椭圆偏振激光脉冲驱动的氩原子非次序双电离  

The nonsequential double ionization of argon atoms with elliptically polarized laser pulse

作　　者：余本海[1] 李盈傧[1] 汤清彬[1] 

机构地区：[1]信阳师范学院物理电子工程学院,信阳464000

出　　处：《物理学报》2012年第20期213-219,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11005088;11047145);河南省科技计划(批准号:102300410241;112300410021);河南省教育厅自然科学研究计划(批准号:2009A140006;2011B140018)资助的课题~~

摘　　要：利用经典系综模型研究了椭圆偏振激光脉冲驱动的氩原子非次序双电离.计算结果表明,非次序双电离产率随着椭偏率的增大而减小;双电离得到的电子对在激光偏振平面长轴方向的末态关联动量谱呈现正关联,在激光偏振平面短轴方向的末态关联动量谱呈现反关联;Ar^(2+)在激光偏振平面短轴方向的末态动量谱呈现单峰结构,并且随着椭偏率增大而变宽.轨迹分析显示,椭圆偏振激光脉冲驱动下,非次序双电离仍然是通过再碰撞而发生;随着椭偏率的增大,有效碰撞和单电离之间的时间延迟增加,这是因为椭偏率较大时第一个电子需要经过多次往返才能与母核离子发生有效碰撞.With elliptically polarized laser pulse, the nonsequential double ionization （NSDI） of argon atoms is investigated using fully classical ensemble. The results show that the yield of NSDI decreases with increase of the ellipticity, that the momentum spectrum of the correlated electron from double ionization events in the final state shows a correlated behavior along the long axis of the laser polarization plane and an anticorrelated behavior along the short axis of the laser polarization plane, and that the momentum spectrum distribution of Ar2＋ ion exhibits a single-peak structure at the zero along the short axis of the laser polarization plane, which becomes broader with the increase of the ellipticity. Trajectory back analyses show that the happening of NSDI is still due to recollision, and that the delay time between the collision and the single ionization increases with ellipticity increasing, which is because that the first electron needs more trips shuttling back and forth, so that it can recollide with the parent ion under the more ellipticity.

关 键 词：非次序双电离 椭圆偏振激光脉冲 再碰撞 电子关联 

分 类 号：O562.4[理学—原子与分子物理]