飞秒激光与Cu靶和CH靶相互作用产生的快电子能谱实验研究

摘要

为了研究靶材料对快电子能量分布的影响，采用电子谱仪测量了飞秒激光与Cu和CH靶相互作用中在靶前和靶后产生的快电子能谱。结果显示，在靶前Cu和CH靶的快电子能谱相似，反应了快电子发射对靶材料的依赖性较弱；在靶后Cu和CH靶的快电子能谱具有明显的差异，说明电子的输运过程与靶材料密切相关。冷电子环流以及自生磁场是导致 Cu 靶快电子能谱“软化”的原因，而对于 CH 靶麦克斯韦分布的快电子能谱主要由碰撞机制决定。%In order to investigate the effect of target’s material on fast electron energy distribution, the energy distribution of fast electrons from the front and the rear of Cu and CH targets have been measured during the interaction of femtosecond laser-foil targets. The results show that the fast electron spectrums from the front of Cu and CH targets are similar, which show energy distribution of fast electrons depends very little on material of targets. The fast electron spectrums from the rear of Cu and CH targets are obviously dissimilar, which indicate a mighty effect of target material on fast electron transport. The fast electron spectrums from the Cu target is“soften”, which is due to electron recirculation and self-magnetic field produced by electrons transported in the target. The fast electron spectrums from the CH target is a Maxwellian distribution, which is due to collision effect when electrons transport in the target.