Analysis of ionization with intense laser radiation

Laser-plasma experiments routinely rely on field ionization for plasma formation. While several analyses of non-relativistic ionization have been carried out [1], they often fail to reproduce experimental observations [2]. Moreover for large laser intensities or for high-Z atoms relativistic effects become important. We have undertaken a numerical study of ionization processes employing three-dimensional, time dependent, deBroglie/Compton wavelength-resolved, parallel algorithms for the Schr\"{o}dinger and Klein-Gordon equations [3]. Along with the numerical analysis we have performed analytic modeling, employing the Schr\"{o}dinger, Klein-Gordon and Dirac equations. Results of the analysis and numerical studies will be presented. In particular we discuss ionization of hydrogen-like Xe, the momentum distribution of ejected electrons and the related Bohmian trajectories. \\[4pt] [1] L.V. Keldysh, Sov. Phys. JETP \textbf{20}, 1307 (1965).\\[0pt] [2] C.I. Moore, \textit{et al}., Phys. Rev. Lett. \textbf{82}, 1688 (1999); A. Ting, et al., Phys. Plasmas 12, 010701 (2005); D. Kaganovich, \textit{et al}., Phys. Rev. Lett. \textbf{100}, 215002 (2008).\\[0pt] [3] D. Gordon {\&} B. Hafizi, J. Comp. Phys. \textbf{231}, 6349 (2012); D. Gordon, B. Hafizi {\&} A. Landsman (to be published).