[Neutron] J-PARC Newsletter No.45 Jul 2011
fujio maekawa
maekawa.fujio at jaea.go.jp
Wed Jul 27 03:21:04 CEST 2011
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J-PARC Project Newsletter
No. 45, July 2011
Japan Proton Accelerator Research Complex under operation jointly
by the High Energy Accelerator Research Organization (KEK) and
the Japan Atomic Energy Agency (JAEA)
hxxp://j-parc.jp/index-e.html
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HEADLINES AND CONTENTS
1. [Overview]
NEUTRINO GROUP OBSERVED SIX ELECTRON-NEUTRINO EVENTS.
BUDGET SEASON FOR JFY2012.
RECOVERY WORK CONTINUES WITH AN ANTICIPATED BEAM IN DECEMBER.
J-PARC KEK-JAEA STEERING COMMITTEE, THE USERS STEERING COMMITTEE, AND
J-PARC PAC WERE HELD.
ACCESS ROAD.
2. [Accelerator Division]
RECOVERY STATUS OF THE ACCELERATOR FROM THE EARTHQUAKE DISASTER
3. [Nuclear and Particle Physics Division]
EFFORTS TO RESUME EXPERIMENTS AT THE HADRON HALL.
INDICATION OF ELECTRON NEUTRINO APPEARANCE AT THE T2K EXPERIMENT AND
STATUS OF THE NEUTRINO FACILITY.
4. [Materials and Life Science Division]
RECOVERING FROM THE EARTHQUAKE DAMAGE AT JAPAN SPALLATION NEUTRON
SOURCE (JSNS) IS PROGRESSING.
RECOVERY OF MLF INSTRUMENTS IS CONTINUING.
MANY PROPOSALS WERE SENT TO SNS AND LANSCE.
DAMAGE OF MUSE WILL BE FIXED BY NOVEMBER, 2011.
5. [Nuclear Transmutation Section]
MODIFICATION AND REFRESHMENT OF JAEA LEAD-BISMUTH MATERIAL CORROSION
LOOP (JLBL-1)
6. [Safety Division]
THE 11TH RADIATION SAFETY COMMITTEE OF J-PARC WILL MEET ON JULY
7. [Information System Division]
SINET4 SUPPORTS J-PARC NETWORK CONNECTION TO THE WORLD
8. [Editorial Note]
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1. [Overview] by Shoji NAGAMIYA
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NEUTRINO GROUP OBSERVED SIX ELECTRON-NEUTRINO EVENTS
The T2K neutrino group announced that they succeeded in the
measurement of six electron neutrino events at Super Kamiokande, by
using the entire data set taken before the earthquake. This implies
that the probability of not having nu(muon) -> nu(electron) oscillation
is less than 0.7%. Also, the data suggest a large mixing angle of
theta(13). It further implies that, with higher intensity beams,
it would be possible to measure anti-neutrino oscillation to detect
CP violation in the neutrino sector. All in all, the data encourages
us enormously.
BUDGET SEASON FOR JFY2012
The budget season for the request of JFY2012 arrived. In JFY2012,
we originally planned the installation of a 400 MeV Linac. However,
the accelerator group told us that a 5-6 months shutdown would be
required for this installation. Therefore, the J-PARC Center decided
to defer this installation by one year to JFY2013. Instead, we will
request a 9 cycle operation for JFY2012, where 9 cycles means
approximately a 200-day operation for users. This proposal has been
supported by our immediate funding agency (Quantum Beam Section at
Monka-sho) as well as two organizations, KEK and JAEA, though it will
take another few months before reaching the final decision.
In addition to the above normal operational hours, we request
14.5 Oku Yen for the construction of the 400 MeV Linac (the final year
of construction) and 17 Oku Yen for the promised Linac+3GeV Upgrade.
Both proposals will be sent from JAEA. In addition, regular funding
requests from both JAEA and KEK for equipment are included in the
budget request.
RECOVERY WORK CONTINUES WITH AN ANTICIPATED BEAM IN DECEMBER
Our recovery work is in progress, with an expectation of the
first beam in December. Although some delay is observed both at the
Linac and 3 GeV, most of the recovery work for elements other than
these two is progressing smoothly. Concerning the Linac, cooling
water is the biggest issue. Pipes were disconnected at many places
around the Linac. In addition, electricity, crane, etc. still have
problems. As for the 3 GeV, the cooling tower and electricity are
now in major recovery process. This process will take a few more
months until September.
J-PARC KEK-JAEA STEERING COMMITTEE, THE USERS STEERING COMMITTEE,
AND J-PARC PAC WERE HELD
KEK-JAEA Steering Committee meeting was held to approve the
budget request. Also, the Users Steering Committee was held to
discuss budget, future development of J-PARC, results from various
experiments, etc. This implies that our life has returned to normal
after a few months since the big earthquake. Also, many visitors
gradually started to come to J-PARC to study the progress.
In the KEK Tsukuba campus the 12th J-PARC PAC meeting was held on
July 8-10.
ACCESS ROAD
The work associated with the J-PARC access road, which will be
constructed primarily by the Tokai-Mura Village, has been stopped due
to the earthquake. Now, the work resumed and both J-PARC side and
Village side started to discuss many issues associated with it.
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2. [Accelerator Division] by Kazuo HASEGAWA
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RECOVERY STATUS OF THE ACCELERATOR FROM THE EARTHQUAKE DISASTER
The accelerator steadily advances recovery efforts after the
great earthquake.
In the linac, underground water leakage to the accelerator tunnel
was an issue just after the earthquake. Work to stop leakage of
ground water was started and that of the downstream part has been
almost finished, though the upstream part continues work. The amount
of water leakage is about 2 to 3 cubic meters a day, which is
estimated to be one fifth of that just after the earthquake. The
inspection work of cranes and drilling survey of floors are underway.
The building inclines to the west generally, and a lot of gaps under
the floor were confirmed by the boring. Regular survey of the
accelerator tunnel is carried out every two weeks and movement has
been monitored. The subsidence of the straight section has settled.
Continuous evacuation of the acceleration cavities has been carried
out by ion pumps. Alignment of the first drift tube linac cavity has
been finished and followed by the downstream cavities.
In the RCS (3-GeV synchrotron), the earthwork and pavement of
the surrounding road have been completed. The work
in the yard area is on a full scale, and jack up of the transformers
and repair work of the bases have progressed. A power outage
is scheduled by the end of August for the recovery work of the yard
and equipment. Meanwhile the tunnel is dehumidified by the help of
a diesel engine power generator. Visual inspection in kicker magnets
with a fiber scope was carried out, and the magnet system was
successfully excited by 60 kV and 25 Hz of rating for a short time of
one minute. The effects of the main magnet inclination inward have
been preliminarily evaluated in a beam simulation. About 1mm of COD
(closed orbit distortion) in the vertical direction is evaluated and
this can be corrected by steering magnets. There is no significant
beam loss increase up to 300 kW, but meaningful loss is expected at
400kW.
In the MR (50-GeV synchrotron), work to stop leakage of ground
water for walls and ceilings of the tunnel is continued. This is
scheduled to be finished by the end of July, and from August we will
start alignment work of magnets. As a result of the entire
circumference survey by a laser tracker, 8 to 10 mm in vertical and
about 30 mm in horizontal displacements are revealed. When these
displacements are considered in a beam simulation, residual COD of
+/-50 mm without correction, or 20 mm with some corrections, can be
evaluated. Since these values are not small enough, we have decided
to re-align the magnets. Test operation of some high power devices
such as high frequency acceleration system, main magnets, injection
and extraction system can be successfully performed.
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3. [Nuclear and Particle Physics Division]
by J.IMAZATO and T.TSUKAMOTO
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EFFORTS TO RESUME EXPERIMENTS AT THE HADRON HALL (by J.IMAZATO)
At the moment we are doing our best to recover the beamline
functions in the Hadron Experimental Facility. As was described in
the last Special Issue, the beam lines themselves were not seriously
damaged, while a part of the Hall buildings wall has yet to wait for a
repair. Beamline elements are being measured and realigned in the
Hall as well as in the switchyard. Regarding experimental setups, we
are also making efforts to bring them back to the initial conditions.
At K1.8 the 10-cm displacement of SKS will be fixed after repairing
the three damaged feet. Fortunately, no broken detector elements were
found. The cryogenics system seems to be O.K. and it is intended to
restart cooling in October. The final confirmation of the
superconductivity soundness will be then made. It was a pity that a
few chambers were broken at the K1.8BR setup, when the magnets moved.
At the KL area the KOTO group is continuing their efforts toward the
confirmation of the beam alignments and the engineering run when the
beam is back. It turned out fortunately that all the CsI crystals
are OK in spite of the two week interruption of the dry air supply
just after March 11. In the summer the measurement and realignment
of the KL beamline is planned. We will be ready to accept a test
beam in December and start normal facility operation in early next
year as indicated in the J-PARC beam recovery master plan.
INDICATION OF ELECTRON NEUTRINO APPEARANCE AT THE T2K EXPERIMENT AND
STATUS OF THE NEUTRINO FACILITY (by T. TSUKAMOTO)
The T2K experiment collected about 2% of the original goal of
the total number of events to be collected before the great East Japan
earthquake hit on March 11, 2011. Based on this data set the T2K
experiment has detected 6 electron neutrino candidate events.
For the first time, it was possible to observe an indication that
muon neutrinos are able to transform into electron neutrinos over a
distance of 295 km through the quantum mechanical phenomena of neutrino
flavor oscillations.
The result was presented at the KEK seminar on June 15 and a press
release was issued from KEK/ICRR on the web.
hxxp://www.kek.jp/ja/news/press/2011/J-PARC_T2Kneutrino.html
hxxp://www.kek.jp/intra-e/press/2011/J-PARC_T2Kneutrino.html
The paper describing the result was submitted to Physical Review
Letters and was accepted for publication.
After J-PARC resumes producing muon neutrinos, which is planned
to happen by the end of 2011, the T2K experiment will continue
striving to accumulate the target number of events to confirm electron
neutrino appearance.
Recovery work from damages by the earthquake is continuing.
Some part of the ground surrounding buildings is severely subsided
(about 1~2m), which consequently damaged some nearby facilities and
piping/cabling, but buildings are generally fine. Temporary repair of
subsided ground was quickly performed to access buildings for recovery
work.
No damages were found by inspection in superconducting magnets
and cryogenics, and the test operation of superconducting magnet up to
operating current was successful. Test operation of normal conducting
magnets was also performed successfully except those of which some
parts will be replaced. All beam monitors were checked and found OK
except a few submerged parts. Since the tunnel was moved, realignment
of most magnets will be done.
Inspections of equipment in the Target Station (TS) are
continuing and no serious damages have been found so far. Test
operation of the horn power supply with a dummy load was done
successfully. Test operation of horns will also be done then horns
will be moved to the maintenance area for detailed visual inspection.
Inspection and test operation of sub-detectors of T2K near
detector ND280 was performed and no serious problems were found so
far. There remains some inspection and tests to check details. No
problems were found in ND280 magnet by the inspection. Test operation
of the magnet will be done with operation of the cooling water system
but we should wait for inspection and test by engineers of the German
company, which can be done in September due to constraints on visiting
Japan.
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4. [Materials and Life Science Division] by Masatoshi ARAI
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RECOVERING FROM THE EARTHQUAKE DAMAGE AT JAPAN SPALLATION NEUTRON
SOURCE (JSNS) IS PROGRESSING
1. Neutron Source
The buildings and the conventional facilities were inspected
thoroughly for any damages due to the earthquake. The restoration
work has been started all over the Materials and Life Science
Experimental Facility (MLF). The coolant facilities were overhauled
and tested. All the magnets in the proton beam transport line were
extensively surveyed and their movement caused by the quake were
recorded. The positions of the magnets have to be corrected by a
few mm. The alignment work is scheduled for this autumn.
The mercury circulation system was operated with a rated mercury
flow rate of 11.4 L/s, and the performance was confirmed to be good.
Performance of the target trolley was also tested and all functions
worked well. A seal performance test was carried out for the helium
gas supply line to the bellows seal mechanics of the mercury target,
where the possibility of helium leak was suspected, but the helium
piping was confirmed to be sound. The present mercury target vessel
will be replaced with a new one in October.
The J-PARC neutron source is equipped with three supercritical
hydrogen moderators, which have the thin fivefold coaxial tube
structure made of aluminum alloy and stainless steel. Some R&D
activities are going on to facilitate manufacturability of the
moderators. A low thermal expansion material "Invar" is to be
introduced to minimize thermal shrinkage of the moderator tubes when
they are cooled down to 20 K. Weldability and bendability of Invar
tubes have been confirmed to be workable. A combined component of
multiple tubes including a dissimilar joint of aluminum alloy and
stainless steel was fabricated successfully, which will contribute for
easier concentric alignment and definite airtightness at the joints.
RECOVERY OF MLF INSTRUMENTS IS CONTINUING.
MANY PROPOSALS WERE SENT TO SNS AND LANSCE.
2. Neutron Science
The big shake of the earthquake caused movement of many shielding
blocks of the pre-shields. The pre-shields are stacked at the
upstream position in each beamline and some of them severely moved and
leaned. At present, we are reinstalling many of pre-shields. Since
makeshift space for shielding blocks is necessary for the reinstallation,
iron plates were laid down recently in 18 m x 12 m in front of the rest
house near the MLF building. To fix subsidence of the west annex
building where BL18 (SENJU), BL19 (TAKUMI) and BL20 (iMATERIA) are
located, these instruments will be taken away from the west annex
building soon.
For the user operation of the 2011A period (April to November,
2011), 184 proposals had been submitted; they were reviewed by the
neutron science proposal review committee and approved by the MLF
advisory board. These proposals cannot be carried out until the
accelerators, MLF neutron source and instruments will be recovered from
the damage caused by the severe earthquake. However, thanks to the
decision of Spallation Neutron Source at Oak Ridge National Laboratory
(SNS) and Los Alamos Neutron Science Center (LANSCE), 24 and
5 proposals were selected and were sent to the respective facilities.
Many neutron user facilities in the world showed support to the MLF
facility and users of MLF and JRR-3. We greatly appreciate it.
DAMAGE OF MUSE WILL BE FIXED BY NOVEMBER, 2011
3. Muon Science Facility (MUSE)
The MUSE staff have been working on inspecting and fixing damage
caused by the earthquake on March 11, 2011. First of all, we have
removed a thousand tons of concrete blocks to investigate possible
leakage from the 29 pillow-seals (vacuum duct joints) installed in the
proton beam tunnel near the muon target (M2 tunnel), since the vacuum
of the M2 tunnel was found to be broken. It turned out that all the
pillow-seals have no leakage. Also we have removed all the concrete
shield blocks to investigate damage on superconducting solenoid coils,
turbines for the on-line refrigerator, and a DC separator. Fortunately,
no serious damage was found in those components in the secondary decay
muon beam line (D-line). The helium ducts, control cables, power
cables, and compressed air for the on-line refrigerator system were
damaged, due to a settlement of about 10 cm to 1.5 m outside the MLF
building. These need to be replaced from the viewpoint of the
high-pressure gas regulations. Water ducts for the air circulation
systems for the proton beam tunnels in the vicinity of the muon target
are about to be removed, since the wall where they have been attached
is about to fall down at an expansion joint between MLF and the proton
beam transport line from 3-GeV RCS (3NBT). Some concrete blocks
above the D-line ceiling were so strongly shaken that anchor bolts
for the joint were split out. Also the separation plate for air
tightness between the tunnel and experimental hall was seriously
deformed and will be replaced.
We are planning to fix all the damage by the end of November, 2011
in anticipation of the beam time planned for this December, 2011.
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5. [Nuclear Transmutation Section] by Hiroyuki OIGAWA
----------------------------------------------------------------------
MODIFICATION AND REFRESHMENT OF JAEA LEAD-BISMUTH MATERIAL CORROSION
LOOP (JLBL-1)
In JAEA, to develop LBE (Lead-Bismuth Eutectic) handling techniques
and to evaluate feasibility of structural materials in LBE, JAEA
Lead-Bismuth material corrosion Loop (JLBL-1) was made in 2001.
Until now, over 26,000 hours of operation and 7 phases of material
corrosion tests were performed. Recently, the performance of the loop
has been degraded. For instance, a decrease of the LBE flow-rate and
LBE leakage at an oxygen sensor have occurred. So some repair and
modification were required. As repair and modification of JLBL-1,
replacement and a position change of an oxygen sensor, maintenance of
EMP (Electro-Magnetic Pump) and exchange of filters were conducted.
After that, a test operation is underway. Tests for the oxygen
sensors and the oxygen concentration control system will be done in
the near future. The final goal is to perform corrosion/erosion test
under the oxygen concentration controlled condition.
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6. [Safety Division] by Taichi MIURA and Hiroshi NAKASHIMA
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THE 11TH RADIATION SAFETY COMMITTEE OF J-PARC WILL MEET ON JULY
The 11th Radiation Safety Committee of J-PARC will meet on July 29,
2011 to discuss the alternative application of J-PARC facilities.
The main topics are the new secondary beam lines including the muon
beam line in the Materials and Life Science Facility.
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7. [Information System Division] by Atsushi MANABE
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SINET4 SUPPORTS J-PARC NETWORK CONNECTION TO THE WORLD
In March 2011, the National Institute of Informatics (NII) has
upgraded SINET (Japan Science Information Network hxxp://www.sinet.ad.jp)
from version 3 to 4. Thanks to NII support of J-PARC by the
upgrading, the J-PARC network has obtained the possibility of a 10
Gbps network bandwidth both to the internet and to the Tokai-Tsukuba
interconnection that was 1 and 2 Gbps, respectively. Since in order to
realize the increased speed, the J-PARC network itself also should be
upgraded, the replacement of the J-PARC network is being planned for
the next summer (2012).
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8. [Announcement of Symposia and Meetings]
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1st Asia-Oceania Conference on Neutron Scattering,
Nov. 20-24,2011, Tsukuba, Ibaraki (Language: English)
hxxp://j-parc.jp/MatLife/en/meetings/1stAOCNS
Abstract submission deadline: Aug. 22, 2011
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9. [Editorial Note]
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+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto at kek.jp
Fujio MAEKAWA: maekawa.fujio at jaea.go.jp
Takashi ITO: itou.takashi at jaea.go.jp
Dick MISCHKE (English Editor): mischke at triumf.ca
Chikako KAIBARA (Secretary): kaibara.chikako at jaea.go.jp
++++++++++++++++End of Letter++++++++++++++++++++++++++++++++++++++++++
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