XFEL and HHG interaction with matter:Effects of ultrashort pulses and random spikes  

作　　者：F.B.Rosmej V.A.Astapenko E.S.Khramov 

机构地区：[1]Sorbonne University,Faculty of Science and Engineering,UMR 7605,Case 128,4 Place Jussieu,F-75252 Paris Cedex 05,France [2]LULI,Ecole Polytechnique,CEA,CNRS,Laboratoire pour l’Utilisation des Lasers Intenses,Physique Atomique dans les Plasmas Denses,F-91128 Palaiseau,France [3]Moscow Institute of Physics and Technology-MIPT,Institutskii per.9,Dolgoprudnyi 141700,Russia [4]National Research Nuclear University MEPhI(Moscow Engineering Physics Institute),Kashirskoe sh.31,Moscow 115409,Russia

出　　处：《Matter and Radiation at Extremes》2021年第3期1-7,共7页极端条件下的物质与辐射（英文）

基　　金：funded by RFBR Grant No.19-32-90016,Ecole Polytechnique,the Cooperation Agreement between the Sorbonne University and MIPT,and the MIPT 5-top-100 program;supported by the Competitiveness Program of NRNU MEPhI in the framework of the Russian Academic Excellence Project.

摘　　要：The theory of photoionization describing the interaction of x-ray free-electron laser(XFEL)pulses and high-harmonic-generated(HHG)radiation is generalized to ultrashort laser pulses,where the concept of the standard ionization probability per unit time in Fermi’s golden rule and in Einstein’s theory breaks down.Numerical calculations carried out in terms of a generalized photoionization probability for the total duration of pulses in the near-threshold regime demonstrate essentially nonlinear behavior,while absolute values may change by orders of magnitude for typical XFEL and HHG pulses.XFEL self-amplified spontaneous emission pulses are analyzed to reveal general features of photoionization for random and regular spikes:the dependences of the nonlinear photoionization probability on carrier frequency and spike duration are very similar,allowing an analytical expectation value approach that is valid even when there is only limited knowledge of random and regular parameters.Numerical simulations carried out for typical parameters demonstrate excellent agreement.

关 键 词：RANDOM INTERACTION nonlinear 

分 类 号：O17[理学—数学]