Shockhyphen;wave production and plasma motion in CO2hyphen;laserhyphen;irradiated targets

摘要

We use visiblehyphen;light, streaked shadowgraphy to make to first measurements of several transport and expansion phenomena in CO2hyphen;laserhyphen;irradiated foils. Measured velocities of the freehyphen;surface motion, produced by the laserhyphen;driven shock wave, at the foilrsquo;s rear surface yield shock pressures in reasonable agreement with theory. The velocity of plasma expansion from the absorption region is observed to change abruptly after sim;1.5 ns. We speculate that this effect is due to relaxation of the steepened plasma profile. Energy transport from the front to rear surface via the targetrsquo;s edge, which complicated shock studies, is controllable with a simple shield.