中国物理B ›› 2005, Vol. 14 ›› Issue (3): 500-504.doi: 10.1088/1009-1963/14/3/012

• NUCLEAR PHYSICS • 上一篇    下一篇

Neutronic studies of the coupled moderators for spallation neutron sources

殷雯, 梁九卿   

  1. Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
  • 收稿日期:2004-08-09 出版日期:2005-03-02 发布日期:2005-03-02

Neutronic studies of the coupled moderators for spallation neutron sources

Yin Wen (殷雯), Liang Jiu-Qing (梁九卿)   

  1. Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
  • Received:2004-08-09 Online:2005-03-02 Published:2005-03-02

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摘要： We investigate the neutronic performance of coupled moderators to be implemented in spallation neutron sources by Monte-Carlo simulation and give the slow neutron spectra for the cold and thermal moderators. CH4 moderator can provide slow neutrons with highly desirable characteristics and will be used in low-power spallation neutron sources. The slow neutron intensity extracted from different angles has been calculated. The capability of moderation of liquid H2 is lower than H2O and liquid CH4 due to lower atomic number density of hydrogen but we can compensate for this disadvantage by using a premoderator. The H2O premoderator of 2cm thickness can reduce the heat deposition in the cold moderator by about 33% without spoiling the neutron pulse.

Abstract: We investigate the neutronic performance of coupled moderators to be implemented in spallation neutron sources by Monte-Carlo simulation and give the slow neutron spectra for the cold and thermal moderators. CH4 moderator can provide slow neutrons with highly desirable characteristics and will be used in low-power spallation neutron sources. The slow neutron intensity extracted from different angles has been calculated. The capability of moderation of liquid H2 is lower than H2O and liquid CH4 due to lower atomic number density of hydrogen but we can compensate for this disadvantage by using a premoderator. The H2O premoderator of 2cm thickness can reduce the heat deposition in the cold moderator by about 33% without spoiling the neutron pulse.

Key words: neutronic studies, spallation neutron source, moderator

中图分类号:  (Neutron sources)

  • 29.25.Dz
28.41.Pa (Moderators) 24.10.Lx (Monte Carlo simulations (including hadron and parton cascades and string breaking models)) 21.60.Ka (Monte Carlo models) 25.40.Sc (Spallation reactions) 29.30.Hs (Neutron spectroscopy)