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C decoupler with burn-up reduction aiming at 1-MW pulsed neutron sourceOi, Motoki; Teshigawara, Makoto; Harada, Masahide; Ikeda, Yujiro
Journal of Nuclear Science and Technology, 56(7), p.573 - 579, 2019/07
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)In pulsed neutron sources, a neutron absorber called decoupler is attached to the moderator to sharpen the neutron pulses for achieving good neutron energy resolutions. Cadmium and boron carbide (BC) are widely used as the decoupler materials. However, it is difficult to use BC in MW-class spallation neutron sources owing to high burn-up, which decreases cut-off energy and increase of helium gas swelling. To solve these issues, we introduce the concept of pre-decoupler to reduce neutron absorption in the BC decoupler, which is sandwiched by appropriate neutron absorption materials. Then, we study impacts of the pre-decouplers on BC decoupler in terms of burn-up by performing simplified model calculations. It is shown that neutron absorption in BC is reduced by 60% by using a Cd pre-decoupler without neutron intensity penalty. Moreover, helium gas swelling in BC is restrained to be one-third of the value when not using the pre-decoupler.
Seya, Michio; Hajima, Ryoichi*; Kureta, Masatoshi
Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu (CD-ROM), 10 Pages, 2017/02
Large size freight cargo containers are the most volunurable items from nuclear security points of view because of their large volume and weight of cargo inside for hiding heavily shielded objects. For strengthning nuclear security, secure detection of NMs in heavily shielded objects, and safe handling (dismatlement) of detected / suspicious objects for taking out of NMs, are essential. These require the following things, (1) Introduction of secure detection system of NMs, (2) Inspection of deteiled and interior structures of detected objects, (3) Rough chracterization of NMs (for nuclear bomb or RDD etc.) / Confirmation of existence of explosives etc.. By using information obtained by interior inspections, safe dismantlement of objects and taking NMs out are possible. In this papaer, we propose a combined system of X-ray scanning system with NRF-based NDD system using monochromatic 
-ray beam not only as a secure detection system of NMs but also interior inspection system (covering (1) and (2)). Also we propose active neutron NDA system using a D-T source for interior inspection of NM part (covering (3)).
Futakawa, Masatoshi
Nihon Genshiryoku Gakkai-Shi, 47(8), p.530 - 535, 2005/08
no abstracts in English
Kakurai, Kazuhisa; Endo, Yasuo
Kotai Butsuri, 40(4), p.239 - 250, 2005/04
no abstracts in English
Yamazaki, Dai; Ebisawa, Toru*
Hamon, 15(1), p.51 - 54, 2005/01
Neutron spin handling could be used for beam control and spectroscopy. Energy analysis could be performed with Drabkin energy filters, by which inelastic component with a 
, a 
or a 
could be extracted for all incident wavelength. Pulsed spin-flipper and polarization analyzer could be used as a neutron chopper (spin-flip chopper) whose opening time, number of windows and phase are controlled independently. It was demonstrated that S/N ratio can be enhanced up to 1.5 
10
by installing three spin-flip choppers in sequence.
Ikeda, Yujiro
Proceedings of ICANS-XVI, Volume 1, p.13 - 24, 2003/07
no abstracts in English
Watanabe, Noboru; Harada, Masahide; Kai, Tetsuya; Teshigawara, Makoto; Ikeda, Yujiro
Journal of Neutron Research, 11(1-2), p.13 - 23, 2003/03
no abstracts in English
Watanabe, Noboru
Reports on Progress in Physics, 66(3), p.339 - 381, 2003/03
Times Cited Count：48 Percentile：64.78(Physics, Multidisciplinary)no abstracts in English
Suzuya, Kentaro
Hamon, 13(1), p.51 - 55, 2003/01
With the arrival of the latest generation of synchrotron sources and the introduction of advanced insertion devices, the high-energy (E 
30 keV) X-ray diffraction technique has become feasible, leading to new approaches in the quantitative study of the structure of disordered materials. Recently, the high-energy X-ray diffraction data have been combined with neutron diffraction data from a pulsed source to provide more detailed and reliable structural information than that hitherto available. We have developed a two-axis diffractometer for glass, liquid and amorphous materials at the SPring-8 high-energy X-ray diffraction beamline BL04B2. Furthermore, we have succeeded to analyze the intermediate-range order of network forming glasses, SiO
, BO
, and GeO by the reverse Monte Carlo (RMC) modelling technique with special focused on the ring structures using both high-energy X-ray and neutron diffraction data.
Oyama, Kenji*; Ito, Shinichi*; Otomo, Toshiya*; Osakabe, Toyotaka; Suzuki, Junichi; Matsuda, Masaaki; Kuwahara, Keitaro*; Arai, Masatoshi*
Applied Physics A, 74(Suppl.1), p.S1598 - S1600, 2002/12
Times Cited Count：2 Percentile：11.51(Materials Science, Multidisciplinary)no abstracts in English
Kureta, Masatoshi
KEK Proceedings 2001-9, p.35 - 39, 2001/04
no abstracts in English
Watanabe, Noboru
JAERI-Conf 2001-002, p.42 - 60, 2001/03
no abstracts in English
Watanabe, Noboru
JAERI-Review 2000-031, 288 Pages, 2001/01
JAERI-Review-2000-031.pdf:16.17MB
no abstracts in English
Watanabe, Noboru; Teshigawara, Makoto; Kai, Tetsuya; Harada, Masahide; Sakata, Hideaki*; Ikeda, Yujiro; Kaminaga, Masanori; Hino, Ryutaro; Oyama, Yukio
Proceedings of 8th International Conference on Nuclear Engineering (ICONE-8) (CD-ROM), p.12 - 0, 2000/00
no abstracts in English
Watanabe, Noboru*; Teshigawara, Makoto*; Takada, Hiroshi; Nakashima, Hiroshi; Oyama, Yukio; *; Kai, Tetsuya; Ikeda, Yujiro; Kosako, Kazuaki*
Proc. of 14th Meeting of the Int. Collaboration on Advanced Neutron Sources (ICANS-14), 2, p.728 - 742, 1998/00
no abstracts in English
*
JAERI-Research 97-040, 23 Pages, 1997/06
JAERI-Research-97-040.pdf:0.73MB
no abstracts in English
Mishima, Kaichiro*; Hibiki, Takashi*; Fujine, Shigenori*; Yoneda, Kenji*; Tsuruno, Akira; Matsubayashi, Masahito; Sobajima, Makoto
Nihon Kikai Gakkai Rombunshu, B, 61(591), p.161 - 168, 1995/11
no abstracts in English
Nuclear Instruments and Methods in Physics Research A, 253, p.43 - 46, 1986/00
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)no abstracts in English
JAERI-M 7753, 176 Pages, 1978/08
no abstracts in English
