======================================================================
J-PARC Project Newsletter
No. 48, Apr. 2012
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
======================================================================
HEADLINES AND CONTENTS
1. [Overview]
J-PARC IS RUNNING WELL.
J-PARC REVIEW IN PROGRESS.
INTERNATIONAL ADVISORY COMMITTEE AND OTHER COMMITTEE MEETINGS WERE
HELD.
RISE IN ELECTRICITY POWER COST ANNOUNCED BY TEPCO.
2. [Accelerator Division]
STATUS OF THE ACCELERATOR FACILITIES: USER SERVICE WAS STARTED.
A-TAC (ACCELERATOR ADVISORY COMMITTEE) MEETING.
3. [Nuclear and Particle Physics Division]
SLOW EXTRACTION RESUMES AFTER EARTHQUAKE.
T2K STATUS: STABLE DATA TAKING RESTARTED AFTER 1 YEAR OF RECOVERY
FROM THE EARTHQUAKE.
4. [Materials and Life Science Division]
RESUMING USER OPERATION.
EIGHTEEN NEUTRON INSTRUMENTS INCLUDING SIX NEW ONES HAVE BEEN STARTED.
COMMISSIONING OF NEW DETECTORS.
THE REGULAR USERS' PROGRAM AT MUSE WERE RESTARTED FROM FEB. 2ND,
2012.
5. [Exotic Nuclear Science Group]
SELECTIVELY IONIZED ATOMS EXTRACTED AT KISS.
CROSS SECTION MEASUREMENTS WERE PERFORMED FOR MULTI-NUCLEON TRANSFER
REACTIONS.
6. [Nuclear Transmutation Section]
INTERNATIONAL SYMPOSIUM ON FUTURE OF ACCELERATOR DRIVEN SYSTEM WAS
ORGANIZED.
7. [Safety Division]
THE SAFETY INSPECTIONS OF MLF AND HD WERE SUCCESSFULLY CONDUCTED BY
NUSTEC.
8. [Announcement of Symposia and Meetings]
9. [Editorial Note]
----------------------------------------------------------------------
1. [Overview] by Shoji NAGAMIYA
----------------------------------------------------------------------
J-PARC IS RUNNNING WELL
A new fiscal year started on April 1st.
After the recovery from the damage due to the earthquake, the
J-PARC has been running reasonably well. In January we had troubles
in the power supply for the neutrino horn (horn = focusing device to
narrow down the pion beam toward Super-Kamiokande). At the end of
March we had another trouble in the power supply for klystrons at an
early stage of Linac and this trouble created shutdown of the entire
beams for over a week. It was recovered by swithcing a power supply.
Otherwise, we had a smooth running for user operation. Both
neutron and muon took data. Hadron also took data while the neutrino
program was off. In addition, the neutrino group started to take
data from March and they added statistics.
In JFY2012 we plan to run user programs up to about 180 days.
J-PARC REVIEW IN PROGRESS
The Government started their review of J-PARC on March 7, 2012.
At the first meeting, the status of the J-PARC was reported. Also,
many discussions were held on how to proceed with reviews of the
entire project.
In April there are two review meetings. Here, 1) the
organization for the J-PARC operation, 2) internationalization, and
3) future scope of all facilities will be reviewed. A particular
emphasis is the point 3). The review of materials and life science
is planned at the first meeting and other reviews on accelerator,
hadron, neutrino, and nuclear transmutation will be held at the
second meeting in April. In May, two meetings are also planned.
At the first meeting in May, all future plans will be discussed and
prioritized. At the second meeting in May the writing of the
recommendations will be discussed.
The chair of the review committee is Professor Hide Fukuyama.
INTERNATIONAL ADVISORY COMMITTEE AND OTHER COMMITTEE MEETINGS WERE
HELD
The International Advisory Committee (Chair: Jean-Michel
Poutissou) was held on February 27 and 28. Prior to this meeting,
Neutron Advisory Committee (Chair: Uschi Steigenberger) and Muon
Advisory Committee (Chair: Elvezio Morenzon) were held in early to
middle of February. All committees discussed seriously the present
performance as well as future prospects of J-PARC. Reports are
being prepared.
Also, on March 16-18 the Particle and Nuclear Physics PAC was
held. The discussion at this time focused on the future five year
plan in both particle physics and nuclear physics. Results will be
presented at the Review Committee by the Government.
RISE IN ELECTRICITY POWER COST ANNOUNCED BY TEPCO
The TEPCO announced a large (about 30%) increase for J-PARC
electricity bill from JFY2014. We are very disappointed with it and
will have a negotiation with TEPCO and the Government.
----------------------------------------------------------------------
2. [Accelerator Division] by Kazuo HASEGAWA
----------------------------------------------------------------------
STATUS OF THE ACCELERATOR FACILITIES: USER SERVICE WAS STARTED
In December 2011, operations were low duty such as single-shots
or 1 to 2.5 Hz for beam tuning at the linac, the 3 GeV rapid cycling
synchrotron (RCS), the Materials and Life Science Experimental
Facility (MLF), the Main Ring (MR) and the Neutrino Experimental
Facility (NU).
At the beginning of January 2012, we started beam tuning at the
full repetition rate of 25 Hz at the linac and the RCS. During the
tuning, we performed the 300 kW test from the RCS and confirmed that
we could increase the power when the neutron target would be ready.
After the tuning, the user program of the MLF and the NU started at
120kW and 60 to 87 kW, respectively.
In February, since a power supply for the electromagnetic horn
at the NU broke down, the beam from the MR was tuned and delivered to
the Hadron Experimental Facility (HD). As a result of the tuning,
beam power of 10 kW was attained in the demonstration, and beam of
3.3 kW with duty factor of 30 % was delivered to the hadron users
successfully.
At the start-up after the maintenance period in February, the
beam current from the linac was increased from 15 to 20 mA and a 420
kW tuning with the RCS was carried out. This condition was also
performed in January 2011, and the impact of misalignment of the RCS
magnets due to the earthquake was examined. As a result, by adjusting
the operating parameters of the RCS, we can reduce beam loss in the
RCS and in the downstream beam transport line. The beam loss is still
higher than that before the earthquake, but the amount is at an
acceptable level.
Therefore, we decided to perform realignment of the RCS magnets,
which will take several months, in the summer of 2013 according to
the shutdown for an energy upgrade of the linac.
The beam to the NU was delivered at 140 to 150 kW in March. By
shortening the cycle time from 2.8 to 2.6 seconds, the beam power
was increased to 170 to 180 kW. In addition, 200 kW user operation to
the MLF was started by increasing pulse length on March 15.
The J-PARC accelerator facilities have been operating
successfully until March 22, however, operation stopped at 4:10 am
by the trouble of the linac klystron power supply. The cause was due
to the diode breakdown in the high voltage transformation unit.
Finally, we replaced the transformation unit and the user operation
to the MLF and the NU was resumed on April 8. Because the user
program was stopped by this trouble for more than two weeks, the
operation schedule in the 2012 fiscal year was modified to reduce
this influence.
A-TAC (ACCELERATOR ADVISORY COMMITTEE) MEETING
The 11th A-TAC (Accelerator Technical Advisory Committee) was
held at Ibaraki Quantum Beam Research Center on February 23 to 25.
Eight committee members attended and about 20 reports were presented
such as the recovery from the earthquake, current situation,
performance upgrade, etc. The committee deliberated and argued about
the improvement points, future directivity, etc., and advice and
recommendations were received from the committee.
----------------------------------------------------------------------
3. [Nuclear and Particle Physics Division] by M. NARUKI & T.TSUKAMOTO
----------------------------------------------------------------------
SLOW EXTRACTION RESUMES AFTER EARTHQUAKE (by M. NARUKI)
The slow extraction resumed at the end of January 2012 after the
recovery work. The primary beam has been successfully extracted to
the Hadron Hall and transported into the beam dump. The typical beam
power was 3.3kW. The new Pt production target with the indirect water-
cooling system was successfully operated to find that it coped with
the beam intensity of 30kW.
The secondary particles were delivered to the K1.8, K1.8BR and KL
beam lines. The E19 experiment searched for the Theta+ pentaquark in
the p(pi-,K-)X reaction with the maximum momentum of 2 GeV/c at K1.8.
They accumulated the beam pions of 8.7x10^10 to reach the sensitivity
of 0.3 micro-barn/sr. All the detector components worked well, and
especially the beam tracking devices were able to operate stably
under the typical intensity of 1.7M/spill with improved duty factor
of 18%.
At the K1.8BR area, beam tuning of 1.0 GeV/c for the E15
experiment (kaonic-nuclei search) was successfully completed; the
obtained yield of 1.0 GeV/c K- was 10k/spill/1kW with good K/pi
ratio of 0.4. In addition, the commissioning of the cylindrical
detector system (CDS) was conducted with a liquid-4He target in order
to study the background to the kaonic-nuclei search. Target images
and invariant mass of Lambda -> ppi- have been successfully
reconstructed by the CDS in the preliminary results.
The KOTO group performed a detector study to establish the
calibration method for the electromagnetic calorimeter at the KL
beam line. They successfully accumulated the events of neutral
kaons decaying into charged pion, electron, neutrino and into
three neutral pions. The next beam time for the Hadron Hall is
expected in June.
T2K STATUS: STABLE DATA TAKING RESTARTED AFTER 1 YEAR OF RECOVERY
FROM THE EARTHQUAKE (by T.TSUKAMOTO)
As reported in the previous issue of J-PARC newsletter, a
serious trouble in the horn power supply arose on December 22
during final operation test. Switching devices called IGBTs in the
horn power supply were broken.
Since it turned out that it takes a few months to get new IGBTs,
we decided to use the old horn power supply which had been used until
June, 2010 and was moved to KEK Tsukuba campus. Everything was
finished in time for the beam but unfortunately a trouble of
thyristor arose. We lowered the horn operation current from 250kA to
200kA for safety until we will investigate the cause and fix it.
We are also working to repair the new power supply. Detailed checks
for repair are being performed.
We confirmed with use of beams that the alignment of magnets etc.
in the neutrino beam line is OK, which were re-aligned after the
earthquake. Beam tuning was carried out and the beam power reached
150kW which is almost the same as before the earthquake.
The commissioning of the neutrino beam has been successfully
carried out and the T2K experiment has started normal data
acquisition and collected data for the delivered POT (proton on
target) is 2.19 x 10^19 in this beam run #41 (by the end of March).
----------------------------------------------------------------------
4. [Materials and Life Science Division] by Masatoshi ARAI
----------------------------------------------------------------------
RESUMING USER OPERATION
1. Neutron Source
The conventional facilities resumed for beam operation without
any serious problems. The first proton beam pulse was successfully
transported from the RCS to the MLF target with an initial magnet
setting. Then the beam line was tuned and optimized to the operation
for user programs. The beam power was started with 100 kW and raised
to 200 kW to recover the previous power right before the disaster in
the middle of March.
A helium gas purification unit was newly installed to the
cryogenic hydrogen system in order to drastically reduce a problem
from adsorbed moisture caused in 2011 in parallel with restoration
work. This upgrading solved an impurity issue of the system, and
made the system operation in this winter much more stable.
The surface roughness of the PIE (Post Irradiation Examination)
specimens cut out from the first target was measured and the maximum
pit depth of ca. 250 micro meter was found, which will be the
important data to estimate the target vessel lifetime. The 2nd target
vessel has been working without any troubles.
EIGHTEEN NEUTRON INSTRUMENTS INCLUDING SIX NEW ONES HAVE BEEN
STARTED
2. Neutron Science
Eighteen neutron instruments were successfully started. Six new
instruments are DNA (BL02, Inverted Geometry Spectrometer), SPICA
(BL09, Powder), PLANET (BL11, High Pressure Diffractometer), TAIKAN
(BL15, Small Angle Neutron Scattering), SHARAKU (BL17, Vertical
Reflectometer) and SENJU (BL18, Single Crystal Diffractometer).
For the user operation of the 2012A period (April to November,
2012), 127 general neutron proposals have been submitted; after
evaluation by four referees for each proposal followed by the review
in the neutron science proposal review committee (NSPRC) held on March
1st, 100 proposals were approved and 18 were reserved. The results
were approved by the MLF advisory board on March 13th.
QENS2012/WINS2012
Nikko Joint Conference between 10th International Conference
on Quasielastic Neutron Scattering (QENS 2012) & 5th Workshop on
Inelastic Neutron Spectrometer (WINS2012) will be held in Nikko
Public Meeting Hall from 30th Sep. to 4th Oct. which is hosted by
J-PARC Center with achair of Masatoshi Arai, MLF Division Leader.
http://j-parc.jp/researcher/MatLife/en/meetings/QENS-WINS2012/index.html
COMMISSIONING OF NEW DETECTORS
3. Neutron Instrument
New types of a two-dimensional large area scintillator detector
and a two-dimensional multi-wire proportional chamber with individual
readout system have been successfully developed for BL18, SENJU, and
BL17, SHARAKU.
The scintillator detectors with 33 modules were made based on
the scintillator/wavelength shifting fiber technology. These were
delivered to the beamlines by the end of March and the detector
commissioning is currently underway.
THE REGULAR USERS' PROGRAM AT MUSE WERE RESTARTED FROM FEB. 2ND, 2012
4. Muon Science Facility (MUSE)
We managed to recover from all the damage induced by the
earthquake on March 11th, 2011 by the end of December, 2011.
It is our great pleasure to report we could deliver again,
surface & decay muons up to 60 MeV/c beam towards D1 and D2 in the
commissioning beam time held at Jan. 17th, 2012. The regular users of
experiments were also restarted from Feb. 2nd.
During a period of fixing, we installed a kicker magnet
associated with a septum magnet to allow a single bunched muon beam
cut out from the two bunched structure up to 60 MeV/c towards D1 and
D2 areas in the MUSE secondary Decay-Surface Muon Beamline (D-line).
It worked well, but it turned out we need further R&D in order to
reduce noise signals that appeared in the Muon Spin Rotation,
Relaxation and Resonance (muSR) spectrum.
----------------------------------------------------------------------
5. [Exotic Nuclear Science Group] by Y. HIRAHARA and Y.X. WATANABE
----------------------------------------------------------------------
SELECTIVELY IONIZED ATOMS EXTRACTED AT KISS (by Y. HIRAYAMA)
We have been constructing the KEK Isotope Separation System
(KISS) at RIKEN to study unexplored neutron-rich isotopes with
neutron number N=126 for astrophysical interest. Using the KISS,
isotopes of interest are produced by nuclear reactions and collected
in a gas-cell filled with the argon gas. At the exit of the gas-cell,
isotopes as neutral atoms are ionized by applying the laser resonant
ionization technique. The selectively ionized atoms are then mass-
separated.
As an offline test, neutral atoms of nickel evaporated from a
filament inside the gas-cell were selectively ionized and extracted
as nickel ion-beams at the KISS.
CROSS SECTION MEASUREMENTS WERE PERFORMED FOR MULTI-NUCLEON TRANSFER
REACTIONS (by Y.X. WATANABE)
Neutron-rich nuclei around neutron number of 126, which are
expected to be difficult for production by the uranium fission, will
be synthesized as TLF's (target-like fragments) of multi-nucleon
transfer reactions between a Pt-198 target and a Xe-136 beam of
around 8 MeV/nucleon at the KISS project.
In order to estimate the yields, we have performed an experiment
at GANIL (Grand Accelerateur National d'Ions Lourds) to measure the
cross-sections of PLF's (projectile-like fragments) produced by the
reactions.
The PLF's were clearly separated and collected by the VAMOS
(variable mode high acceptance spectrometer), and gamma-rays emitted
from TLF's as well as PLF's were simultaneously detected. Detailed
analysis is in progress.
----------------------------------------------------------------------
6. [Nuclear Transmutation Section] by Hiroyuki OIGAWA
----------------------------------------------------------------------
INTERNATIONAL SYMPOSIUM ON FUTURE OF ACCELERATOR DRIVEN SYSTEM WAS
ORGANIZED
The International Symposium on Future of Accelerator Driven
System (ADS) was held on Feb. 29th, 2012 at Gakushi-kaikan, Tokyo,
hosted by J-PARC Center and Nuclear Science and Engineering
Directorate of JAEA. The objectives of this symposium are to discuss
the role of ADS in the future nuclear utilization and to make
participants acquainted with the current status and future plans for
research and development of ADS in the world. There were about 100
participants. At the beginning of the symposium, Dr. Arima, former
Minister of Education, provided a special talk about the expectation
for transmutation technology. In the general sessions, current
activities and future plans for R&D of ADS were presented from Japan,
China, Korea, India, and Belgium. There were presentations for
future plans of nuclear utilization and the role of partitioning and
transmutation in Japan and Europe. After these presentations, a panel
discussion was organized with regard to the prospective international
collaboration and multidisciplinary synergy effect. Through the
discussion, common understanding was promoted concerning the
importance of international collaboration and appropriate sharing.
----------------------------------------------------------------------
7. [Safety Division] by Taichi MIURA and Hiroshi NAKASHIMA
----------------------------------------------------------------------
THE SAFETY INSPECTIONS OF MLF AND HD WERE SUCCESSFULLY CONDUCTED BY
NUSTEC
The inspection of the Materials and Life Science Experimental
Facility (MLF) was conducted successfully on Feb. 6,7 by the Nuclear
Safety Technology Center (NUSTEC): the inspection items were working
conditions of emergency and interlock signals from the new secondary
beam lines and shielding structures and measurements of ambient
doses around the radiation control areas.
The inspection of the Hadron Experimental Facility (HD) was
conducted successfully on Feb. 21, 2012, by the NUSTEC: the
inspection items were shielding structures and measurements of
ambient doses around the radiation control areas.
----------------------------------------------------------------------
8. [Announcement of Symposia and Meetings]
----------------------------------------------------------------------
1) Nikko Joint Conference between 10th International Conference on
Quasielastic Neutron Scattering (QENS 2012) & 5th Workshop on
Inelastic Neutron Spectrometers (WINS 2012), Sep. 30th - Oct. 4th,
2012, Nikko, Japan (Language: English)
http://j-parc.jp/researcher/MatLife/en/meetings/QENS-WINS2012/index.html
----------------------------------------------------------------------
9. [Editorial Note]
----------------------------------------------------------------------
In case you do not wish to receive this Newsletter in the
future, please send an email to news-l-ctl@ml.j-parc.jp
and simply write one sentence in the body of the message as
unsubscribe
If you wish to receive, write one sentence in the body of the
message as
subscribe
You can get a help with a sentence of "help" in the body.
Information on the project can be also obtained at the Web site:
http://j-parc.jp/index-e.html
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto@kek.jp
Nobuaki TAKAHASHI: nobuaki.takahashi@jaea.go.jp
Takashi ITO: itou.takashi@jaea.go.jp
Dick MISCHKE (English Editor): mischke@triumf.ca
Toshiko MACHIDA (Secretary): machida.toshiko@jaea.go.jp
++++++++++++++++End of Letter++++++++++++++++++++++++++++++++++++++++++