[Neutron] J-PARC Newsletter No.38

arai (J-PARC) masaarai at hotmail.co.jp
Thu Nov 12 11:10:22 CET 2009


===============================================================
J-PARC Project Newsletter

  No. 38, Nov. 2009

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

 

===============================================================

 

Hot news from J-PARC:

 

We have started a 120kW-operation since 10 November after serious 

improvements on the RFQ linac as described below. This is a big step 

for us from the 20kW-operation in the previous stages. The accelerators 

are working successfully with higher reliability now.

 

===

 

HEADLINES AND CONTENTS

 

1. [Overview]

 

LODGING WILL BE CONSTRUCTED BY KEK

 

OPEN HOUSE FOR J-PARC

 

ACCELERATOR REVIEW WAS CONDUCTED

 

FEE FOR PROPRIETARY EXPERIMENTS

 

2. [Accelerator Division]

 

BEAM COMMISSIONING RESTARTED WITH STEADY IMPROVEMENT OF

RFQ (RADIO-FREQUENCY QUADRUPOLE) LINAC

 

THE IMPREGNATED RESIN IS THE MAIN REASON FOR BUCKLING OF MA

(MAGNETIC ALLOY) CORE FOR RF CAVITIES

 

THE REPETITION CYCLE TIME OF MR (50-GeV Synchrotron) WAS

SHORTENED TO 3.52 SEC

 

3. [Nuclear and Particle Physics Division]

 

BEAMLINE AND DETECTOR INSTALLATION IS MAKING PROGRESS

IN THE HADRON HALL

 

STATUS OF NEUTRINO FACILITY

 

4. [Materials and Life Science Division]

 

5. [Exotic Nuclear Science Group]

 

THE INTERNATIONAL REVIEW COMMITTEE WAS HELD FOR A NEW

EXPERIMENTAL RESEARCH PROJECT PROPOSED BY RNB GROUP

 

STRUCTURE OF 11Be WAS STUDIED BY USING 9Li RADIOACTIVE

NUCLEAR BEAMS AT TOKAI RADIOACTIVE ION ACCELERATOR

COMPLEX (TRIAC)

 

SELF-DIFFUSION COEFFICIENTS IN ELECTROLYTE FOR LITHIUM ION

BATTERY WERE DIRECTLY MEASURED AT TRIAC

 

6. [Nuclear Transmutation Section]

 

NEEDS OF R&D FACILITIES IN NUCLEAR SCIENCE

 

7. [Safety Division]

 

APPLICATION FOR OPERATION LICENCES WERE SUBMITTED TO MEXT

 

8. [Announcement of Symposia and Meetings]

 

9. [Editorial Note]

 

 

-----------------------------------------------------------

1. [Overview] by Shoji NAGAMIYA

-----------------------------------------------------------

 

 LOGDING WILL BE CONSTRUCTED BY KEK

 

     For a long time, we have requested "lodging" for users. Very

recently KEK decided to construct 52 rooms for users on the site of 

the Ibaraki Quantum Beam Research Center, where the Users Office 

and office space for users are currently located. The anticipated

completion of this lodging will be sometime near the end of 2010 or,

at the latest, the beginning of 2011. We have also requested 

construction of a hotel by Tokai Village. We were told that the effort 

to construct a new hotel will still continue, even if the lodging is 

constructed by KEK.

 

 OPEN HOUSE FOR J-PARC

 

     On August 1 we had an open house for J-PARC. This year, the

open house was hosted by both J-PARC and Tokai Research Center.

We had 4600 visitors among which 3700 were J-PARC visitors. Last

year we had 2600 visitors for the J-PARC, so the number increased

substantially this year. We shall have an open house once a year

in coming years.

 

 ACCELERATOR REVIEW WAS CONDUCTED

 

     On July 29 an accelerator review was conducted (chair is

Professor Oide from KEK). This time, the main purposes of the

review are on 1) technical feasibility of approaching 1 MW, 2)

financial constraints to achieve it, and 3) the best strategy for

the future. Based on this review, the next stage is to discuss with

the user communities if the current strategy presented by the

accelerator group is agreeable to the communities. I will

report the results of these discussions in the next issue of

the Newsletter.

 

 FEE FOR PROPRIETARY EXPERIMENTS

 

     Since last December the beam time has been open for neutron

users. Recently, an industrial usage started to come, though

we have not yet settled how much the actual charge is for

proprietary experiments without any publications. The Government

started to agree with the fee which is comparable to SPring-8.

For any work for which the results are published, the beam time

charge is free at J-PARC.

 

 

-------------------------------------------------------------

2. [Accelerator Division] by Ainosuke ANDO

-------------------------------------------------------------

 

 BEAM COMMISSIONING RESTARTED WITH STEADY IMPROVEMENT

OF RFQ (RADIO-FREQUENCY QUADRUPOLE) LINAC

 

     Beam Commissioning restarted on October 1 after the summer

shutdown for the maintenance of the accelerators and the improvement

of the RFQ linac. In the improvement, two cryopumps of 4000 L/s each

and two SIP's (Sputtering Ion Pumps) of 800 and 400 L/s were added

to the existing evacuation-pumping system, and a mass separator to 

obtain clear information of outgassing was installed. An additional TMP 

(Turbo Molecular Pump) of 500 L/s was also installed in the LEBT (Low 

Energy Beam Transport between the ion source and the RFQ), which was

replaced by a new one with orifices at both ends to reduce the

unnecessary flow of H- ions and hydrogen. The operation of RCS (3-GeV

Rapid Cycling Synchrotron) has been restarted with the LINAC beam at 

first of 5 mA in peak current and 0.1 msec pulse width to ensure the 

stable beam output of 20 kW from RCS in October. In the next stage,

the pulse width will be expanded to 0.5 msec for 100 kW of RCS, and

then the peak current will be raised to 15 mA for 300 kW of RCS.

The demonstrated operation with the RCS beam output of 200 kW in

70 seconds and equivalent 310 kW in one shot in September 2008 will

be routine if there are no troubles in hardware and the beam loss

issues are solved.

 

 

 THE IMPREGNATED RESIN IS THE MAIN REASON FOR BUCKLING OF

MA (MAGNETIC ALLOY) CORE FOR RF CAVITIES

 

     Buckling or stress deformation has been found in many MA cores

for the RF cavities of RCS as reported in Newsletter #36.

Investigation for the correlation between the damaged cores and their

manufacturing processes clarifies that the existence of the impregnated

resin, of which the coefficient of linear expansion is larger than that

of the MA alloy by about 8 times, prevents any room for expansion of

MA alloy ribbons. Although the impregnation of the resin with light 

viscosity was adopted in R&D to make a core more rigid, the original 

process without impregnation is re-adopted to restore only the 

original purpose.

 

 

 THE REPETITION CYCLE TIME OF MR (50-GeV Synchrotron) WAS

SHORTENED TO 3.52 SEC

 

     As the improvement of the power supplies for the main magnets

(bending and quadrupole magnets) resulted in the shorter rise and fall

time (still not enough for the design values), the cycle time of MR is

shortened to 3.52 sec for the FX mode (Fast Extraction for the neutrino

target). MR is operated in the two modes of FX and SX (Slow Extraction

for the hadron target) from October. In the SX mode, the cycle time

is still 6 sec with the 30-GeV flat-top of 2 ~ 3 sec; enough for favorite

beam manipulation or gymnastics.

 

 

-----------------------------------------------------------

3. [Nuclear and Particle Physics Division]

by Toshiyuki TAKAHASHI and Hiroaki WATANABE

by Masahiro SHIBATA, Yoshiaki YAMADA and Toshifumi TSUKAMOTO

-----------------------------------------------------------

 

 BEAMLINE AND DETECTOR INSTALLATION IS MAKING

PROGRESS IN THE HADRON HALL

 

     Preceding the further commissioning of the accelerator MR and

the eventual slow beam delivery to the Hadron Hall in this autumn,

the installation of beamlines is making progress. Following the

completion of K1.8BR in January 2009, the K1.8 beamline will be

completed soon as the extension of K1.8BR. K1.8 delivers

separated charged meson beams up to 2.0 GeV/c, at which primarily

hypernuclear spectroscopy will be performed. In particular,

the study of the double strangeness system will be a topic in Day-1

experiments. The beamline has already been tested for all

the magnets and equipped with a second electrostatic separator

in the extended section. In the experimental area the high-resolution

Superconducting Kaon Spectrometer (SKS) is now being set up.

The magnet had already been moved from KEK-PS with some

modifications in the cryogenic system. The magnet has been 

successfully cooled down and excited. Detector mounting is 

also ongoing by the user group.

 

     On the other side of the primary beamline, the construction of

the neutral kaon line KL has been also finished. The beamline

consists of two sets of movable collimators and a sweeping magnet 

between them and should deliver a K_L beam with very suppressed

halo-neutron background. The E14 KOTO experiment (the rare decay

experiment KL-> pi0nu nu-bar) will be performed with an

international collaboration. In this autumn, the beam survey

is scheduled, in terms of the K_L yield measurement as well as

the beam quality study.

 

 STATUS OF NEUTRINO FACILITY

 

     The primary proton beam line of the neutrino facility has four 

types of proton beam monitors, namely intensity, position, profile and 

beam loss monitors. Five CTs (Current Transformers) are installed as

intensity monitors. 2% precision was achieved in the previous

commissioning. Twenty one ESMs (ElectroStatic Monitors) are installed

to measure beam position. Present typical resolution is 0.6 mm and

we are working to improve the resolution by understanding the 

background to the signal. Nineteen SSEMs (Segmented Secondary 

Emission monitors) are installed as profile monitors. Obtained resolution 

is 0.2 mm for position and width. Fifty BLMs (Beam Loss Monitors) are 

placed around the beam line. No significant beam loss was observed in 

the previous commissioning except for beam loss from foils of the 

SSEMs. This indicates that the total beam loss was less than 0.1 

percent. In the summer shutdown, ESM and SSEM re-alignment work 

was carried out and software was upgraded to deal with multi-bunch 

beam in addition to analysis of obtained data. Now we are ready for 

beam commissioning from October.

 

     For the beam run with higher beam power in Autumn, the second

and third horns were installed into the Helium vessel on July 10th

and August 6th, respectively. Then, simultaneous test operation with

1st, 2nd and 3rd horns successfully finished in September. The helium

vessel is now under an evacuation test, and will be filled with 1500m3

of helium gas soon. The Autumn beam run will start after the final 

test operation of horns in He gas.

 

     The installation work of the T2K near detectors is ongoing

at the NM (Neutrino Monitor) building. A neutrino beam monitor,

INGRID (Interactive Neutrino GRID detectors), was successfully

installed in August. The commissioning and calibration of INGRID is

being carried out to be ready for the neutrino beam in October.

As a part of the off-axis neutrino detectors, the P0D(Pi-zero 

Detector), the FGD (Fine Grained Detector), and the DSECAL 

(DownStream Electromagnetic CALorimeter) were tested on surface 

and were installed in the detector support structure, called BASKET.

Two TPC (Time Projection Chamber) modules will be shortly

installed this October. The work of cabling and piping is being

carried out, and the commissioning of the detectors will follow.

The T2K off-axis neutrino detector is scheduled to be ready for

operation in December.

 

 

-----------------------------------------------------------

4. [Materials and Life Science Division] by Yujiro IKEDA

-----------------------------------------------------------

 

 1. Neutron Source

     In the summer maintenance period, annual voluntary inspection

of the cryogenic hydrogen system was completed successfully.

A vibration measuring system for the hydrogen circulation pump

was installed to evaluate abnormal pump rotating conditions.

Some remote-controlled cameras in the hot cell were modified

to move on rails for better visibility in replacement work

of activated components such as moderators.

 

     The tunnel of the proton beam transport line was surveyed and

the uneven subsidence was found to be a maximum of 1 mm for the

last year. The magnets and the beam monitors were realigned

in this summer shutdown period with the accuracy better

than 0.1 mm.

 

     The fabrication of the spare of target vessel was continued

to fix the safety hull on the mercury vessel. As for R&D on the

pressure wave mitigation, the micro-bubble distribution in the

target vessel was measured at the tetrathiafulvalene (TTF)

mercury loop of Oak Ridge National Laboratory (ORNL)

under collaboration with the Spallation Neutron Source (SNS).

 

 2. Neutron Science

     Various maintenance and improvements have been carried out in 

twelve BL's during the Summer shutdown. A large vacuum tank with a 

volume of 50 m3 (the weight of 40t) for the High Resolution Chopper 

Spectrometer (HRC) was installed at BL12. A small vacuum tank and 

six gas-filled tanks with a total volume of 20 m3 for the super high 

resolution powder diffractometer (SuperHRPD) was installed at BL08 

after the removal of the second-hand chamber. The installation of 

3He detectors for both BL08 and BL12 are now underway.

 

     Disk choppers maintenance and the confirmation of the guide tube

alignment were carried out in the Disk-Chopper Spectrometer

(AMATERAS) at BL14, and in the Engineering diffractometer (Takumi)

at BL19. Maintenance of detectors and electronics etc. were carried

out in most of the BL's.

 

     User operation for the 2009A period (the first half of FY2009)

has been re-started on Oct. 12. 105 accepted experiments out of

116 proposals will be carried out during the period of 2009A.

The first result of the High Intensity Chopper Spectrometer

(4Seasons, BL01) utilizing the new technique of "the Multiple Incident

Energies" has been published and selected as the Editor's choice of

the Journal of the Physical Society of Japan (J. Phys. Soc. Jpn. 78

(2009) 093002).

 

 3. Neutron Optics and Detectors

     A neutron focusing device consisting of a spheroidal supermirror

(m=2) has been developed by using an ion beam sputtering instrument.

Elliptical mirror optics, which have no chromatic aberration, can be

effectively used for manipulating a wide range of wavelengths of

neutrons especially at pulsed neutron sources. The performance of

this optical system can be increased by using a spheroidal geometry

which increases the aperture ratio, and by using supermirrors which

increase the critical angle of total reflection.

 

 4. Muon Science

     The designs of the muon production target and the two sets of

scrapers are such that they are both placed in one large vacuum

chamber in order to make remote handling simple during maintenance

work. Particular care was given to the means of mounting the target,

moving and inserting the target with the required precision, as well

as cooling, monitoring, and changing the target in the hot cell, 

assuming that all of the work is intended to be done from the top of 

the maintenance area. Also we fabricated a dedicated muon cask,

together with a stand to position it on top of the target chamber

with good precision, for the maintenance of the muon target assembly,

the scraper assembly, and the profile monitor assembly.

 

     During the summer shutdown of 2009, we have had a commissioning

test of exchanging the irradiated muon target assembly having about

50 mSv/h of dose on its surface. The irradiated target assembly was

lifted into the cask, and moved into the hot cell. In the hot cell, the

target assembly was successfully transferred into the dedicated stand

for the muon target assembly. After several measurements such as

dose and dimensions, the target assembly was put back into the target

chamber in the proton beam line.

 

 

-----------------------------------------------------------

5. [Exotic Nuclear Science Group] by Hiroari MIYATAKE

-----------------------------------------------------------

 

 THE INTERNATIONAL REVIEW COMMITTEE WAS HELD FOR A NEW

EXPERIMENTAL RESEARCH PROJECT PROPOSED BY RNB GROUP

 

     A new experimental research project is proposed by a research

group of the radioactive nuclear beams (RNB group) to understand the 

rapid neutron capture process nucleosynthesis by an intensive study 

on the decay nature of N = 126 waiting point isotones and nearby nuclei.

An international review committee for the proposal was held on July 16.

The committee appreciates a new initiative of RNB group in this

research region.

 

 

 STRUCTURE OF 11Be WAS STUDIED BY USING 9Li RADIOACTIVE

NUCLEAR BEAMS AT TOKAI RADIOACTIVE ION ACCELERATOR

COMPLEX (TRIAC)

 

     The elastic resonance scattering experiment of 9Li and deuteron 

was successfully performed to study the structure of 11Be during 

1-4, Oct. The radioactive nuclear beam (RNB) of 9Li, whose half-life 

is 0.178 second, was accelerated with the energy of 0.85 MeV/u, 

purity of almost 100% and intensity of 5*104 particles per second.

 

 

 SELF-DIFFUSION COEFFICIENTS IN ELECTROLYTE FOR LITHIUM 

ION BATTERY WERE DIRECTLY MEASURED AT TRIAC

 

     LLTO (Li3xLa2/3-xTiO3) and LVSO (Li3VO4/Li4SiO4) are

candidates for the electrolyte of a solid-state lithium ion battery.

Self-diffusion coefficients for Li in those materials were directly

measured for the first time, using 8Li RNB from TRIAC during 

19-23, Sept. The detailed analysis is in progress.

 

 

-----------------------------------------------------------

6. [Nuclear Transmutation Section] by Hirofumi TSUJIMOTO

-----------------------------------------------------------

 

 NEEDS OF R&D FACILITIES IN NUCLEAR SCIENCE

 

     A report on "Research & Test Facilities Required in Nuclear

Science & Technology" was published by the Organization for Economic

Cooperation and Development (OECD) Nuclear Energy Agency.

The report says that the Transmutation Experimental Facility under

the J-PARC project is expected to play important roles in 

establishment of the technical basis to deal with minor actinide (MA) 

in nuclear energy systems and to couple a proton accelerator with 

a fast spectrum reactor.

(http://www.nea.fr/html/science/reports/2009/6293

-Research-Test-Facilities.pdf)

 

     The first meeting of the expert group on Integral Experiments

for Minor Actinide Management was held in September at

the headquarters of OECD/NEA. This expert group was established

by the Nuclear Science Committee to review integral experiments 

for validating MA nuclear data critically, as well as to recommend 

additional integral experiments needed for validating MA nuclear 

data and to investigate the possibility of establishing an international

framework for facilitating integral experiments for MA management.

The Expert Group will complete and document their activities within

two years.

 

 

-----------------------------------------------------------

7. [Safety Division] by Taichi MIURA and Hiroshi NAKASHIMA

-----------------------------------------------------------

 

 APPLICATION FOR OPERATION LICENSES WERE SUBMITTED TO MEXT

 

 

     Applications for licenses for the operation of the Nuclear and

Particle Physics Facility (HD) and the Materials and Life Science

Facility (MLF), 50GeV proton synchrotron (MR), the Neutrino

Experimental Facility (NU) were submitted to the Ministry of Education,

Culture, Sports, Science and Technology (MEXT) on June 24.

The main change points are the enlargement of a secondary beam

line in HD :K1.1, the collimator installation in the secondary beam line

BL10 in MLF, and the beam-intensity upgrade in HD, MR and NU.

The application for the operation of HD, MLF, MR and NU was

granted by MEXT on September 25.

 

 

-----------------------------------------------------------

8. [Announcement of Symposia and Meetings]

-----------------------------------------------------------

 

 

----------------------------------------------------------

9. [Editorial Note]

-----------------------------------------------------------

 

In case you do not wish to receive this Newsletter in the future,

please send an email to news-l-ctl at 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:

Masatoshi ARAI (chair): masatoshi.arai at j-parc.jp

Fujio MAEKAWA: maekawa.fujio at jaea.go.jp

Nobuo OUCHI: ouchi.nobuo at jaea.go.jp

Shinya SAWADA: shinya.sawada at kek.jp

Toshifumi TSUKAMOTO: toshifumi.tsukamoto at kek.jp

English Editor: Dick MISCHKE mischke at triumf.ca

Secretary: Chikako KAIBARA kaibara.chikako at jaea.go.jp

++++++++++++++++End of Letter+++++++++++++++++++++++++++++++++
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://neutronsources.org/pipermail/neutron/attachments/20091112/a5b5e0fc/attachment-0002.html>


More information about the Neutron mailing list