激光-薄膜靶相互作用中前向超热电子的产额及能量转化效率

Yield and energy conversion efficiency of the forward hot electrons from laser-foil target

采用飞秒激光与薄膜靶相互作用测量了前向超热电子的分布和能谱。结果显示,前向超热电子主要集中在靶背法线方向附近区域发射,而超热电子的能谱呈双温类麦克斯韦分布。根据所测超热电子能谱和分布推算出前向超热电子总产额约1.23×108shot-1和前向超热电子的总能量约4.65×1011keV.shot-1,最后给出激光能量转化为前向超热电子能量的转化效率约5.72×10-4,这些结果与文献[17]的较好地一致。

The distribution and the energy spectrum of forward hot electrons produced by the interaction of fs-laser with foil target were measured. The results show that the forward hot electrons jet with a large angle width is mainly along the direction of rear normal of target; the energy spectrum of forward hot electrons is a Maxwellian-like distribution. The yield and energy of forward hot electrons is about 1.23×108shot-1 and 4.65×1011keV.shot-1, which were deduced from the distribution and the energy spectrum of forward hot electrons. The conversion efficiency of laser energy to forward hot electrons energy is about 5.72×10-4, which is better consistent with that from the reference [17].