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

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

作者机构：Sorbonne UniversityFaculty of Science and EngineeringUMR 7605Case 1284 Place JussieuF-75252 Paris Cedex 05France LULIEcole PolytechniqueCEACNRSLaboratoire pour l’Utilisation des Lasers IntensesPhysique Atomique dans les Plasmas DensesF-91128 PalaiseauFrance Moscow Institute of Physics and Technology-MIPTInstitutskii per.9Dolgoprudnyi 141700Russia National Research Nuclear University MEPhI(Moscow Engineering Physics Institute)Kashirskoe sh.31Moscow 115409Russia 

出 版 物：《Matter and Radiation at Extremes》 (极端条件下的物质与辐射（英文）)

年 卷 期：2021年第6卷第3期

页      面：1-7页

核心收录：

学科分类：0808[工学-电气工程] 07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 0807[工学-动力工程及工程热物理] 0827[工学-核科学与技术] 0703[理学-化学] 0701[理学-数学] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

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. 

主　　题：random interaction nonlinear 

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.