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Ikegami, Masanori*; Ueno, Akira
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), p.61 - 69, 2007/04
The beam commissioning of J-PARC linac has been started since November 2006 with the reduced beam energy of 181 MeV. This series of beam commissioning is to be continued until June 2007, and about three fourths of it has been completed as of April 2007. In this paper, we present commissioning results obtained to date together with the commissioning problems and issues experienced so far. We also briefly touch upon the commissioning plans hereafter.
in JSNSMaekawa, Fujio; Oikawa, Kenichi; Harada, Masahide; Kai, Tetsuya; Meigo, Shinichiro; Kasugai, Yoshimi; Oi, Motoki; Sakai, Kenji; Teshigawara, Makoto; Hasegawa, Shoichi; et al.
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), p.118 - 126, 2007/00
One of 23 neutron beam lines of JSNS, NOBORU, has been assigned to the Neutron Facility Group of JAEA. The primary mission of NOBORU is to investigate neutronic performance of JSNS while it can accommodate various trial research experiments. This paper describes an experimental program by using NOBORU mostly in an on-beam commissioning period of JSNS after the first proton beam acceptance in 2008. Topics for the primary mission to be studied are as follows; relationships between operating parameters of JSNS and neutronic performance, acquisition of beam parameters for users, confirmation of integrity in main components of JSNS, validation of neutronic designs, and research and development on measuring techniques. In addition, we are interested in radiography, introduction of a high-pressure instrument and eV neutron spectroscopy, and also welcome trial uses to bring out new research activities.
Harada, Masahide; Maekawa, Fujio; Teshigawara, Makoto; Watanabe, Noboru*; Kato, Takashi; Ikeda, Yujiro
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), p.616 - 626, 2007/00
no abstracts in English
Oikawa, Kenichi; Takada, Hiroshi; Maekawa, Fujio; Harada, Masahide; Kato, Takashi; Ikeda, Yujiro
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), p.591 - 597, 2007/00
The neutron beam shutter system of JSNS target station in the Materials and Life Science Experimental Facility (MLF) is now in the final stage of the construction. The JSNS shutter system consists of following components; (1) shutter base plates, (2) interstitial blocks, (3) shutter gates, (4) upper shielding blocks, (5) drive assemblies, (6) control systems, and (7) maintenance tools. This shutter system has 23 independent shutter gates and drive systems for each beam port, and its dimensions and materials have been designed to shield/provide the neutron beam of maximum size; 100 mm 
100 mm. The detailed construction steps of our shutter system, especially in its alignment, will be presented in the session.
Takahashi, Nobuaki; Shibata, Kaoru; Sato, Taku*; Nakajima, Kenji; Kajimoto, Ryoichi; Oikawa, Kenichi; Arai, Masatoshi; Schanzer, C.*
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), p.373 - 381, 2007/00
A time-of-flight near-backscattering neutron inelastic spectrometer, DIANA has been proposed for the Materials and Life science experimental Facility (MLF) at Japan Proton Accelerator Research Complex (J-PARC). It has been designed to achieve a high neutron flux at a range of low energies, whose wavelength band is between about 1.4 
and 6.4 . We have recently decided to attach the instrument to the coupled moderator source beam-line instead of the decoupled source beam-line, in order to achieve highest intensity at the desired wavelength band. On the other hand, a novel focusing analyzer has been theoretically developed and also designed for the instrument. As a result of this work, it is found that a large beam divergence at the sample is acceptable. Therefore, we have reconsidered the guide system in order to maximize the intensity, according to the report about advanced geometries for neutron guides.
Maruyama, Ryuji; Yamazaki, Dai; Ebisawa, Toru*; Hino, Masahiro*; Soyama, Kazuhiko
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), p.197 - 200, 2007/00
The development of high performance neutron supermirrors with high reflectivity and large 
, the ratio of the effective critical angle of the supermirror to that of natural nickel, is important for the J-PARC project since it greatly increases the available neutron intensity. Neutron supermirrors consist of alternating layers of two materials with different refractive indices for neutrons. An ion beam sputtering instrument with an effective deposition area of 0.2 m
has been installed at the Japan Atomic Energy Agency in order to produce neutron guides, benders, and other neutron optical devices, which are planned for application in the J-PARC project. We have succeeded in fabricating the supermirror with large critical angle of 
and that with high reflectivity (
85%) for 
.
Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Okamoto, Yoshihisa; Futakawa, Masatoshi; Kaminaga, Masanori; Kato, Takashi
Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), 14 Pages, 2007/00
The construction of the 1MW class mercury target which is the world highest level as the spallation neutron source is going on under the J-PARC project. The mercury target system consists of the mercury target vessel, the mercury circulation system and the target trolley. The outline of the mercury target system and several topics appeared in the course of the system fabrication and assembling are reported. For the target vessel, the residual stress at the beam window was evaluated and it was confirmed that the stress level is low and no problem. For the mercury pump, the mechanical EM pump which is free of mercury leak was developed and we could get prospect that the pump can be used under the beam condition of up to 400kW. For the target trolley, we confirmed that the very heavy body which is nearly 300t can be positioned with the accuracy of 
1mm which is required for the system operation.
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Nakajima, Kenji; Nakamura, Mitsutaka; Inamura, Yasuhiro; Maruyama, Ryuji; Soyama, Kazuhiko; Suzuya, Kentaro; Ino, Takashi*; Oyama, Kenji*; et al.
no journal, ,
4SEASONS is a chopper-type inelastic neutron spectrometer, and one of the day-one instruments at the spallation neutron source facility in Japan Proton Accelerator Research Complex (J-PARC). The targeted energy range is 5-300meV, and the spectrometer is optimized in intensity in this energy range by moderating the resolutions (
% at 
), by incorporating an efficient beam transport system, and by realizing multi incident energy (
) measurement. The high intensity and efficiency available at 4SEASONS make this spectrometer suitable for study of novel quantum phenomena in high-
superconductors and related systems. In the present paper, we will report the current status of the development and the construction of 4SEASONS, such as construction of the vacuum tank and the shielding, development of the new Fermi chopper for the multi- measurement, 2.5m-long 
He PSDs, and the beam transport system.
Ishigaki, Toru; Hoshikawa, Akinori; Yonemura, Masao*; Kamiyama, Takashi*; Aizawa, Kazuya; Sakuma, Takashi*; Tomota, Yo*; Morii, Yukio; Arai, Masatoshi; Hayashi, Makoto*; et al.
no journal, ,
Ibaraki prefecture, the local government of the area for J-PARC site, was decided to build a versatile neutron diffractometer (IBARAKI Materials Design Diffractometer) to promote an industrial application for neutron beam in J-PARC. This diffractometer is planned to be a high throughput diffractometer so that materials engineers and scientists can use it like the chemical analytical instruments in their materials development process. It covers in d range 0.18 
d () 5 with 
d/d = 0.16 % at high resolution bank, and covers d () 800 with gradually changing resolution at three detector bank (90 degree, low angle and small angle). Typical measuring time to obtain a "Rietveld-quality" data is several minutes with the sample size of laboratory X-ray diffractometer. To promote industrial application, a utilization system for this diffractometer is required. We will establish a support system for both academic and industrial users who are willing to use neutron but have not been familiar with neutron diffraction. The construction of this instrument was already beginning and will be completed in the beginning of 2008, as one of day-one instruments for J-PARC. The current status for this instrument also will be reported.
Takahashi, Nobuaki; Shibata, Kaoru; Sato, Taku*; Arai, Masatoshi; Mezei, F.*
no journal, ,
An inverted-geometry neutron inelastic spectrometer, DIANA has been proposed for the Materials and Life Science Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). It has been planned to have three crystal analyzer-banks, pyrolytic graphite PG(002), Ge(311) and Si(111) at near-backscattering configurations to study dynamics of biomolecules and proteins in wide energy transfer and momentum transfer ranges. In general, layout of small crystal-chips on an analyzer-bank is crucial for inverted-geometry spectrometers. We have developed a novel configuration concept of crystal-chips for inverted-geometry TOF spectrometers, which simultaneously achieves time-focusing, spatial-focusing and momentum-correcting abilities. This concept was adopted for the planned spectrometer, DIANA. In the conference, we will discuss the new analyzer layout, and then, will show the focusing performances as evaluated by Monte-Carlo simulations using McStas.
Nakamura, Mitsutaka; Nakajima, Kenji; Kajimoto, Ryoichi; Yokoo, Tetsuya*; Krist, T.*; Arai, Masatoshi
no journal, ,
Inelastic neutron scattering measurement utilizing the multiple incident energies (multi-
measurement) is a promising method to improve the measurement efficiency of chopper spectrometers at pulsed neutron sources. Multi- measurement can eliminate the detection dead time in time-of-flight measurement. We have been considering the instrumental design and novel device to realize the multi- measurement in several types of chopper spectrometer. In this presentation, the result of a series of considerations will be given. Particularly, we will introduce the disk-chopper arrangements for multi disk-chopper type spectrometer, and also the supermirror coated slit package system for Fermi chopper type spectrometer.
Ohara, Takashi; Kurihara, Kazuo; Kusaka, Katsuhiro; Hosoya, Takaaki; Tanaka, Ichiro*; Niimura, Nobuo*; Ozeki, Tomoji*; Aizawa, Kazuya; Morii, Yukio; Arai, Masatoshi; et al.
no journal, ,
Ibaraki Prefectural Government in Japan has started to construct a TOF single crystal neutron diffractometer for biological macromolecules for industrial use at J-PARC. For this diffractometer, design of an efficient neutron transportation system is important because this diffractometer has 40m source-sample distance. Recently, we designed a supermirror neutron guide which can transport 0.7-3.8 Angstrom neutron efficiently. The total length of the mirror section is 25m. At the first 17m, the mirror has curvature (R=4300m) for horizontal direction in order to remove high-energy neutron and 
ray. Simultaneously, all of the mirror section has tapered angle for vertical direction in order to reduce the frequency of neutron reflection at the surface of the supermirror. The neutron flux and profile at the sample position was calculated by Monte Carlo simulation softwares, McStas and IDEAS and compared with a curved, non-tapered guide we had designed previously. In result, the new supermirror system has 2 times gain for 0.7 Angstrom neutron and 1.5 times for 1.5 Angstrom neutron, and the beam profile at the sample position has a rectangular shape.
Kikuchi, Kenji
no journal, ,
Lead bismuth spallation target in accelerator driven system will provide a high intensity neutron source. Achievement and issues are summarized from ponts of views of high power spallation neutron source development.
Kikuchi, Kenji; Takenaka, Nobuyuki*; Kawai, Masayoshi*; Miwa, Hideki*
no journal, ,
Ta claded W generates decay heat after proton bombardment in the spallation target station. Assuming a loss of coolant, water feeding experiment was done and integrity of solid target was investigated if a peeling-off of claded material was caused or not.
Kusaka, Katsuhiro; Ohara, Takashi; Tanaka, Ichiro*; Niimura, Nobuo*; Kurihara, Kazuo; Hosoya, Takaaki; Ozeki, Tomoji*; Aizawa, Kazuya; Morii, Yukio; Arai, Masatoshi; et al.
no journal, ,
Ibaraki prefecture has started to construct IBARAKI biological crystal diffractometer for industrial use at MLF, J-PARC. It is designed to achieve the efficiency which is more than 50 times larger than the present high performance diffractometer BIX-4. To realize this performance, the diffractometer will be installed on a coupled moderator has more intense peak but wider pulse shape than a decoupled one. It is expected that some neighbor Bragg spots will overlap partially each other along the time axis. We should develop the data reduction software system for the diffractometer including the program of peak de-convolution with fast algorism. The detector configuration should be also important to realize high performance for measurement speed and data accuracy. The strategy of data collection, the strategy of de-convoluting overlapped Bragg spots and its validity will be reported based on the results of the simulations with the original programs.
Inamura, Yasuhiro; Kajimoto, Ryoichi; Nakajima, Kenji; Arai, Masatoshi
no journal, ,
We report the plan and current status of development for software used on high-intensity chopper spectrometer, 4SEASONS, and Cold Neutron Disk-Chopper Spectrometer, CNDCS, at Materials and Life Science Facility(MLF), J-PARC. We begin to design software packages based on many required functions for performing experiments and analysis with user-friendly and flexible interface. On the other hand, the emphasis in our software development lies on keeping smooth flow of several experimental steps from the maintenance of spectrometer to data analysis. In this presentation, we will present the detail design of a series of software packages and the current status of development works.
Hasegawa, Kazuo
no journal, ,
The J-PARC linac provides a 400-MeV beam to the 3-GeV Rapid Cycling Synchrotron at 25 Hz. The linac consists of 3 MeV RFQ, 50 MeV DTL, 191 MeV Separated-type DTL (SDTL) and 400 MeV Annular Coupled Structure linac (ACS). In the second phase of the J-PARC project, a 600 MeV beam by using a superconducting linac will be provided for the ADS applications. The RF frequencies are 324 MHz for the low energy structures and 972 MHz for the high energy structures. The energy of the linac, however, is reduced to 181 MeV for the time being, and it will be increased to 400 MeV in the near future. The beam commissioning was started in November 2006, and the beam energy was successfully accomplished to 181 MeV in January 2007. The status of the J-PARC linac components will be described in this paper.
Takata, Shinichi; Suzuki, Junichi; Shinohara, Takenao; Oku, Takayuki; Suzuya, Kentaro; Aizawa, Kazuya; Otomo, Toshiya*; Arai, Masatoshi
no journal, ,
For the clarification and enhancement of function of biological molecules with nm size, we believe that small-angle neutron scattering measurement in wide-q range giving structural information of the molecules with atomic resolution is important. We have thus designed the high-intensity small-angle neutron scattering instrument HI-SANS for the J-PARC in order to carry out the efficient measurement in wide-q range including high-q range of 1-100 nm
. In the design work we have performed Monte Carlo simulation of neutron scattering from typical proteins in solution using the scattering function based on the Debye formula. In this paper we present the q-resolution required from the simulation and then show detector arrangement to realize the q-resolution and counting efficiency expected with the detector arrangement.
Hasegawa, Shoichi; Aso, Tomokazu; Tatsumoto, Hideki; Otsu, Kiichi; Uehara, Toshiaki; Kawakami, Yoshihiko*; Sakurayama, Hisashi; Kato, Takashi
no journal, ,
In JSNS, supercritical hydrogen is adopted as a moderator material. A heat load of moderators is changed by fluctuation of nuclear heating due to pulsed proton beam. The maximum nuclear heating is estimated to be 3750W at 1MW proton beam. Therefore, a pressure control system should be required for the hydrogen system. A hybrid pressure control system, which consists of a heater and an accumulator, is prepared. The heater compensates a heat load of the nuclear heating, and the accumulator has a variable volume to absorb pressure fluctuation. The design of hybrid pressure control system required the estimation of hydrogen pressure behaves. An original computer code was developed to analyze such pressure behaviors in the various cases of nuclear heating change, for example proton beam on and off. Then the analysis result determined the capacity of the accumulator and the analysis indicated that the pressure change could be controlled within 0.15MPa by the designed hybrid control system.