Spatial and spectral parameters of superthermal particle extension in laser plasma experiments with a picosecond laser pulse

摘要

Abstract: On the PROGRESS laser facility the spectral and spatial characteristics of suprathermal particles extension in experiments with flat targets and picosecond duration of heating laser pulse are investigated. The opportunity to use multiframe pulse interferometry for visualization of spatial and power parameters of suprathermal particle extension alongside with traditional means of charged particle diagnostics with an irradiation of flat targets in an atmosphere of residual gas are considered. The basic part of laser radiation with energy up to 20 J and pulse duration 200 ps is directed to target chamber. A few parts of a heated laser pulse amplified and compressed with Raman backscattering compressor up to 10-20 ps with energy 20-30 mJ and wavelength 622 nm was used as optical diagnostic beam in multiframe interferometer. Series of experiments both with p and with the s-polarized radiation were carried out. On the basis of received interferograms the measurements of spectral parameters of fast particles by traditional methods with time-of-flight technique are carried out. This data are compared with spatial distribution of fast ions at picosecond laser-plasma experiments and laser intensity up to 10$+19$/ W/cm$+2$/ on the PROGRESS-P laser. !3