Resolving the enhanced nonlinear double excitation of helium in intense ultra-short extreme-ultraviolet pulses

28th International Conference on Photonic, Electronic and Atomic Collisions

Liu, Chien-Nan^1 ; Hishikawa, Akiyoshi^2 ; Morishita, Toru^3

Department of Physics, Fu-Jen Catholic University, Taipei

24205, Taiwan^1

Department of Chemistry, Graduate School of Science, Nagoya University, Aichi

464-8602, Japan^2

Department of Engineering Sciences, University of Electro-Communications, Tokyo

182-8585, Japan^3

关键词: Double excitations;    Extreme ultraviolet pulse;    Extreme ultraviolets;    Multiphotons;    Photon energy;    Theoretical study;    Three photon absorption;    Transition energy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/488/3/032047/pdf
DOI  :  10.1088/1742-6596/488/3/032047

来源: IOP

【 摘 要 】

We present a theoretical study for multiphoton double excitation of He atoms exposed to an intense ul-trashort extreme-ultraviolet (EUV) pulse, where the photon energy coincides with the transition energy from the ground state to a Rydberg state. We identify the mechanism of the enhanced three-photon absorption probability as observed in the experiment.