飞秒光场中锂原子三重电离的光电子关联动量与能量谱研究(特邀)  

Electron Correlation Momentum and Energy Spectrum in Triple Ionization of Lithium by the Femtosecond Laser Field(Invited)

作　　者：刘士炜 叶地发[2] 刘杰 LIU Shiwei;YE Difa;LIU Jie(Beijing Computational Science Research Center,Beijing 100193,China;Institute of Applied Physics and Computational Mathematics,Beijing 100088,China;Graduate School,China Academy of Engineering Physics,Beijing 100193,China)

机构地区：[1]北京计算科学研究中心,北京100193 [2]北京应用物理与计算数学研究所,北京100088 [3]中国工程物理研究院研究生院,北京100193

出　　处：《光子学报》2022年第8期329-336,共8页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.12174034,12047510);国家自然科学基金联合基金(Nos.U1930402,U1930403)。

摘　　要：理论研究了飞秒光场中锂原子的三重电离问题。改进经典轨道蒙特卡罗方法获得了锂原子基态的稳定构型并数值计算了激光强度范围为10^(13)W/cm^(2)至1017W/cm^(2)锂的电离率。分析电离后Li^(3+)的动量谱,揭示了包括非序列三重电离与序列三重电离的电离机制。根据Dalitz图中绘制的电子能量分布的关联谱,发现在非序列三重电离过程中存在明确的(e,3e)电子关联效应,即率先电离的电子与母离子发生再散射,使得内壳层的两个电子同时电离。此外,模拟表明即使在强度高达10^(17)W/cm^(2)的序列三重电离区域也存在电子再散射过程。The interaction between atoms and intense laser fields plays an important role in the field of ultrafast physics,which has become a powerful experimental technique to explore the structure and dynamics of matter.One of the critical issues is to explore the mechanism of laser-driven electron re-scattering process in,e.g.,above-threshold ionization,high-order harmonic generation,and NonSequential Double/Multiple Ionization(NSDI/NSMI).Among them,the NSDI/NSMI is particularly interesting since it is a prototypical example for studying the electron-electron(e-e)correlation.During the past years,the general picture of NSDI has been established.In comparison,the NSMI is less wellunderstood although a series of experimental data have been collected,for example,extremely highly charged ions up to Ar^(16+),Kr^(19+),and Xe^(26+)have been produced in super-strong laser fields.Here,the involvement of the multi-shell multi-electron,as well as highly nonlinear relativistic and non-dipole effects,makes the electron dynamics much more complicated.As a result,the theoretical explanation is hindered and lagged far behind partially due to the fact that solving the full-dimensional Time-Dependent Schr?dinger Equation(TDSE)is currently limited to two-electron systems,leaving the dynamics of NSMI highly unexplored.On the other aspect,the Classical Trajectory Monte Carlo(CTMC)approach has been widely applied to atomic and molecular collisions and ionization of atoms by strong laser fields,which can be readily implemented in many-body systems and provide intuitive pictures to the dynamical processes of interest.It should be noted that,however,a classical multi-electron atom with Coulomb interactions is typically unstable and might suffer nonphysical auto-ionization,which needs feasible′quantum′modifications.this article investigates the laser-driven lithium triple ionization by the classical trajectory Monte Carlo with the Heisenberg potential(CTMC-H)model.The model introduces the Heisenberg potential to mimic the Heisenberg uncertai

关 键 词：强场激光物理 超快过程 碱金属原子 多重电离 电子关联 

分 类 号：O436[机械工程—光学工程]