Papers by Keyword: Moderator

Paper TitlePage

Authors: Kenji Kikuchi, Makoto Teshigawara, Masahide Harada, Shigeru Saito, Fujio Maekawa, Masatoshi Futakawa, Toru Ishigaki
Abstract: A sharp pulsed-neutron beam, which has narrow width and large attenuation, will enhance ability to separate peak position diffracted from crystal structure in time-of-flight measurement method. Traditional technique to satisfy the request above is to use Boron for decoupling higher cut-off energy. Disadvantage, however, will be an excess formation of He bubbles and large heat deposition in the materials as a result of (n,α) reaction, particularly in a MW class of neutron source. Alternative is to use a material combination of Ag-In-Cd, which has different energies for resonance absorption and often used in the control rod of pressurized water reactors with cladding stainless steel. For application of this material to pulsed-neutron source a challenge is to make sandwiches structure with Al alloy because a moderator is made of this material from points of views of heat removing. Technically hot isostatic pressing was a choice and devoted to realize a bonding strength through R&Ds. Final product was set up to MLF /J-PARC and a successful resolution was observed in a powder diffractometer.
Authors: P. Willutzki, P. Sperr, D.T. Britton, Gottfried Kögel, R. Steindl, Werner Triftshäuser
Authors: P. Willutzki, J. Störmer, Gottfried Kögel, Peter Sperr, D.T. Britton, R. Steindl, Werner Triftshäuser
Authors: M. Irako, M. Chiba, M. Fukusima, R. Hamatsu, Masataka Hirose, T. Hirose, H. Iijima, T. Kumita, N.C. Mazumdar, M. Washio
Authors: Marc H. Weber, Christoph G. Fischer, Kiminori Sato, Kelvin G. Lynn
Authors: Valery A. Varlachev, Alexey V. Golovatsky, Evgeny G. Emets, Yana A. Butko
Abstract: The neutron transmutation doping (NTD) of silicon is usually used for producing different electronic devices like thyristors, VLSI, detectors, etc. This article focuses on the formation of the radiation field to create the technology for silicon NTD implementing a pool-type nuclear reactor. The works includes the analytical consideration of the conditions for achieving the high radial irradiation uniformity of silicon ingots.
Authors: Ryoichi Suzuki, Toshiyuki Ohdaira, Tomohisa Mikado, Akira Uedono, Hideaki Ohgaki, T. Yamazaki, Shoichiro Tanigawa
Authors: Qing Shan, Qun Li, Can Cheng, Wen Bao Jia, Da Qian Hei, Yong Sheng Ling
Abstract: An online coal measurement system, which is based on the prompt gamma neutron activation analysis (PGNAA) technology and uses a D-T neutron generator, is studied in this work. To improve the analytical precision of the element in coal, the original moderator is optimized. The standards of the optimization are (1) the neutron flux increase 50% after moderation; (2) the proportion of thermal and middle-energy neutron and fast neutron is nearly equal to 1:1. Using Monte Carlo method, the moderator has been optimized by adding the uranium238 to the original moderator, which consists of high density polyethylene (HDPE). The simulation results show that the optimization standards can be basically satisfied when the thickness of the uranium238 and HDPE are 4cm and 1cm respectively. On this basis, preliminary study on introducing the channel to moderator is carried out. The preliminary results show that the channel can improve the total neutron flux. But also, it will decrease the proportion of thermal and middle-energy neutron and fast neutron.
Authors: Roberto S. Brusa, Marco Duarte Naia, E. Galvanetto, Paolo Scardi, Antonio Zecca
Showing 1 to 10 of 10 Paper Titles