Hot electron distribution from short pulse laser plasma

Abstract

Hot electron production and related Bremsstrahlung emission known in long pulse (tens of ps up to ns FWHM) becomes more important in short and ultra short (ps down to tens of fs FWHM) laser plasma interaction because some ten percent of the laser energy are being transferred to hot electrons, as theoretical (Wilks et al 1992, Gibbon 1994) and experimental (Schnürer et al 1995) studies have indicated. Measured hot electron distributions are compared to model predictions in order to gain more knowledge about the laser plasma absorption mechanism. A control of the hot electron production with the driving optical laser parameters is important for the Bremsstrahlung emission, if one wants to optimize short pulse hard X-ray sources. At relativistic driving laser intensities above 1019 W/cm2 hot electron production is the key part in the fast ignitor concept for the inertial confinement fusion (Tabak et al 1994).