摘要:
在中能区测量了Cq+(q=1—4)与He,Ne,Ar气体原子碰撞的电子损失截面,计算分析了入射离子损失两个电子与一个电子的总截面比R21.单反应道分析无法完全解释所有实验结果,必须同时考虑入射离子的电子损失、电子俘获和靶原子电离各种出射道间的耦合作用.对于不同靶原子的碰撞,入射离子损失一个电子和两个电子的速度阈值可以由屏蔽和反屏蔽理论解释.然而,该理论不能完全解释截面比R21随入射离子速度变化的实验结果.随着碰撞速度的提高,靶的有效电荷增加,碰撞参数趋小.由Cq+(q=1—4)与Ne,Ar靶原子碰撞的电子损失总截面比R21随速度变化规律和幅度大致相同可以推测Ne与Ar靶原子的有效电荷相当,而He靶原子的有效电荷比前两者小.另外,根据实验结果还分析了入射离子损失电子间的关联.
Abstract:
Electron-loss cross sections in Cq+(q=1—4)collisions with He,Ne,Ar are measured in the intermediate-velocity regime,and the ratio of the two-electron-loss cross section to the one-electrom-loss cross section,R21,are calculated.It is shown that a single-channel analysis is not sufficient to explain the results,and that projectile electron loss,electron capture by the projectile,and target ionization must be considered together to interpreter the data.The screening and antiscreening theory can annalyse the threshold velocity,but cannot totally explain the data of R21 with velocity increasing.The effective charge of target increases with velocity increasing.Ne and Ar have the same effective charges in the velocity regime,but He has a smaller one at the same velocity.The correlation between loss electrons is also analyzed.