Spectrum of continuous x-ray emission from a laser plasma and deviations of the electron distribution function from Maxwellian form

The absorber method was used in an experimental study of the bremsstrahlung and recombination radiation emitted by (CD₂)_n and Fe plasmas irradiated with laser fluxes of ~10¹⁴ W/cm² density. It was established that in the case of the Fe plasma the x-ray emission in the 1–10 keV range corresponded to a Maxwellian distribution with an electron temperature of ~0.8 keV. In the case of the (CD₂)_n plasma there were deviations of the distribution function from the Maxwellian form indicating an increase in the number of high-energy electrons (the electron temperature varied from 0.45 to 6 keV). Hard radiation with photon energies in excess of 100 keV was emitted from various targets. The intensity of this radiation and the deviation of the electron distribution function from the Maxwellian form increased with the density of the laser flux and decreased with the atomic number of the target material.