Study of the background in the experiments of inner-shell ionization of atoms by positron impact
One of main difficulties in the experiments of inner-shell ionization of atoms by positron impact near threshold energy region is the relatively high low-energy background,which is caused by the deposited part of energy in semi-conductor X-ray detectors of 0.511 MeV γ rays that are produced by positron annihilations in targets and target chamber.In this paper,by using the Monte Carlo method,we simulated the backgrounds for the X-ray detectors with the sensitive layer thickness of 0.3 mm and 3 mm in the case of 0.511 MeV γ rays impacting vertically on a Ti plate of 0.2 mm in thickness,and compared the simulation results with the experimental observations of the other research group and our own.Moreover,we also simulated the backgrounds for a simplified experimental setup in the case of 20 keV positrons impacting vertically on a thick Ti target and observed that the backgrounds for the X-ray detectors with the sensitive layer thickness of 0.3 mm and 3 mm,are very similar.
positron atomic ionization by positron impact Monte Carlo simulation
AN Zhu(安竹) LIU Man-Tian(刘慢天) ZHU Jing-Jun(朱敬军)
Institute of Nuclear Science and Technology,Key Laboratory for Radiation Physics and Technology of Education Ministry,Sichuan University,Chengdu 610064,China
国际会议
The 13th National Nuclear Physics Conference of China(第十三届全国核物理大会暨第八届会员代表大会)
兰州
英文
270-273
2007-08-22（万方平台首次上网日期，不代表论文的发表时间）