摘要
正电子湮没技术能够快速、精确、无损地对材料内部微观缺陷进行探测.将慢正电子束多普勒展宽能谱仪引入实验教学,选取核聚变堆壁材料金属钨为测试对象,调节正电子束能量,采集正电子在钨中湮没产生的γ光子信号.通过对γ光子多普勒展宽能谱进行处理分析,获得辐照前后样品近表面空位型缺陷数量随深度的变化规律,使学生掌握基于正电子湮没技术研究材料缺陷行为的实验技能.
Positron annihilation techniques can detect microscopic defects in materials accurately and nondestructively.Doppler broadening spectrometer with an energy-variable slow positron beam was introduced into experimental teaching.Tungsten,aplasma-facing material in fusion reactors,was chosen as the test object.By adjusting the acceleration voltage of the positron beam,and collecting the signal of annihilation photons when positrons annihilate in tungsten,Doppler broadening of photon energy spectra corresponding to different depths was measured.Through the analysis of experimental data,the depth profiles of vacancy-type defects in the near surface of tungsten before and after irradiation could be obtained.Consequently,students could master the experimental skills in studying defects behavior in materials based on positron annihilation techniques.
作者
袁悦
王汉卿
王诗维
程龙
张鹏
曹兴忠
金硕
吕广宏
YUAN Yue;WANG Han-qing;WANG Shi-wei;CHENG Long;ZHANG Peng;CAO Xing-zhong;JIN Shuo;LU Guang-hong(School of Physics,Beihang University,Beijing 100191,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China)
出处
《物理实验》
2022年第3期17-21,共5页
Physics Experimentation
基金
高等学校力学课程教改项目
北京航空航天大学2019-2022年教育教学改革培育项目。
关键词
正电子湮没技术
γ光子
多普勒展宽谱
空位型缺陷
深度分布
positron annihilation techniques
γphoton
Doppler broadening spectroscopy
vacan-cy-type defect
depth profile
