Fast-electron production in laser-heated plasmas

The continuum X-ray emission from laser-heated targets gives a measure of the energy deposited in superthermal electrons and an estimate of the spectrum and the average electron energy. The validity of the analysis is, however, limited by possible non-collisional energy-loss processes in the pellet corona. If this effect is ignored, fits to experimental X-ray spectra from glass microspheres at 1.06-µm laser wavelength can be readily obtained showing 15%–48% of the absorbed energy in fast electrons.