X-ray yields of plasmas heated by 8-nsec neodymium laser pulses

36 elemental targets, beryllium through uranium, were irradiated with 8-nsec FWHM Nd : glass laser pulses focused to ∼4×1013 W/cm2. X-ray spectra were recorded with a convex-crystal spectrograph and with a 22-channel PIN-diode spectrometer. Line and continuum spectra indicated temperatures of 36589 eV. Total x-ray irradiances in the energy range 0.7–20 keV showed strong peaking as a function of atomic number with a maximum conversion efficiency of 9.6% relative to the incident laser energy. An indication of enhanced N-shell x-ray emission near U is reported here for the first time.