摘要
For Li^＋ and Na^＋ ions scattered from high work function metal surfaces, efficient neutralization is observed, and it cannot be explained by the conventional free electron model. In order to explain these experimental data, we investigate the velocity-dependent neutral fraction with the modified Brako–Newns（BN） model. The calculated results are in agreement with the experimental data. We find that the parallel velocity effect plays an important role in neutralizing the Li^＋ and Na^＋ ions for large angle scattering. The nonmonotonic velocity behavior of neutral fraction is strongly related to the distance-dependent coupling strength between the atomic level and metal states.
For Li^＋ and Na^＋ ions scattered from high work function metal surfaces, efficient neutralization is observed, and it cannot be explained by the conventional free electron model. In order to explain these experimental data, we investigate the velocity-dependent neutral fraction with the modified Brako–Newns（BN） model. The calculated results are in agreement with the experimental data. We find that the parallel velocity effect plays an important role in neutralizing the Li^＋ and Na^＋ ions for large angle scattering. The nonmonotonic velocity behavior of neutral fraction is strongly related to the distance-dependent coupling strength between the atomic level and metal states.
基金
supported by the National Natural Science Foundation of China(Grant Nos.11405078 and 11474140)
the Fundamental Research Funds for the Central Universities,China(Grant Nos.lzujbky-2014-169 and lzujbky-2015-244)
sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars
the State Education Ministry,and the National Students’ Innovation and Entrepreneurship Training Program(Grant Nos.201410730069 and 201510730078)
