X-ray flux from a burnthrough Au foil

The experiments reported in this paper were undertaken to measure the rear x-ray flux of foils having different thicknesses. The targets were burnthrough foils, planar free-standing Au foils and CH supported Au foils, that were nearly entirely ablated during the laser pulse. The x-ray flux from the non-irradiated rear side is of sufficient intensity that it can serve as an x-ray heating source, backlight, or photon pump. The foils were irradiated with one smoothed beam of Nova which provided approx. 3300 J of 2 omega(sub 0) light in a 1 nsec square pulse. The primary diagnostics measured absolute flux and transmitted laser light. The time-dependent absolute flux measurements, the total-integrated energy of the x-ray spectrum, and the temporal evolution will be discussed.