Bremsstrahlung soft X-ray emission from clusters heated by a Gaussian laser beam

Abstract

AbstractA theoretical model of soft X-ray emission from laser irradiated clusters is developed. An intense short pulse laser of Gaussian radial and temporal profiles impinged on a clustered gas jet, heats the cluster electrons, leading to Bremsstrahlung emission of X-rays. As the clusters expand under hydrodynamic pressure, plasma frequency of the cluster electrons ωpedecreases. When plasma frequency of a cluster approaches plasma resonance${\rm \omega}_{\,pe} = \sqrt{3} {\rm \omega}$(where ω is the laser frequency), the electrons are resonantly heated by the laser and a rapid rise in X-ray emission occurs. After a while, when cluster expansion detunes the plasma resonance, X-ray emission falls off.