基于CR-39的核径迹形态估算入射质子能量和角度方法初探  

Preliminary study on estimating the energy and angle of incident protons based on the nuclear track morphology on CR-39

作　　者：李志灵 陈波[1] 卓维海[1] 张伟[2] Li Zhiling;Chen Bo;Zhuo Weihai;Zhang Wei(Institute of Radiation Medicine,Fudan University,Shanghai 200032,China;Key Laboratory of Nuclear Physics and Ion-beam Application(MOE),Fudan University,Shanghai 200433,China)

机构地区：[1]复旦大学放射医学研究所,上海200032 [2]复旦大学核物理和离子束应用教育部重点实验室,上海200433

出　　处：《中华放射医学与防护杂志》2020年第5期392-396,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：国家重点研发计划资助(2016YFF0200804);国家自然科学基金(11775054)。

摘　　要：目的探究基于CR-39上的核径迹形态来估算入射质子的能量和角度的方法。方法用不同入射能量和角度的质子照射CR-39,经化学蚀刻后分别用原子力显微镜和光学显微镜读取核径迹的形态,通过对核径迹二维形态的定量分析,尝试建立利用核径迹形态来判别入射粒子能量和角度的方法。结果随着入射质子能量的增加,核径迹变小变浅;在垂直入射情况下,径迹开口接近于圆形;随着入射角度的增加,径迹开口逐渐呈椭圆形变化。圆形核径迹的直径、椭圆形核径迹的短轴或等效直径与入射质子的能量均呈显著的指数衰减关系(E=Ae-B x)。用核径迹的直径(或等效直径)和短轴来拟合的系数(A、B)分别为:(15.763,0.305)和(15.886,0.320)。入射粒子的角度与椭圆形核径迹的长短轴之比也存在相对固定的定量关系,对10°和20°入射的质子,核径迹长短轴之比的均值分别为1.10~1.15和1.35~1.37。结论入射粒子的能量可以通过CR-39上形成核径迹的直径或短轴长度来估算;入射粒子的角度可以用核径迹的长短轴之比来估算。Objective To explore the method for estimating the energy and angle of incident protons based on the nuclear track morphology on CR-39.Methods The CR-39 was irradiated with different energies and angles of incident protons and the morphology of nuclear tracks was scanned and read out by both the atomic force microscope and optical microscope after chemical etching.Through out quantitative analyses of the two-dimensional morphology of the nuclear tracks,an attempt was made to establish the method for estimating the energy and angle of incident particles.Results As the increase of incident proton energy,the nuclear track became smaller and shallower.In the case of vertical incidence,the track opening was close to a circle.As the incident angle increases,the track opening gradually changed into an ellipse shape.The diameter of the circular nuclear track and the minor axis or the equivalent diameter of the elliptical nuclear track both decrease exponentially(E=Ae-B x)with the increase of the incident energy of protons.The fitting coefficients A and B were 15.763 and 0.305,and 15.886 and 0.320 by using the diameter/equivalent diameter and the minor axis of tracks.There also existed a relatively fixed quantitative relationship between the angle of the incident particle and the ratios of the major and minor axes of the elliptical nuclear track.For protons incident at 10°and 20°,the average ratios of the major and minor axes of the nuclear track were 1.10-1.15 and 1.35-1.37,respectively.Conclusions Based on the diameter or minor axis of the nuclear track formed on CR-39,the energy of incident particles can be estimated,and the angle of incident particles can also be estimated by using the ratio of the major and minor axes of the nuclear track.

关 键 词：质子 CR-39 入射能量 入射角度 

分 类 号：R730.55[医药卫生—肿瘤]