Thin foil electron beam impulse experiments

Measurements were made of the impulse produced by thin, metallic foils that had been rapidly and uniformly heated in depth, to melt or vaporization by an electron beam. Blowoff predictions were done using two hydrocodes: PUFF, with the GRAY three phase equation of state, and CHART, with its three phase equation of state. An acceptable correlation variable, folding in electron beam and material characteristics, was derived and used successfully to plot and analyze predicted and measured data trends. We conclude that PUFF and CHART, with their present equations of state, predict impulse correctly within tolerances of +-30 percent. Unfortunately, the lack of repeatability of the electron beam machine precludes its use for doing more accurate equation of state measurements. (9 figs, 5 tables, 10 refs.) (auth)