摘要
介绍了一种放射性样品检测的γ射线自吸收校正方法。对聚乙烯为介质的均匀体源样品进行了无损透射测量和发射测量实验,并使用MCNP程序对透射测量和发射测量过程进行模拟,由透射测量得到样品对多个能量γ射线的线衰减系数,拟合得到线衰减系数随能量变化的特征方程,从而获取发射γ射线在样品中的线衰减系数以及自吸收校正因子,结合发射γ射线的探测效率,计算得到校正后的样品活度。验证实验表明:样品校正活度相对误差均在6%以内。
A gamma - ray self - absorption correction method of radioactive sample measurement is described. Non - destructive transmission and emission measurement are experimented and simulated by MCNP program for uniform density radioactive polyethylene samples. Characteristic equation of gamma - ray linear attenuation co- efficients of different energy is obtained from transmission measurement. Gamma - ray linear attenuation coeffi- cients of emission measurement are obtained from characteristic equation, and then self - absorption correction factors can be got. Samples＇ radioactivities are calculated by self - absorption correction method when gamma - ray detection efficiency is obtained by experimental measurement. The results show that related deviation of cor- rected radioactivity of samples are less than 6%.
出处
《核电子学与探测技术》
CAS
北大核心
2015年第9期936-939,共4页
Nuclear Electronics & Detection Technology
基金
西南科技大学研究生创新基金(15ycx001)
国家自然科学基金(41374130)资助
关键词
均匀体源
自吸收校正
蒙特卡罗模拟
HPGE探测器
uniform density radioactive sample
self - attenuation correction
MCNP
HPGe detector
