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J-PARC Project Newsletter
No. 51, January. 2013
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]
SUMMARY.
OPERATION AND FACILITY UPDATES.
BUDGET SITUATION.
PROJECT REVIEW.
FUTURE SCIENCE AT J-PARC.
AWARDS TO DR. NAGAMIYA.
J-PARC COLLOQUIUM.
2. [Accelerator Division]
BEAM OPERATION RESUMPTION AFTER THE SUMMER SHUTDOWN.
3. [Particle and Nuclear Physics Division]
THE PRODUCTION OF HYPERNUCLEI CLOSE TO THE NEUTRON DRIP-LINE IS IN
PROGRESS.
T2K STATUS: DATA TAKING RUN AFTER SUMMER SHUTDOWN.
16TH INTERNATIONAL CONFERENCE ON ELECTROMAGNETIC ISOTOPE SEPARATORS
AND TECHNIQUES RELATED TO THEIR APPLICATIONS (EMIS2012) WAS HELD.
WORKSHOP ON LOW-ENERGY RADIOACTIVE ISOTOPE BEAM (RIB) PRODUCTION BY
IN-GAS LASER IONIZATION FOR DECAY SPECTROSCOPY AT RIKEN WAS HELD.
4. [Materials and Life Science Division]
PRESSURE WAVE MITIGATION DUE TO MICRO-BUBBLES INJECTION IN MERCURY
TARGET.
STEADY 300 KW OPERATION IN PROGRESS FOR 2012B USER PROGRAM.
MLF SYMPOSIUM HELD ON OCTOBER 10 AND 11.
THE WORLD'S HIGHEST INTENSITY PULSED MUONS, 2,500,000 MUONS PER PULSE.
5. [Nuclear Transmutation Section]
TEF DESIGN: REFLECTING LESSONS LEARNED FROM THE PAST EXPERIENCES.
6. [Safety Division]
THE 14TH RADIATION SAFETY COMMITTEE OF J-PARC MET IN DECEMBER.
7. [Editorial Note]
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1. [Overview] by Yujiro IKEDA
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SUMMARY
After the 2012 summer shutdown, we safely resumed operations
with notable high-intensity and stable beams for neutron, muon and
neutrino users in October. Following them, hadron-facility users
finally received 11kW slow extracted proton beams in December.
OPERATION AND FACILITY UPDATES
In this quarterly period from October to the end of December
2012, we supplied 280 kW beams for neutron and muon user operations
at the Materials and Life Science Experimental Facility (MLF) (RCS),
200 kW for neutrino (MR/FX), and 11 kW beams for hadron (MR/SX). The
accelerator team should be acknowledged for the significantly stable
operations. One of the highlights is a successful demonstration to
mitigate pressure waves in the mercury target vessel at MLF by helium
bubble injection in the 300 kW short pulse operation. This result
clearly indicates that the MW power regime can be attained in the near
future.
BUDGET SITUATION
There has not been significant progress in the budget proposal
for JFY2013 because of the political stagnation. After the general
election in December, the new Cabinet, dominated by the Liberal
Democratic Party (LDP), was established at the very end of last
December. They asked us to propose an urgent supplementary budget
based on their economic stimulus plan. Along with that, the budget for
JFY2013 will be finalized by the end of January 2013.
PROJECT REVIEW
The review of the KEK projects was conducted by the MEXT from a
viewpoint of the large-sized facilities plan in the coming 5 years and
beyond. It will be possible to adjust the budget timeframe because of
this review.
FUTURE SCIENCE AT J-PARC
We discussed the future direction of science at J-PARC as the
"Intensity Frontier". Through this discussion, we reached the
consensus that accelerator technology would be very challenging.
AWARDS TO DR. NAGAMIYA
Shoji Nagamiya, the former J-PARC Center director, received two
honorable recognitions from Ibaraki Prefecture and Tokai Village,
respectively, for his significant achievement of the J-PARC
implementation. Especially, he was the first awardee of the award,
"Honorary Villager", from Tokai Village.
J-PARC COLLOQUIUM
The 1st J-PARC Colloquium was held on November 20, 2012. Prof.
Guido Tonelli (University of Pisa, Italy), who was the former
spokesperson of CERN's CMS collaboration, gave a lecture on the LHC
experiments looking for the Higgs bosons at CERN. The talk was
extremely interesting and gave a great insight on how they discovered
the Higgs bosons.
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2. [Accelerator Division] by Kazuo HASEGAWA
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BEAM OPERATION RESUMPTION AFTER THE SUMMER SHUTDOWN
After the summer shutdown for maintenance, a new operational
cycle (RUN #44) was started. The beam tuning of the Linac started on
September 28 followed by the tuning of the 3-GeV Synchrotron (Rapid
Cycling Synchrotron, RCS) from October 11. And then, user operation
for the Materials and Life Science Experimental Facility (MLF) and the
Neutrino Facility (NU) started as planned on October 18. The beam
power was about 210 kW for the MLF and 160 to 175 kW for the NU. These
power levels were almost same as before the summer shutdown.
We had several hours of beam trips in October (the NU experiment
was stopped by a vacuum problem in the main ring synchrotron (MR) for
about 19 hours). There was a 7 hour beam trip by a failure of a
capacitor in a radiofrequency source of the RCS, and stable operation
was performed in November. The user operation ended in the morning of
November 12.
We had an accelerator study time at the end of this RUN. To
demonstrate higher beam power operation, the extraction beam current
from the ion source was increased from 15 mA to 27 mA (at the Linac
exit). After the tuning of the Linac and the RCS, a 534 kW beam
operation was demonstrated for the MLF for 35 seconds at a 25 Hz
repetition condition. It succeeded in breaking a record of 3 GeV
output power.
In the RUN #45, the user operation of the MLF and NU was started
on November 21 as planned, and it started to the MLF at 275 kW and to
the NU at 200 kW.
Although one day shortening of user time resulted from a vacuum
trouble of the neutrino beam transportation line on December 12, the
beam use of the main ring was switched to the Hadron Experimental
Facility (HD) from the 14th as planned.
Beam power for the users was increased to 11 kW compared to 6 kW
in the previous operation in June. Beam tuning parameter survey for 15
kW operation was also performed during the machine study time.
The cycle time of the MR was changed from 2.48 seconds for the NU
to 6 seconds for the HD.
As a result, the injection beam pulse number to the main ring was
reduced and hence the injection pulse number to the MLF was increased.
The corresponding MLF beam power was increased to 290 kW and the user
operation was performed. There were no big troubles for the RUN in the
accelerators and the user operation ended in the morning of December
27 as planned.
The user hours and availabilities in the FY2012 (from April until
December) are 3,033 hours (93%) for the MLF, 2,086 hours (88%) for the
NU and 612 hours (90%) for the HD. (These availabilities include
beam trips due to troubles in the experimental facilities.)
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3. [Particle and Nuclear Physics Division]
by A. SAKAGUCHI, T. TSUKAMOTO and H. MIYATAKE
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THE PRODUCTION OF HYPERNUCLEI CLOSE TO THE NEUTRON DRIP-LINE IS IN
PROGRESS (by A. SAKAGUCHI)
The goal of E10 is the production of Lambda hypernuclei close to
the neutron drip-line by the double charge-exchange (pi-,K+) reaction
off nuclear targets. The K1.8 beam line at the Hadron Experimental
Hall is able to provide high-intensity secondary pion beams and is an
ideal beam line for the E10 experiment. Scintillating fiber and SSD
trackers were newly installed and the trigger system was upgraded to
accept the high-intensity beams. The physics data taking is now in
progress at the K1.8 beam line by using negative-pion beams of 1.2
GeV/c in momentum and 10M/spill in beam intensity.
During the Dec. and Jan. run, a 6Li target is used to produce the
neutron-rich 6(Lambda)H hypernucleus. 6(Lambda)H is a hypernucleus
made of a Lambda hyperon and a 5H nucleus. 5H has been observed as a
particle of unstable resonant state in several experiments with rare-
isotope beams. On the other hand, several theoretical calculations
predict particles of stable low lying states of the 6(Lambda)H
hypernucleus thanks to the attractive interaction between the Lambda
hyperon and nucleons in the 5H nucleus. E10 is able to give clear
conclusion on the stability of the 6(Lambda)H hypernucleus by the
missing mass spectroscopy. If 6(Lambda)H is a stable particle, it will
be the heaviest "hydrogen" we have ever synthesized.
T2K STATUS: DATA TAKING RUN AFTER SUMMER SHUTDOWN (by T.TSUKAMOTO)
Following the summer shutdown, neutrino beam operation resumed on
October 17 and continued until December 12. Originally, operation was
planned until December 14, but beam had to be stopped due to a vacuum
leak that occurred during the neutrino beam study which took place on
the evening of December 12. One of the magnets in the neutrino beam
line was inadvertently turned off and the beam hit the inside wall of
the monitor. It caused a vacuum leak.
Fortunately, the source of the leak was found to be inside of a
beam position monitor, not inside of the main ring. The leak therefore
didn't affect accelerator operation other than the neutrino beam
operation. Repair was carried out by the end of 2012 and vacuum was
restored during the end-year and new-year shutdown period, in order to
get ready for neutrino beam operation starting January 17, 2013.
The beam repetition rate of the main ring for the neutrino beam
line had been shortened to 2.48 sec in this run from 2.56 sec in the
previous run, in order to increase the power to over 200 kW. The beam
power has gradually increased with accelerator beam study and tuning.
Finally, stable operation with a beam power of 210kW was achieved.
The current T2K obtained POT (protons on target) is 6.01 x 10^19
(preliminary) in this run and 4.18 x 10^20 (preliminary) in total.
Further data analysis is ongoing and a paper covering important
details of the neutrino flux, entitled "The T2K neutrino Flux
Prediction" (http://arxiv.org/abs/1211.0469), was recently submitted
for publication to Physical Review D. The uncertainty on the ratio of
the flux predictions at Super-Kamiokande and ND280, which was below
15 % for the first T2K analysis, has been reduced to less than 2%.
16TH INTERNATIONAL CONFERENCE ON ELECTROMAGNETIC ISOTOPE SEPARATORS
AND TECHNIQUES RELATED TO THEIR APPLICATIONS (EMIS2012) WAS HELD
(by H.MIYATAKE)
EMIS2012 was held in Matsue-city, Japan from December 2 to 7,
2012 by RIKEN, KEK and IMP (China). 174 participants from 18
countries got together to discuss science and techniques relevant to
the electromagnetic experimental devices in the fields of nuclear
physics, nuclear astrophysics, nuclear chemistry, materials science,
and interdisciplinary research. The next meeting will be held in 2015
at Michigan State University (MSU), America.
WORKSHOP ON LOW-ENERGY RADIOACTIVE ISOTOPE BEAM (RIB) PRODUCTION BY
IN-GAS LASER IONIZATION FOR DECAY SPECTROSCOPY AT RIKEN WAS HELD
(by H.MIYATAKE)
The Workshop was held at RIKEN as a post meeting of the EMIS2012
conference from December 10 to 11. It was primarily motivated as an
international collaboration meeting between Japan (KEK, RIKEN) and
Belgium (KU Leuven) on the development of the IGLIS (In-Gas Laser
Ionization and Spectroscopy) method for the study of r-process nuclei.
In the meeting, the 32 participants (16 from overseas) discussed
physics cases including nuclear astrophysics and defined the technical
issues to be addressed. On the basis of this meeting, IGLIS-net, which
is a collaboration web page, has been launched to enhance
opportunities of the scientific information exchange. The web page is
managed by KEK RNB group.
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4. [Materials and Life Science Division] by Masatoshi ARAI
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PRESSURE WAVE MITIGATION DUE TO MICRO-BUBBLES INJECTION IN MERCURY
TARGET
STEADY 300 KW OPERATION IN PROGRESS FOR 2012B USER PROGRAM
1) Neutron Source
After maintenance during the summer shut-down period, the
operation of the neutron source was started in October 17, 2012.
The mitigation effect of gas micro-bubbles on the pressure waves
related with pitting damage in the mercury target vessel was studied
with various proton beam power, up to ca. 534 kW. It was confirmed
through a novel in-situ diagnostic system using a laser Doppler
vibrometer that the pressure waves were certainly attenuated with the
gas micro-bubbles. This is the first result proving the mitigation
effect by gas micro-bubbles on the running mercury target.
Continuous operation of the gas injection system was started on
November 21, enabling steady operation with a 300 kW proton beam for
the 2012B user program.
Fabrication of a spare target vessel, of which the fore part can
be separated from the rear part, was completed.
MLF SYMPOSIUM HELD ON OCTOBER 10 AND 11
2) Neutron Instruments and Science
A joint conference of the 10th International Conference on
Quasi-elastic Neutron Scattering, QENS2012, and the 5th Workshop on
Inelastic Neutron Spectrometers, WINS2012, was held in Nikko, which
is one of UNESCO's world heritages. Nikko is famous for the most
lavishly decorated shrine and the mausoleum of Tokugawa Ieyasu, who
founded of the Tokugawa shogunate at Edo. More than 100 participants
enjoyed scientific discussion and social programs. The QENS2012
topics ranged from physics to biology as well as applications,
instrumentation, theory and complementary techniques. Discussion
included recent developments of updated, newly coming or planned
inelastic and quasi-elastic neutron spectrometers, including related
issues such as developments or new ideas of data analysis software,
devices and futuristic science to be carried out on spectrometers in
WINS2012. This workshop was initiated in Japan in 2004.
The 4th MLF symposium was held in Tokyo for the first time on
October 10 and 11 at a well-known museum, the National Museum of
Emerging Science and Innovation (Miraikan). This symposium was also
jointly organized with the Ibaraki beamline workshop in order to have
participants from industries as much as possible. Over 200
participants gathered to discuss scientific results produced after the
recovery of the MLF facility from the devastating earthquake that
occurred on March 11, 2011 and enjoyed social communication among the
facility staff and users.
The 1st MLF school for novice users of neutrons and muons was
held on Dec. 18 - 21 with 24 participants who were selected from 35
applicants:15 from universities, 3 from institutes, 6 from companies.
After lectures, each participant attended one of several experimental
courses for one and a half days: inelastic scattering, reflectometry,
powder diffraction, small angle scattering, single crystal
diffraction, engineering diffraction, or muon spin rotation. They made
presentations on the last day.
The autumn course of 'the summer challenge' (URL: http://ksc.kek.
jp) for 2nd and 3rd year university students was held on November 23
and 24 using the High Resolution Powder Diffractometer Super HRPD
installed at BL08 in the MLF.
In the annual meeting of the Japanese Society of Neutron Science
(JSNS) held on Dec. 10 in Kyoto, several members related to the MLF
were awarded: Young Researcher's Award to K. Sadakane (soft matter)
and Y. Onodera (ionic conductor), Engineering Award to A. Hoshikawa,
M. Yonemura and T. Ishigaki (sample changer robot for iMATERIA), and
Y. Yasu, K. Nakayoshi and H. Sendai (DAQ middle ware).
A completion ceremony for High Pressure Neutron Diffractometer,
PLANET, was held on September 27, after an occasion of a joint
conference of the Commission on High Pressure of the International
Union of Crystallography (IUCr) and the Quantum Beam Science
Directorate of Japan Atomic Energy Agency held in Mito City on
September 23 - 27 with 95 participants (34 from outside Japan).
Another completion ceremony for the Special Environment Powder
Diffractometer SPICA dedicated for battery research installed at BL09
was held at the MLF on September 4 with over 150 participants. High-
ranked officers from the Ministry of Education, Culture, Sports,
Science and Technology (MEXT) and the Ministry of Economy, Trade and
Industry (METI) attended.
THE WORLD'S HIGHEST INTENSITY PULSED MUONS, 2,500,000 MUONS PER PULSE
3) Muon Science Facility (MUSE)
The MUSE group succeed in extracting the world's highest
intensity pulsed muons, 2,500,000 muons per pulse (proton beam
intensity of 212 kW) to the U1 experimental area. This intensity was
achieved at the U-line. It exceeds the previous records of 72,000
muons per pulse (120 kW) and 180,000 muons per pulse (300 kW), which
were achieved at the D-line in 2010. This means that the world
strongest pulsed muon intensity was achieved at the MLF.
As a next step, we are planning to stop such intense pulsed muons
towards a hot tungsten target for generating intense ultra-slow muons
in order to realize "ultraslow muon microscopes", which will promote
not only a variety of surface and nano sciences but also 3D imaging
applications.
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5. [Nuclear Transmutation Section] by Toshinobu Sasa
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TEF DESIGN: REFLECTING LESSONS LEARNED FROM THE PAST EXPERIENCES
We are continuing the revision of the construction plan for the
Transmutation Experimental Facility (TEF) for R&D of Accelerator-
driven System (ADS). Designing of the components for a liquid lead-
bismuth (Pb-Bi) spallation target is in progress.
Reflecting the experiences at the Material and Life Science
Facility, we selected a trolley-mounted type primary circuit system
for a Pb-Bi target for the ADS Target Test Facility of TEF. Two
candidates, helium gas and pressurized water, for the secondary
coolant are being compared, and we will select one of them by taking
account of the on-going cooling circuit configuration design.
A prolonged operation of JAEA Lead-Bismuth Loop #2 (JLBL-2),
which simulates an annular tube type spallation target, has been
continued without major troubles or failures at the temperature of
300 C. The loop was kept running during the year-end and new-year
period, and then total continuous running time exceeded 3,000 hours.
We expect that operation time reaches 4,500 hours in the middle of
this February. After the long-run test of JLBL-2, we will modify it to
try simultaneous measurement of Pb-Bi flow rate by Electro-magnetic
method and Ultrasonic method by collaborating with the experts of Fast
Breeder Reactor development.
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6. [Safety Division] by Taichi MIURA and Hiroshi NAKASHIMA
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THE 14TH RADIATION SAFETY COMMITTEE OF J-PARC MET IN DECEMBER
The 14th Radiation Safety Committee of J-PARC met on December 19,
2012 and discussed the alterative application of J-PARC facilities.
The main topic is the installation of the beam line in the LINAC
facility for the test of the first-stage accelerator (Radio Frequency
Quadrupole: RFQ), which is designed to allow a larger beam and will
replace the current RFQ in the accelerator tunnel.
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7. [Editorial Note]
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Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto@kek.jp
Nobuaki TAKAHASHI: nobuaki.takahashi@j-parc.jp
Takashi ITO: itou.takashi@jaea.go.jp
Dick MISCHKE (English Editor): mischke@triumf.ca
Junko BEANBLOSSOM (Secretary): beanblossom.junko@jaea.go.jp
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