NaI(Tl)探测器对23.8MeV γ射线的效率刻度方法  

Efficiency Calibration Method of NaI(Tl) Detector in 23.8 MeV for γ-Ray

作　　者：苏晓斌[1] 刘洋[2] 侯龙[1] 王朝辉[1] 王琦[1] 

机构地区：[1]中国原子能科学研究院核数据重点实验室,北京102413 [2]中国原子能科学研究院反应堆物理研究室,北京102413

出　　处：《原子核物理评论》2015年第4期440-445,共6页Nuclear Physics Review

基　　金：中国核工业集团公司核数据专项基金资助(4160303)~~

摘　　要：低能D(d,γ)~4He辐射俘获反应截面的研究在聚变领域和天体物理等领域中起到非常重要的作用。由于受到标准γ源能量的制约,在研究D(d,γ)~4He反应产生的23.8 MeV高能γ射线产额实验过程中不能用标准源进行效率刻度。采用实验测量与计算相结合的方法实现NaI(Tl)探测器对23.8 MeVγ射线的效率刻度是比较成熟可靠的。针对高能γ射线的产额低、本底大的情况,实验采用一个大型NaI(Tl)反康谱仪进行测量,以提高探测效率。NaI(Tl)探测器的效率,独特地采用了包括全能峰、单逃逸峰和双逃逸峰在内的效率来计算,经MCNP-4C程序模拟计算,结合实验测量的19F(p,αγ)^(16)O反应产生的6.13 MeVγ射线探测效率推算出该NaI(Tl)探测器在23.8 MeV的效率为(2.23±0.34)‰。该方法对研究高能γ射线效率刻度具有重要的参考价值。In the study of D（d,γ）^4He radiative capture reactions research, which is very important for fusion and astrophysics, the efficiency calibration of the detector is necessary. Due to the restriction on energy of the standard γ source, the efficiency calibration of high-energy γ-rays can not be calibrated by a standard source. In this paper, the method combining the experimental measurements and calculations for the efficiency calibrations of high energy γ rays is given in the experiment of 6.13 MeV γ rays efficiency calibration using NaI（Tl） detector,the efficiency curve of which is calculated by MCNP-4C and corrected experimentally. The efficiency includes the total energy peak, single escape and double escape peaks. In this case, the detection efficiency of 23.8 MeV γray is obtained as（2.23 ± 0.34）‰, The method provides a reference to high energy γ ray efficiency calibration.

关 键 词：NAI(TL)探测器 能量 Γ射线 效率刻度 MCNP-4C 

分 类 号：P631.83[天文地球—地质矿产勘探]