关键词: X射线/
产生截面/
高能脉冲束
English Abstract
K-shell X-ray emission from high energy pulsed C6+ ion beam impacting on Ni target
Mei Ce-Xiang1,2,Zhang Xiao-An1,3,
Zhou Xian-Ming3,
Zhao Yong-Tao2,3,
Ren Jie-Ru2,
Wang Xing2,
Lei Yu3,
Sun Yuan-Bo3,
Cheng Rei3,
Xu Ge3,
Zeng Li-Xia1,2
1.Ion beam & Optical Physical Joint Laboratory of Xianyang Normal University and Institute of Modern Physics, Chinese Academy of Sciences, Xianyang 712000, China;
2.School of Science, Xi'an Jiaotong University, Xi'an 710049, China;
3.Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant Nos. 11605147, 11505248) and the Scientific Research Program Funded by Shaanxi Provincial Education Department, China (Grant No. 15JK1793).Received Date:30 March 2017
Accepted Date:05 May 2017
Published Online:05 July 2017
Abstract:Accurate measurement of the ionization cross section of the target atom induced by collision between ions and atoms is of great significance for studying the atomic shell process and establishing a suitable theoretical model. The experimental data and the theoretical models mostly concentrate on the cases in the low energy region at present. Only a few experimental data of high energy region are reported due to the limitation of experimental conditions. Which theory is more suitable to describe the ionization cross section of the inner shell of the target atom caused by the high energy heavy ions, is necessarily studied experimentally. The C6+ ions provided by the Heavy Ion Research Facility in Lanzhou Electron Cooling Storage Ring, are used to bombard the Ni target, in which the K-shell X-ray of Ni is measured. The incident energies of C6+ ions are 165, 300, 350 and 430 MeV/u respectively. Through analyzing the intensity ratio of K/K X-ray of Ni, it is found that the influence of incident energy on the intensity ratio of K/K X-ray is not obvious. The intensity ratios of this experiment are greater than the experimental values of incident proton and the calculated values based on the Hartree-Slater theory, which may be caused by the multiple-ionization of the L shell. The production cross sections of Ni K-shell X-ray are calculated by the binary encounter approximation (BEA) model, the plane wave Born approximation (PWBA) model and the energy-loss coulomb-repulsion perturbed-stationary-state relativistic (ECPSSR) theory respectively, which are compared with the experimental results in this paper. It is found that the experimental cross section increases with the increasing incident energy, which is consistent with the trend of BEA model estimation, but the experimental value is obviously lower than the theoretical value. We think that BEA model needs to be modified when describing the ionization process in the high energy region.
Keywords: X-ray/
production cross section/
high energy pulsed beam
