Bragg峰能区Xe^(20+)与不同靶作用产生的X射线

X-rays produced by interaction of Xe^(20+) with different targets in Bragg peak energy region

依托兰州重离子加速器国家实验室320 kV高电荷态离子综合研究平台,测量了动能为6.0 MeV的Xe^(20+)离子与V,Fe,Ni,Cu,Zn靶表面作用产生的特征X射线谱,分析了能量为1.60 keV的X射线的产生机制,并利用经典过垒模型计算了Xe^(20+)与不同靶作用时第一代空心原子在上表面的存在时间.结果表明:对于没有初始M空穴的Xe^(20+)离子与不同靶相互作用时,实验中没有观察到Xe的Mα X射线,而观察到了能量为Xe的Mα X射线的两倍的X射线,称此线为Xe的Mαα X射线,认为其是由Xe在靶的上表面的双电子单光子过程产生的.

The inner shell process produced by the collision of highly charged ion with medium atoms near the Bragg peak is an important frontier area of atomic physics under extreme conditions such as celestial plasmas and controlled nuclear fusion plasmas.Because of the special complexity of the inner shell process produced by the collision of ions with atoms in the Bragg peak energy region and the relevant experimental research is less,limited by the experimental conditions,there remain some interesting and unanswered questions.We report the experimental data of X-ray spectra produced by the impact of Xe^(20+) with 6.0 MeV kinetic energy on V,Fe,Ni,Cu,and Zn surface in the National Laboratory of Heavy Ion Research Facility in Lanzhou,China.The generation mechanism of X-ray with energy of 1.60 keV is analyzed.The results show that when Xe^(20+) without initial holes interacts with different targets,the Ma X-ray of Xe is not observed,but X-ray with energy twice as great as that of Xe Ma X-ray is observed in the experiment,which is called Xe Maa X-ray and considered to be generated by the two-electron-one-photon process of Xe on the upper surface of the target.The existence time of the first-generation hollow atoms on the upper surface is calculated by using the classical over-barrier model when Xe^(20+) interacts with different targets,which is consistent with the variation of Maa X-ray yield with the atomic number of target,therefore it is further proved that Maa X-ray is formed by the two-electron one-photon process of Xe on the upper surface of the target.Of course,this conclusion needs further analyzing and verifying with more experimental data.