J-PARC Newsletter No.32, April 2008
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HEADLINES AND CONTENTS
1. [Overview]
EXCITING NEWS FROM THE 3 GEV ACCELERATOR.
MAJOR MILESTONES IN 2008.
IAC, A-TAC and N-TAC.
THE FIRST J-PARC INTERNATIONAL SYMPOSIUM.
USERS STEERING COMMITTEE.
NEW SECTIONS IN THE J-PARC CENTER.
2. [Accelerator Division]
ONE SHOT OF 1.07E13 PROTONS WAS EXTRACTED FROM THE RCS
AT 3 GeV, WITH A MODEST BEAM LOSS, CORRESPONDING TO THE
BEAM POWER OF 130 kW, IF OPERATED AT DESIGNED REPETITION
RATE OF 25 Hz.
3. [Nuclear and Particle Physics Division]
SPECTROMETER PREPARATION IS IN PROGRESS.
CONSTRUCTION OF NEUTRINO FACILITY.
4TH INTERNATIONAL WORKSHOP ON NUCLEAR AND PARTICLE
PHYSICS AT J-PARC (NP08).
4. [Materials and Life Science Division]
IPS08 WAS SUCCESSFULLY HELD ON MARCH 5 TO MARCH 8
WITH 300 PARTICIPANTS INCLUDING 70 SCIENTISTS FROM 15
COUNTRIES.
5. [Nuclear Transmutation Section]
SPALLATION MATERIALS COOPERATION WITH PSI.
FUTURE EXPERIMENT FACILITIES FOR ACTINIDE.
6. [Safety Division]
ADVISORY COMMITTEE FOR 50GeV-MR AND MLF CONCLUDED
7. [Announcement of Symposia and Meetings]
8. [Editorial Note]
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1. [Overview] by Shoji NAGAMIYA
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EXCITING NEWS FROM THE 3 GEV ACCELERATOR
At the end of October we had a successful acceleration in the
3 GeV ring. Four months later, at the end of February of 2008, the
beam power per pulse reached 5 kW/pulse. Since the 3 GeV ring will
operate at 25 Hz (25 pulses per second), this power/pulse is
equivalent to 130 kW per second if 25 pulses were accelerated.
Since the neutron target is not yet ready to accept the primary
proton beam, the accelerator crew decided to deliver 50 kW beams
to a beam dump for about four minutes before the accelerator
operation was terminated for the March shutdown for machine
inspection. We had not expected to reach such a high power level
within the first four-month period after the injection and extraction
were achieved at 3 GeV. It is, therefore, exciting news for us.
Note that the goal at 3 GeV is 600 kW by using the present Linac
energy and 1 MW by boosting the Linac energy to 400 MeV.
MAJOR MILESTONES IN 2008
After the announcement of the JFY2008 budget in December
of 2007, we discussed internally major milestones within JFY2008.
With the support from both institutions, the J-PARC will keep the
following schedule:
May 2008 : Injection of the 3 GeV beam to the Main Ring.
June 2008 : Start to test production of the neutron beams.
December 2008: Open the usage of the Neutron and Muon facilities
to Users. Two operations cycles from December to February.
December 2008: Start of the tune of the Main Ring to 30 GeV.
After it is successful, the beam will be delivered to
the Hadron Experimental Hall.
March 2009: Completion of the Neutrino Experimental Area.
Based on the above schedule, the call for proposals for
neutron beams and muon beams will be announced in May of 2008.
IAC, A-TAC AND N-TAC
From the end of February to the beginning of March, the above
committee meetings were held, first Neutron Source Technical
Advisory Committee (N-TAC), then Accelerator Technical Advisory
Committee (A-TAC) and, finally, International Advisory Committee
(IAC). IAC praised a remarkable achievement during the past one year.
This committee, as usual, wrote several key comments and
recommendations. This year, the major issues written in the document
will be: a) the importance to obtain a sufficient operational fund, b)
the need of the energy recovery of Linac, c) the future needs of
spares and improvement, d) the management structure, etc.
The final report will be published soon.
THE FIRST J-PARC INTERNATIONAL SYMPOSIUM
From March 5 through March 7 the First J-PARC International
Symposium was held in Mito, which is the capital city for Ibaraki
Prefecture. Two major symposia dedicated to a) materials and life
science and b) particle and nuclear physics, respectively, were held
separately, whereas the joint session was held in the afternoon of
March 5. About 250 members participated in the former symposium
and 200 in the latter, with the total number of participants of 450.
Among them about one third were from abroad. Since J-PARC
will start its operation within JFY2008, many plans, dreams, and
future expansions were discussed at these two symposia.
USERS STEERING COMMITTEE
On March 17th, the entire afternoon was dedicated to discussion
of future possibilities at J-PARC. At the new Users Steering
Committee meeting six representatives from individual communities
described the current trends of the field and their expectations for
the future J-PARC. Talks covered a) high-energy physics
(S. Komamiya), b) nuclear physics (H. Tamura), c) neutron science
(K. Yamada), d) muon science (N. Nishida), e) nuclear
transmutation (T. Iwasaki), and f) industrial usage (J. Sugiyama and
K. Nishijima). All presentations covered current trends of the
individual fields, the immediate usage plan at the J-PARC and the
need(s) for future extensions. Discussions will continue in the
future and the report will be created in the fall of 2008.
NEW SECTIONS IN THE J-PARC CENTER
On April 1, three new sections will be created and they will
start their function: a) Operation Support Section (its function is
similar to Director Support Section), b) Information/Computation
Section and c) Public Relations Section. In addition, several
management people will be replaced. Details of the individual
names will be informed in a separate place. The total number
of the people working at the J-PARC Center is now about 400.
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2. [Accelerator Division] by Yoshishige YAMAZAKI
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ONE SHOT OF 1.07E13 PROTONS WAS EXTRACTED FROM THE
RCS AT 3 GeV, WITH A MODEST BEAM LOSS, CORRESPONDING
TO THE BEAM POWER OF 130 kW, IF OPERATED AT DESIGNED
REPETITION RATE OF 25 Hz.
As already reported, the 3-GeV Rapid-Cycling Synchrotron (RCS)
was ready for the beam injection to both the neutron production target
and the Main Ring (MR), which will start this May. In order to
reconstruct
the Personnel Protection System (PPS) for this beam commissioning, the
operation of the J-PARC accelerator was shut down for approximately
two months. At the end of the extensive beam study before this
shutdown, the beam study result was demonstrated as follows.
First, 4.4E12 protons were extracted from the RCS over 4 minutes at
the energy of 3 GeV and a repetition rate of 25 Hz. This corresponds
to the beam power of approximately 50 kW (note that the designed
number of protons accelerated and extracted is 8.3E13 at the designed
repetition rate of 25 Hz and at the designed energy of 3 GeV,
corresponding to the beam power of 1 MW). The operation was terminated
here, since the beam dump at the extraction can only accept the beam
power of 4 kW averaged for one hour. In this case, only one bucket was
filled rather than two available buckets. Second, the two buckets were
filled out to form two bunches in the RCS. In this way, 1.07E13 protons
were accelerated and extracted just once, although all the accelerator
components were in operation at a full repetition rate of 25 Hz. This
corresponds to a beam power of 130 kW, if the beam is injected at the
designed repetition rate of 25 Hz. In both cases, the linac beam with
the emittance of approximately a few pi mm mrad was directly injected
to the RCS without any painting, which is designed over the available
RCS aperture of 324 pi mm mrad to mitigate the space charge effect.
Even under this condition, the beam loss observed at the beam
collimator is only 6 percent, corresponding to 0.5 kW, which is well
below the designed capacity of 4 kW for the beam collimator. Here,
note that almost all of the beam loss occurred during the beam
injection. In the conventional lattice design, the beam inevitably
passes through the transition energy during the acceleration. At the
transition energy, no stabilizing mechanism works for the longitudinal
degree of freedom in such a way that the synchrotron frequency
becomes zero at the transition, inevitably giving rise to the beam loss.
In the J-PARC RCS lattice design, the transition energy was raised to
9 GeV, which is far above the operational energy, by choosing the
missing bend lattice. This can be the reason why no beam loss was
observed during the acceleration. The demonstrated result indicates
that the beam power of 130 kW is promising on the neutron production
target, if operated at 25 Hz, and that more beam power is promising,
if the beam is painted over the available RCS aperture.
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3. [Nuclear and Particle Physics Division]
by T. Takahashi, T. Tsukamoto and T. Komatsubara
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SPECTROMETER PREPARATION IS IN PROGRESS
In the initial phase of the Hadron Facility operation secondary
beams will be delivered to several nuclear physics experiments
set up at the K1.8 as well as K1.8-BR lines. The Superconducting
Kaon Spectrometer (SKS) which has been playing an important
role at KEK-PS for many years will be transferred from Tsukuba
and installed at K1.8 for the next-generation hypernuclear
spectroscopy. The 300-ton magnet has recently been
disassembled in the Tsukuba North Hall to make it ready for
transportation, and also for a super conducting (SC) coil
inspection at the factory, and the cryogenic system modification.
Instead of the current large He refrigerator, small GM-JT
refrigerators will be mounted taking the advantage of small heat
load of the magnet to facilitate not only easy and safe operation
but also to meet any magnet configuration requirement at K1.8.
Reassembly will take place within this year at J-PARC.
Detector elements for K1.8 and K1.8-BR experiments are now
also being prepared mostly by user groups. To accept a
high-intensity beam the development of an MWPC(DC) with
fine anode wire pitch was essential. Its readout electronics were
also developed in co-operation with the KEK Detector Technology
Project. A large-size drift chamber from Brookhaven National
Laboratory (BNL) will be recycled here also. An experiment will
be ready to accept the first beam at K1.8-BR followed by the
SKS experiments in 2009.
CONSTRUCTION OF NEUTRINO FACILITY
A half set of superconducting magnets was installed in the neutrino
beam tunnel in March. Installation of cooling water pipes and bus-bars
for the neutrino beam preparation section was finished and the
installation work of the final focus section has been started.
The neutrino 1st horn was delivered to J-PARC in March and was
stored in the Materials and Life Science Facility (MLF) building until
the horns will be installed in the neutrino Target Station (TS), which
will be available after the summer. Assembly work of the
Beam Dump (BD) for the neutrino beam line is being carried out.
There are 14 core modules which will be assembled at the beginning
of April and they will be assembled into the BD of which the weight is
more than 70t. The downstream Decay Volume (DV) pipes were
installed. Construction of the Neutrino Utility building 3 (NU3) and
the pit for the BD and the muon monitor are being carried in the
same construction area which will be ready for installation of equipment
after the summer. Neutrino Monitor (NM) pit construction was finished
for the structure under the ground level (wall and floors) by the end
of March. Installation work for the T2K-ND280 magnet has been
started, which will be finished by the end of June.
4TH INTERNATIONAL WORKSHOP ON NUCLEAR AND PARTICLE
PHYSICS AT J-PARC (NP08)
The NP08 workshop ( http://j-parc.jp/NP08/ ) was held from
March 5 to 7 at Mito City, which is adjacent to Tokai Village where
J-PARC is being constructed, with 200 participants. In the morning of
March 5, at the plenary session, an overview of the project
(S.Nagamiya),
the status of the accelerator complex (T.Koseki), and the continuity in
the physics program from BNL Alternating Gradient Sychrotron to
J-PARC (P.Pile) were presented. The afternoon session was a joint
session with the IPS08 international symposium (http://www.ips08.com/)
as "the 1st International Symposium on Science at J-PARC"
( http://j-parc.jp/NP08/html/JointSymposium.html ) to discuss all
the scientific topics in J-PARC including MLF. The parallel sessions
were held in the morning of March 5 and in the whole day of March 6,
and six working groups on Strangeness Nuclear Physics, Nuclear/
Hadron Physics, Kaon Rare Decay, Muon Decay, Neutron, and Neutrino
and Proton Decay enjoyed lively discussions. On March 7, the prospects
for particle physics (H.Murayama), the new projects of Project X at
Fermilab (Y-K.Kim) and GSI-FAIR (H.Gutbrod), and the reports from
working groups were presented. In the last session S.Nagamiya,
J-PARC Director, summarized the enthusiasm and plans of the
participants for long-term physics program after the completion
of the current J-PARC construction. As the post-workshop event,
a tour to the J-PARC site was made in the morning of March 8.
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4. [Materials and Life Science Division] by Yujiro IKEDA
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INTERNATIONAL SYMPOSIUM ON PULSED NEUTRON AND MUON
SCIENCES (IPS08) WAS SUCCESSFULLY HELD ON MARCH 5 TO
MARCH 8 WITH 300 PARTICIPANTS INCLUDING 70 SCIENTISTS
FROM 15 COUNTRIES.
1. Neutron Source
The proton beam extracted from the rapid cycle synchrotron (RCS)
was examined in terms of beam intensity and beam profile with the
beam monitors in the beam transport line (3NBT). As accelerator study
progressed, the maximal beam power of 50 kW and two-bunch
acceleration were confirmed. After improvements in a pair of hydrogen
pumps, the circulation test for the cryogenic hydrogen circulation
system
under a condition of 20 K and 1.4 MPa G has been completed.
On March 26, the system passed the complete examination related with
the High-pressure Gas Safety Law of Japan. A series of remote-handling
tests for the mercury target, moderators, the reflector plug and the
proton beam window by using actual components has been completed.
Commissioning tests of the general control system of Materials and
Life Science Facility (MLF-GCS) have been carried out for checking
its performance and interlocks, such as MPS, TPS and PPS.
2. Neutron Science
Since January, 2008, construction for instrument installation is
being performed intensively by many companies. More than 10
installations are being achieved in parallel under a tight schedule.
Since the Day-one instruments should be ready by the first beam
operation scheduled in the end of May, much rushing resulted. In order
to reduce risks of accidents, the construction procedures have been
monitored and MLF staff have patrolled the construction site regularly.
Instead of labors that were safe, frequent accidents, especially in
crane
operations, happened during these months. Very fortunately all of the
accidents were not serious and were not associated with any damage to
people. Hence, now we are very careful for safety for the construction.
TAKUMI (residual stress analysis diffractometer), SHRPD (high resolution
powder diffractometer), 4SEASONS (high intensity chopper instrument),
NOBORU (test port), iMATERIAL (powder diffractometer by Ibaraki
Prefecture), iBIX (protein crystal diffractometer by Ibaraki Pref.),
will
accept the first beam in May and call for proposals for December, when
we will start the first user programme of J-PARC with proton beam
power of higher than 20kW. For the development and construction of
neutron devices, scintillation detector development has been going well
in collaboration with the ISIS detector group. The first 1-d
scintillation
detector with fiber coded method for the engineering diffractometer
TAKUMI has been constructed and tested. A prototype of a 2-d
compact scintillation detector with wavelength shifting fiber read out
for
the biomaterial single crystal diffractometer iBIX has been tested and
the production has been started. Fabrication of super-mirror guide
tubes with m=4 for the beam lines of chopper spectrometers has been
started by using a large scale ion beam sputtering instrument at
J-PARC.
3. Muon science
In the 2nd Hall in the MLF building, the concrete blocks
surrounding
the muon beam line were installed and the cryogenic system for cooling
the superconducting solenoid was almost finished. Many components for
the muon beam such as refurbished bending magnets, newly fabricated
slit boxes and beam blocker boxes are now stored in the Hall waiting for
installation. The commissioning work to establish the remote handling
operation in the remote handling room and in the hot cell was started.
The procedure to exchange monitor assemblies such as CT (current
transformer) and PM (profile monitor) were now successfully established,
and the study of the exchange process for the muon target is underway.
4. IPS08
About 300 people from around the world gathered at Mito, Japan,
March 5-8, 2008, at the height of the plum-tree blossom season. The
participants, coming from 15 countries, including U.S.A, UK, Germany,
Australia, Taiwan, France, Korea, Switzerland, China, Indonesia, Canada,
India, Sweden, Hungary, and Netherlands were devoted to discussions
for full three days from early morning to evening. Clearly, J-PARC MW
pulsed neutrons and muons will play a core role for promoting new
scientific research. The participants were enthusiastic about the
possibilities J-PARC offers.
5. User program for MLF use
A call for proposal of MLF use in this fiscal year, which is in
preparation, is scheduled to be announced in May, 2008. About 7
instruments are to be available for the users.
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5. [Nuclear Transmutation Section] by Kenji KIKUCHI
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SPALLATION MATERIALS COOPERATION WITH PSI
The J-PARC center agreed with the spallation neutron source
division of the Paul Scherrer Institut (PSI, Swiss) to cooperate in the
field of spallation materials technology development, which covers
exchange of information or personnel and post irradiation experiment
this February. Then substantial cooperation started: Pulling tests of
target cladding materials were done at PSI to evaluate mechanical
properties after two-year proton beam irradiation, and fatigue test
machine developed at J-PARC was transported to PSI.
FUTURE EXPERIMENT FACILITIES FOR ACTINIDE
The first joint meeting between JAEA and EUROTRANS was held
in February at Karlsruhe, Germany. The importance of the
international common roadmap to realize the transmutation of
nuclear wastes was discussed together with the technical aspects
of ADS development. In such a roadmap, the basic experiments
expected in J-PARC will play indispensable roles in the fields of
reactor physics of the transmutation systems and the spallation
target engineering.
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6. [Safety Division] by
by Minoru TAKASAKI, Taichi MIURA and Hiroshi NAKASHIMA
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ADVISORY COMMITTEE FOR 50GeV-MR AND MLF CONCLUDED
The first advisory committee, which was established for the 50 GeV
proton synchrotron (MR) and the Materials and Life Science Facility
(MLF) by the Ministry of Education, Culture, Sports, Science and
Technology (MEXT), met to deliberate the safety aspects on
October 26, 2007. The last and 6th committee was held on
March 11, 2008, to conclude the deliberation. According to suggestions
about the application of these facilities for the operation license,
a revised application form will be submitted to MEXT, the Tokai-Mura
Municipal and Ibaraki Prefecture Governments, shortly. The operation
license is expected to be issued around the end of April. The 6th
Expert Committee of J-PARC on the Interlock System met on
January 28, 2008, and mainly deliberated the interlock system of the
secondary beam line around the Hadron Experimental Facility.
The meeting for the general safety aspect of J-PARC was held on
March 13, 2008, and the revision of provisions which was brought about
by the organization reform was approved. In this fall, several
facilities
of J-PARC will be opened for users. Now preparations of a text book
about the general safety for users and a manual of emergency
procedures for foreigners are in progress towards the opening of
experimental facilities.
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7. [Announcement of Symposia and Meetings]
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8. [Editorial Note]
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Editorial Board:
Masatoshi ARAI (chair): masatoshi.arai@j-parc.jp
Yujiro IKEDA: yujiro.ikeda@jaea.go.jp
Nobuo OUCHI: nobuo.ouchi@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
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