高频强激光场中H-电离特性理论研究

高频强激光场中高价负离子（比如H-,H2-,He-,He2-等等）的稳定存在虽然在理论上早已得到得到证明，但在实验上至今没有被直接验证。为了探索可行的实验验证方案，通过以高频强场中的负一价氢离子H-为例，采用相空间平均法，详细研究了其在外加激光场中的电离率及光电子角分布情况。研究发现 的电离率比氢原子高，并且不存在氢原子在较强激光场中的电离抑制现象。另外随着激光场强度的增大和激光频率的减小，电子角分布与H-在高频场直接卸载后电子角分布的差别也增大。这些结果为将来在实验上验证高频强场中高价负离子的存在性提供了很好的理论依据。

Ionization characteristics of H- in intense high-frequency laser fields

The stability of the multiply charged negative ions in the high-frequency inense laser fields, such as H-,H2-,He-,He2-, has been proved in theory for a long time. But no experimental verification has ever been made until now due to various technological challenges. To pave the way for the future experimental test, in this article, by using H- as an example, we study in details its ionization rate and the angular distribution of ionized electron with the method of classical phase space ensemble average. It is found that the overall ionization rate of H- is higher than that of the hydrogen atom and no ionization suppression exits in ultra-intense field. And for high-intensity or low-frequency laser fields, the angular distribution of the ionized electrons is quite different from the electron distribution of when the laser field is switched off abruptly.