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Shibata, Kaoru; Tamura, Itaru; Soyama, Kazuhiko; Arai, Masatoshi; Middendorf, H. D.*; Niimura, Nobuo
Proceedings of ICANS-XVI, Volume 1, p.351 - 354, 2003/07
In this research report we describe the design of DYANA, a new neutron spectrometer dedicated for biology, biomaterials, and related soft-matter studies, which will be installed in the material and life science experimental facility project at the JAERI Tokai establishment. The DYANA spectrometer is an indirect-geometry crystal-analyzer instrument and its energy and momentum transfer range are from several 10
eV to several meV and from 0.1
to several , respectively. These specifications will become possible to do the study of protein dynamics analysis.
Nakamura, Tatsuya; Masaoka, Sei; Yamagishi, Hideshi; Soyama, Kazuhiko; Aizawa, Kazuya
Proceedings of ICANS-XVI, Volume 1, p.441 - 446, 2003/07
Development of a Micro-Strip Gas Chamber(MSGC) in JAERI is presented. The performances we aim at are counting rate 
10
, position resolution 
1
, detection efficiency 60% at thermal neutron and good n/gamma discrimination. Our two-dimensional gas detector consists of a micro strip plate printed on a polyimide substrate and a high pressure gas chamber which has all the signal lines are directly taken out (256ch individual readout) and withstands the pressure of 10bar 
. The individual signal readout opens the way to realize high counting rate and high position resolution at the same time. We carried out range measurements of secondary particles to confirm the range measuring power of the MSGC with that read out method. The measured ranges in the gas of 3bar helium mixed with 
ethane is 3mm, 9.5mm for triton and proton, respectively. Those values are well agreed with theoretical estimation and we could show the feasibility of the precise measurement of the ranges by the MSGC.
Tamura, Itaru; Aizawa, Kazuya; Harada, Masahide; Shibata, Kaoru; Maekawa, Fujio; Soyama, Kazuhiko; Arai, Masatoshi
Proceedings of ICANS-XVI, Volume 1, p.529 - 539, 2003/07
Moderator components of the McStas code have been created for the design of the spectrometers of JSNS. Three cryogenic moderators are adopted in JSNS, One is a coupled H
moderator for high intensity experiments and other two are decoupled H with poisoned or unpoisoned for high resolution moderators. Monte Carlo simulations have turned out to be useful for design of neutron scattering instruments with high complexity. The software package McStas is selected for its own flexibility. Since the characteristics of neutron beams generated from moderators make influence on the performance of pulse neutron spectrometers, it is important to perform the simulation with neutron source component written precisely. Both Energy dependence of neutron spectrum and time structure of neutrons were calculated using NMTC/JAERI97 and MCNP4a codes.The simulation parameters, which describe the pulse shape as a function of time, are optimized. The creation of neutron source components viewed to coupled H moderator and viewed to decoupled H moderator of JSNS are reported.
Kaminaga, Masanori; Haga, Katsuhiro; Kinoshita, Hidetaka; Torii, Yoshikatsu; Hino, Ryutaro; Ikeda, Yujiro
Proceedings of ICANS-XVI, Volume 1, p.125 - 133, 2003/07
no abstracts in English
Ikeda, Yujiro
Proceedings of ICANS-XVI, Volume 1, p.13 - 24, 2003/07
no abstracts in English
Yamazaki, Dai; Soyama, Kazuhiko; Ebisawa, Toru*; Tamura, Itaru; Tasaki, Seiji*
Proceedings of ICANS-XVI, Volume 1, p.407 - 415, 2003/06
Drabkin energy filters extract neutrons of required wavelength using spatial neutron spin resonance. If they are applied to pulsed neutrons, they could sharpen pulse width and cut tail neutrons without reducing band-width or peak-intensity. Shaping of J-PARC coupled-moderator pulse by a Drabkin energy filter was simulated. In the simulation, discrete field gradient to Bx is introduced and total field B is varied in accordance with the dominant wavelength at each moment at the filter position. The results suggest that about 90 % or more of tail neutrons from coupled moderator are cut and a fliter with fields of 200 periods could reduce pulse width up to that of decoupled moderator. Effects of fluctuations of width of each half period were studied and it was found that fluctuation within 
1 % are tolerable for a flipper with field of 100 or 200 periods.