NewsLetter#5
Masatoshi ARAI
masatoshi.arai at kek.jp
Mon Jul 16 11:06:43 CDT 2001
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JAERI-KEK Joint (JKJ) Project Newsletter No. 5 July, 2001
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High Intensity Proton Accelerator Project proposed jointly
by the Japan Atomic Energy Research Institute (JAERI)
and the High Energy Accelerator Research Organization (KEK)
http://jkj.tokai.jaeri.go.jp/
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1. Recent Progress of the Joint Project between JAERI and KEK on High-
Intensity Proton Accelerators (Shoji NAGAMIYA)
2. Report from the Accelerator Group (Yoshishige YAMAZAKI)
3. Report from the Nuclear and Particle Physics Experimental Facility
(Jun IMAZATO)
4. Report from the Neutron Science Group (Yujiro IKEDA)
(Materials & Life Science Experimental Facility Group)
5. Report from the Muon Science Group (Yasuhiro MIYAKE)
6. Report from the Accelerator Driven Transmutation (ADS)
Experimental Facility Group (Hiroyuki OIGAWA)
7. Announcement of symposium and meeting.
8. Editorial note
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1. Recent Progress of the Joint Project between JAERI and KEK on High-
Intensity Proton Accelerators
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by Shoji Nagamiya
The official construction of the accelerator started on April 1,
2001, which is the first day of the Japanese Fiscal Year. Since then,
a significant amount of progress has been made on negotiations between
JAERI and KEK on the Construction Agreement between the two and on the
structure of the construction team. The following project team is now
installed:
------------------ -------------------
| KEK Director | | JAERI President |
| H. Sugawara | | K. Murakami |
------------------ -------------------
| ------------------------ |
-------------| Steering Committee |-------------
| Y. Kimura & S. Saito |
------------------------
|
----------------- ------------------------ -------------
| International | | Project Headquarters | | Users |
| Advisory |----| Director: S. Nagamiya |----| Committee |
| Committee | | Deputy Director: | -------------
----------------- | H. Yokomizo |
-------------------------
|
----------------------------
| |
-------- --------
| | | |
| GR#1 | .......... | GR#8 |
| | | |
-------- --------
GR#1: Coordination (Y. Oyama and M. Takasaki)
GR#2: Accelerator (Y. Yamazaki)
GR#3: Materials and Life Science Experiments (Y. Ikeda)
GR#4: Nuclear and Particle Physics Experiments (J. Imazato)
GR#5: Transmutation Experiments (H. Oigawa)
GR#6: Facility and Building (H. Naruse and T. Yamada)
GR#7: Radiation Safety (N. Sasamoto and T. Shibata)
GR#8: Administration (T. Konashi and T. Sawada)
* Name(s) in the parenthesis is(are) the head(s) of the group.
Over 300 people from JAERI and KEK are presently working for the
project.
The first magnet for the 50 GeV Synchrotron was completed and
tested. Mass production will start soon. The RFQ and an initial part
of the drift-tube linac (DTL) were also completed. High-current
acceleration of proton beams through the RFQ and the DTL has been
achieved successfully.
The Tokai Village, in which the project will be constructed, will
soon conclude their attitude towards our project. It is expected that
the Village approves officially our project by taking into account the
voice of the local inhabitants on safety regulations and environmental
issues. The official vote will take place on July 18th.
Negotiations are underway with a) the Japanese Government for
next-year's budget and b) the Local Government on various details of
the method of using the JAERI land due to many regulations.
Two Committees ("International Advisory" and "Users" written in
the above chart) will be formed soon. The actual construction work is
gradually getting on track.
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2. Report from the Accelerator Group
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By Yoshishige YAMAZAKI
As reported several times the 60-MeV linac, which will be the low
energy front end of the Joint Project Proton Linac, is under construction
in a linac test building at KEK. At first, the construction was initiated
by the KEK supplementary budget of JFY1998. Now, this project continues
by the joint efforts of JAERI and KEK. It comprises an H-minus ion source,
a low-energy beam transport (LEBT), a 3-MeV RFQ linac, a medium-energy
beam transport (MEBT), a 50-MeV drift-tube linac (DTL), and a 60-MeV
separated DTL (SDTL). The commissioning of the RFQ linac with beam has
been completed recently. Ten mA of H-minus beam was accelerated with 95
percent transmission. The RFQ linac is equipped with the pi-mode
stabilizing loop, which was devised at KEK and will be also used for
the SNS.
The ion source is of the volume-production type without cesium,
which possibly lowers the discharge limit of the following RFQ linac.
The peak current obtained so far is only 12 mA in contrast to the
required value of 60 mA. Another effort is in progress in JAERI to
increase the peak current by introducing cesium. Forty mA has been
obtained, limited by the power of the arc power supply. The power supply
was recently upgraded to increase the beam current further and a peak
beam current of 70 mA has been obtained. Further efforts are necessary
to improve the emittance and long-term stability of the beam current.
The installation of the drift tubes for the DTL has been started
in a clean room of the linac test building. The prototypes of the
bending magnets for the 3-GeV ring and the 50-GeV ring, respectively,
are being tested in order to measure the magnetic field distributions.
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3. Report from the Nuclear and Particle Physics Experimental Facility
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by Jun IMAZATO
In the first phase of the experimental hall construction, one
primary beam lime, the A- line, will be installed with one production
target. The beam optics of this line were finalized in the last couple
of months, and the specifications of beam line elements were determined.
Based on the beam line layout plan, the conceptual design of the hall
building and extraction tunnel as well as the utility design are in
progress in the KEK construction department under very tight budgetary
constraints. The construction of the tunnel will begin in late fiscal
year 2002 and the hall will be completed in 2006.
In April, 2001, a working group for the facility construction was
formed in KEK-IPNS and started its activity. Several sub-teams are in
charge of 1) experimental hall and facility, 2) beam lines, 3) target
and beam monitor, 4) neutrino experiment facility, 5) cryogenics, 6)
network and electronics, and 7) other specialized technical support.
The primary objective of these groups is to develop and design beam-line
components and facility instruments that are operative under very high-
beam-intensity conditions or are used in high radiation environments.
All the instruments will be manufactured in 2004-2006 and installed in
time for beam commissioning, which is scheduled in late FY2006. Because
of budgetary constraints we will be forced to recycle a large fraction
of the components at the current KEK-PS. For R&D and for designing
elements, international cooperation will be very desirable, and we are
going to establish a scheme. There is also discussion to have an
international workshop by the end of 2001.
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4. Report from the Neutron Science Group
(Materials & Life Science Experimental Facility Group)
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by Yujiro Ikeda
A new framework has been established to carry out the facility
construction phase of the JKJ project, and all activities associated with
the 1-MW spallation neutron source development have been restructured
and integrated into a new group. The name of the group is the Materials
& Life Science Experimental Facility Group (Group leader: Yujiro Ikeda).
This group is the working body that is responsible for designing and
constructing the facilities relevant to the 3-GeV proton beam and
consists of six subgroups. The sub-group names and sub-group leaders are
as follows: Neutron Source (Masanori Kaminaga), Neutron spectrometer
(Masatoshi Arai) and Instrument & device (Michihiro Furusaka), Muon
science (Yasuhiro Miyake), Proton beam transportation (Schinichi
Sakamoto), and System integration (Ryutaro Hino). The planning and
coordination group is specifically charged to promote close interaction
between the facility and neutron science users. Under the initiative of
this function (Susumu Ikeda), extensive discussion is currently in
progress to identify the instruments to be equipped initially, and a
strategy for upgrades to meet the final goals of the project mission.
About 50 people are assigned as group members who are dedicated
to the neutron science project. To further reinforce the construction
activities, a collaboration mechanism is envisaged to enable extensive
contributions from the user community to the project.
In the course of establishing a reference set of the proposal for
the neutron facility instrumentation, a workshop will be held at KEK
on August 9, 2001.
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5. Report from the Muon Science Group
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by Yasuhiro MIYAKE
As mentioned above, the muon science subgroup is one of six
subgroups under the leadership of Dr. Y. Ikeda of JAERI for the
construction of the Materials and Life Science Facility. Its mission
is to accomplish the design and construction of:
1) the pion target with scrapers for the scattered protons,
2) the radiation shield and basic facilities in the primary
tunnel of the Materials and Life Science building,
3) the secondary muon beam lines, and
4) the building and facilities for muon science.
For Phase 1, one pion target will be installed upstream of the
neutron target. By collaborating with the 3NBT (3GeV-ring to Neutron-
facility Beam Transport) group, we are now working on the detailed design
of the tunnel structure of the primary proton beam line for the scenario
that only one pion target is installed, considering the configuration and
room for the primary line optics, the secondary beam optics, the pion
target, scrapers, air-ducts, cooling water facility, and shield blocks,
etc. One of the most important issues is to develop a design for the
air-circulating system, which not only must remove 70 kW of heat loss
from the magnets and power cables, but also can satisfy the constraints
on the fraction that can be ventilated (while maintaining the inside of
the primary proton line at negative pressure) to meet the requirement of
not violating the permitted radiation level in the boundary.
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6. Report from the Accelerator Driven Transmutation (ADS)
Experimental Facility Group
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by Hiroyuki OIGAWA
As part of the research and development for the ADS Target Test
Facility, a liquid Pb-Bi loop for the material test has been operated
under a flowing condition at 450 degree centigrade for more than 2400
hours. A materials corrosion test in stagnant Pb-Bi was also performed
for 500 hours at 550 degree centigrade. Oxide films were observed on
the surface of the materials in oxygen-saturated Pb-Bi. It was found
that the thickness of the oxide films tends to decrease with increasing
the chromium content in steel.
The conceptual design for the Transmutation Physics Experimental
Facility has continued, particularly for its safety aspects. The
conceptual design of the future ADS plant was reviewed from the viewpoint
of potential benefits of changing fuel composition, coolant / target
materials, and other key factors.
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7. Announcement of symposium and meeting.
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1) Workshop on Neutron Spectrometer
2001.8.9,10:00-17:00, 4th Building, KEK
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8. Editorial note
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Editorial Board:
Masatoshi ARAI (chair): masatoshi.arai at kek.jp
Koji YOSHIMURA koji.yoshimura at kek.jp
Yujiro IKEDA: ikeda at cens.tokai.jaeri.go.jp
Hideaki YOKOMIZO: yokomizo at linac.tokai.jaeri.go.jp
Shinya SAWADA: shinya.sawada at kek.jp
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