声核中子测量的屏蔽设计  

Design for Shielding of Acoustic Neutrons Measurements

作　　者：李欣年[1] 朱晓娟[1] 范祥祥[1] 方晓明[1] 钱梦騄[2] 程茜[2] 

机构地区：[1]上海大学射线应用研究所,上海201800 [2]同济大学声学研究所,上海200092

出　　处：《原子能科学技术》2011年第11期1346-1351,共6页Atomic Energy Science and Technology

基　　金：国家自然科学基金重点资助项目(10434070);国家自然科学基金资助项目(10974145);上海市重点学科第三期资助项目(S30109)

摘　　要：通过测定声空化核效应实验室各测量点的中子注量率,了解实验室墙壁和地面对出射中子的散射,选定散射中子相对较弱的位置作为声核中子测量点。利用SHIELD程序模拟不同材料的中子屏蔽效果,选用4cm铁和20cm含硼石蜡组成屏蔽体,以降低中子本底。测定影屏蔽及影屏蔽结合BF3正比计数管环绕屏蔽两种方式下的散射修正因子Fs,提出以统计显著性增量S.S.I≥3/槡F s作为超声中子计数相对于非超声中子计数的增量ΔC是否具有统计意义的判据。The neutron fluence rates at different sites of the nuclear effect of acoustic cavitation（NEAC） lab were measured,and the site with less scattering neutrons was selected as the acoustic neutrons measuring point.Neutron shielding effects of different materials were simulated by SHIELD program.The 4 cm iron plate and 20 cm paraffin blocks were selected as optimum components for shadow shielding to reduce the neutron background.The scattering factor Fs of shadow shielding and shadow shielding combined with round shielding of BF3 proportional counter were measured.Besides,the statistically significant increase S.S.I≥3/Fs was proposed as the criterion of statistically significant difference between counts of neutrons with and without cavitation.

关 键 词：声空化核效应 散射中子 中子屏蔽 蒙特卡罗模拟 

分 类 号：TL81[核科学技术—核技术及应用]