Katsoulis G P, Emmanouilidou A
Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
Sci Rep. 2019 Dec 11;9(1):18855. doi: 10.1038/s41598-019-55066-1.
We study double ionization of He driven by near-single-cycle laser pulses at low intensities at 400 nm. Using a three-dimensional semiclassical model, we identify the pathways that prevail non-sequential double ionization (NSDI). We focus mostly on the delayed pathway, where one electron ionizes with a time-delay after recollision. We have recently shown that the mechanism that prevails the delayed pathway depends on intensity. For low intensities slingshot-NSDI is the dominant mechanism. Here, we identify the differences in two-electron probability distributions of the prevailing NSDI pathways. This allows us to identify properties of the two-electron escape and thus gain significant insight into slingshot-NSDI. Interestingly, we find that an observable fingerpint of slingshot-NSDI is the two electrons escaping with large and roughly equal energies.
我们研究了在400纳米低强度下由近单周期激光脉冲驱动的氦原子双电离。使用三维半经典模型，我们确定了主导非顺序双电离（NSDI）的路径。我们主要关注延迟路径，即一个电子在再碰撞后有时间延迟地电离。我们最近表明，主导延迟路径的机制取决于强度。对于低强度，弹弓式NSDI是主导机制。在这里，我们确定了主导NSDI路径的双电子概率分布的差异。这使我们能够识别双电子逃逸的特性，从而深入了解弹弓式NSDI。有趣的是，我们发现弹弓式NSDI的一个可观测特征是两个电子以大致相等的较大能量逃逸。
