Radiation emission from ultra-relativistic plasma electrons in short-intense laser light interactions

9th International Conference on Inertial Fusion Sciences and Applications

Ondarza-Rovira, R.^1 ; Boyd, Tjm^2

Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, México, Distrito Federal

11801, Mexico^1

Centre for Theoretical Physics, University of Essex, Wivenhoe Park, Colchester

CO4 3SQ, United Kingdom^2

关键词: Harmonic orders;    Harmonic spectrum;    High order harmonics;    Particle-in-cell simulations;    Power law decay;    Radiation emissions;    Relativistic plasmas;    Single particle;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/717/1/012110/pdf
DOI  :  10.1088/1742-6596/717/1/012110

来源: IOP

【 摘 要 】

Intense femtosecond laser light incident on overcritical density plasmas has shown to emit a prolific number of high-order harmonics of the driver frequency, with spectra characterised by power-law decays. When the laser pulse is p-polarised, plasma effects do modify the harmonic spectrum, weakening the so-called universal decay index p = 8/3 to 5/3. In this work appeal is made to a single particle radiation model in support of the predictions from particle-in-cell (PIC) simulations. Using these, we further show that the emission radiated by electrons -those that are relativistically accelerated inside the plasma, after being expelled into vacuum, the so-called Brunel electrons- is characterised not only by the plasma line but also by ultraviolet harmonic orders characterised by the 5/3 decay index.