENTS IS CONTINUING
2. Neutron Science
After the power-up from 120kW to 200kW in December, significant
improvement in data quality has been observed in many instruments.
Diffractometers can perform quick experiments, and statistics in
inelastic scattering data have been obviously much advanced. Now
we can foresee great output from MLF in 2011.
User operation for the 2010B period (from December 2010 to
March 2011) has started and 54 accepted general proposals called by
J-PARC as well as 31 general proposals called by Ibaraki prefecture
(proposals from industrial users to two Ibaraki prefecture beamlines)
are being carried out. The call for next term proposals (2011A) was
closed and 130 general proposals were submitted. The submitted
proposals will be reviewed by the neutron science proposal review
committee, and results of each proposal will be informed to
applicants by the end of the fiscal year.
A vacuum tank of TAIKAN (BL15, Small Angle Scattering
Instrument) was installed on Dec. 23rd. An annex building for
SPICA (BL09, Special Environment Powder Diffractometer) is under
construction. For PLANET (BL11, High Pressure Diffractometer),
choppers, supermirror guide tubes and all the shielding were
installed already. Beamline shielding for DNA (BL02, Inverted
Geometry Spectrometer) is under construction. The construction
of two other new instruments, VNR (BL17, Vertical Reflectometer)
and SENJU (BL18, Single Crystal Diffractometer), is also continuing.
"FLY PASS SYSTEM" WAS NEWLY INTRODUCED TO MUSE FOR THE MuSR
MEASUREMENTS WITH A TINY VOLUME
3. Muon Science
At the MUSE Decay-Surface Muon (D1) area, a surface muon beam
has been delivered with a beam size larger than 40mm in diameter.
Therefore, we are having a serious problem on S/N ratio in the
muSR measurements, in particular for small specimens of less than
40mm in diameter, because of background due to muons not stopped
in the sample.
In order to overcome this problem, we have installed so called,
"Fly Pass System" which is an extension of the muon beam duct even
downstream of the sample specimen. Muons not stopped at the sample
specimen are designed to pass away in the extended duct to further
distance. Therefore, the S/N ratio even with use of a 5x5mm^2
specimen was discovered to become better than 1/1. This development
will enable us to perform muSR experiments at MUSE with a tiny
volume such as a precious single crystal, etc.
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5. [Exotic Nuclear Science Group] by Hiroari MIYATAKE
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THE FIRST OBSERVATION OF LASER RESONANCE IONIZATION OF IRIDIUM ATOMS
The laser resonance ionization of iridium atoms was successfully
achieved for the first time in collaboration with RIKEN SLOWRI group.
The wavelengths of the first and the second laser pulses were found.
The ionization scheme will be used for the lifetime measurements of
neutron-rich isotopes by KEK isotope separation system (KISS).
The laser resonance schemes for other elements will be searched for.
POLARIZED RADIOACTIVE INDIUM BEAM PRODUCED BY TILTED FOILS
The radioactive nuclear beam of In-123 was successfully
polarized by applying the tilted foil technique in collaboration
with the Osaka Univ. group. The radioactive isotopes of In-123 were
produced by fission reactions of uranium with proton
beams from the tandem accelerator at Japan Atomic Energy Agency
(JAEA). They were ionized by JAEA Isotope Separator On-Line (ISOL),
converted to multi-charged ions by the charge breeder and accelerated
up to the energy of 305 keV/nucleon by two linear accelerators at
Tokai Radioactive Ion Accelerator Complex (TRIAC). Penetrating 20
thin carbon foils, the accelerated beam was polarized to about 1%
degree of polarization.
THE REACTION CROSS SECTIONS OF 12C(ALPHA,GAMMA)16O WERE MEASURED
FOR ASTROPHYSICAL INTEREST
The reaction cross sections of 12C(alpha,gamma)16O were measured
at three different energies, 1.12MeV/nucleon, 0.77 MeV/nucleon and
0.70 MeV/nucleon in collaboration with JAEA group. Gamma-ray angular
distribution measurements solve the interference pattern of E1 and
E2 components of gamma transitions, which are considered to affect
the heavy element synthesis at 300 keV stellar temperature.
In order to improve the signal-to-noise ratio of measurements,
the 2 MHz pulsed alpha beam was developed at TRIAC by newly importing
a chopper and a pre-buncher. Typical beam intensity on the
water-cooled 12C target was about 5 micro A.
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6. [Nuclear Transmutation Section] by Hirofumi TSUJIMOTO
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DEVELOPED THE ULTRASONIC DOPPLER METHOD FOR FLOW
MEASUREMENT OF LIQUID METAL
In the Accelerator Driven System (ADS), which has been developed
in JAEA, liquid Lead Bismuth Eutectic (LBE) alloy would be used for
a coolant and a spallation neutron target. To estimate the
thermo- fluid behavior of the LBE coolant and the spallation target
in ADS accurately, verification of the CFD (computational fluid
dynamics) analysis is important. However, the measurement of liquid
metal flow is difficult because of its opaque nature.
To acquire the velocity information in the flowing LBE, the
measurement technique by using ultrasonic Doppler method has been
developed in JAEA. This technique was applied to an actual LBE flow
(150 degrees C) in an LBE target model to measure the
three-dimensional flow structure near the beam window. The measured
results showed that the flow structure was not symmetric for the
direction of gravity, and the symmetrical structure for the horizontal
direction was collapsed with increasing of the flow rate, more than
30 l/min.
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7. [Safety Division] by Taichi MIURA and Hiroshi NAKASHIMA
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THE 10TH RADIATION SAFETY COMMITTEE OF J-PARC MET ON DEC. AND THE
PERIODICAL INSPECTION WILL BE CARRIED OUT BY NUSTEC
The 10th Radiation Safety Committee of J-PARC met on Dec. 7, 2010
and discussed the alterative application of all J-PARC facilities.
The main topics are the abolition of the injection dump in the 50GeV
proton synchrotron, the power-up and the shielding reinforcement for
a primary beam line including beam dump for the Hadron Facility,
the new secondary beam lines in Materials and Life Science Facility.
These applications were submitted to the Ministry of Education,
Culture, Sports, Science and Technology (MEXT) on Dec. 15.
As five-years of radiation handling is approaching in J-PARC,
the first periodical inspection will be carried out by the Nuclear
Safety Technology Center (NUSTEC) in Jan. 2011, to make sure that
radiation installations are maintained in compliance with technical
standards by the Radiation Hazards Prevention Law.
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7. [Announcement of Symposia and Meetings]
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1) 2nd MLF Symposium, Jan. 17-18, 2011 at KEK, Tsukuba (Language:
Japanese) http://j-parc.jp/MatLife/ja/meetings/MLFsympo/index.html
2) The International Workshop on Neutron Applications on Strongly
Correlated Electron Systems 2011 (NASCES11), Feb. 23-25, 2011 at
Ibaraki Quantum Beam Research Center, Tokai (Language: English)
http://j-parc.jp/MatLife/en/meetings/NASCES/index.html
3) Workshop on High Magnetic Field & High-Pressure Environments for
Neutron Scattering Experiments at MLF/J-PARC, Mar. 8-9, 2011 at
Ibaraki Quantum Beam Research Center, Tokai (Language: Japanese)
http://j-parc.jp/MatLife/ja/meetings/extreme/
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8. [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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