摘要
利用加速器提供的非全裸重离子束 (q=1 - 4)轰击氦、氖和氩原子 ,研究了由非全裸离子引起原子多重电离的有效电荷效应和电荷交换效应 .提出用一个有效电荷来等价描述非全裸入射离子对靶原子的作用 ,将描述全裸离子 -原子碰撞过程的物理模型推广到处理非全裸离子 -原子碰撞过程 ,采用轨道贯穿模型对有效电荷的内在物理机制进行了解释 ,提出一种新的理论方法将多重电离中俄歇过程的贡献予以扣除 .通过研究发现 ,扣除俄歇过程贡献后 ,多重电离截面随入射离子q/
The partially stripped C q+ , O q+ and F q+ ions (q=1-4) delivered by a 2×1.7 MV tandem accelerator were employed to bombard He, Ne and Ar targets. The cross section ratios of multiple ionization to single ionization were measured for different collision systems by using time of flight technique. The effective charge effects and charge exchange processes were studied. By using an effective charge q eff , the multiple ionization processes induced by partially stripped ions could be considered to be equal to the those of the fully stripped ion, and the theoretical model developed for the fully stripped ion atom collisions could be used to the partially stripped ion atom collisions. The effective charge effect was explained by using orbital interpenetration. For the multiple ionization of multi electron targets, a new method was proposed and presented to exclude the contribution of the Auger transition to the total multiple ionization. It is found that the cross section ratios of the pure multiple ionization (excluding Auger process) to those of the single ionization are in agreement with the q/v laws predicted by the multi step model.
出处
《原子核物理评论》
CAS
CSCD
2000年第3期179-182,共4页
Nuclear Physics Review
基金
国家自然科学基金资助项目!(19604004)
核工业基金资助项目
中国博士后基金资助项目
