De Pangher长计数器等效中心测量及分析  

Measuring and Analysis for Equivalent Center of the De Pangher Long Counter

作　　者：艾杰[1] 范锐锋[1] 马景芳[1] 

机构地区：[1]中国工程物理研究院流体物理研究所,绵阳621900

出　　处：《核电子学与探测技术》2014年第11期1287-1290,1296,共5页Nuclear Electronics & Detection Technology

摘　　要：为了准确测量长计数器到源的距离,需要确定长计数器等效中心的位置。对单能中子源,在等效中心处,长计数器可被视为＂点＂探测器,其探测效率与其工作距离成平方反比关系。如果事先知道长计数器在不同工作距离下的探测效率,则可以利用该平方反比关系确定长计数器等效中心的位置。利用加速器中子源,分别在0.144 Me V、0.565 Me V、1.2 Me V、2.5 Me V、5.1 Me V以及14.8 Me V等6个能量点刻度了De Pangher长计数器距靶心不同距离处的探测效率,利用平方反比关系得到长计数器在各能量下的等效中心位置。由实验数据拟合出长计数器等效中心到其前端面距离r0与中子能量En的关系曲线,结果表明在0.144-14.8 Me V范围内,r0与中子能量的自然对数近似呈线性关系。In order to accurately measure the distance between a long counter and the source,the position of the long counter＇s equivalent center should be determined. For single- energy neutron source,the long counter can be regarded as a ＂ point ＂ detector at its equivalent center,whose detection efficiency is in the inverse square relationship with working distance. If the detection efficiency of the long counter at different distances is known,then the equivalent center can be determined using the inverse square relationship. With the accelerator neutron source,detection efficiency of a De Pangher long counter at different distances to the source is calibrated. The neutron energy changes at 0. 144 Me V、0. 565 Me V、1. 2 Me V、2. 5 Me V、5. 1 Me V and 14. 8 Me V during the calibration. Based on these efficiency,the distance（ r0） from the equivalent center to the long counter＇s front face is got using the inverse square relationship. Curve of the r0- Enis plotted and the result shows that,at the range of [0. 144,14. 8]Me V,the equivalent center of the De Pangher long counter is proportional to the nature logarithm of the neutron energy.

关 键 词：长计数器 中子 等效中心 参考点 慢化 

分 类 号：TL816.3[核科学技术—核技术及应用]