Plasma clouds collisions and ion trappingat laser–irradiated double–foil targets

摘要

Colliding plasma clouds produced at single–side laser–irradiated double–foil Al/Mg targetsrnrepresent a well–defined model environment for studying the plasma wall interactions. The frontrnAl foil burns through before the laser pulse maximum, thus the forward–accelerated Al ions arernnot trapped by the cold Mg foil but collide with the Mg plasma. The complex satellite–richrnstructure observed in emission spectra of the Al Ly α group is interpreted using the collisional–rnradiative code MARIA and discussed in terms of interaction of counter–propagating plasmas, inrnparticular trapping, deceleration and thermalization of the Al ions close to the Mg foil. Thernqualitative analysis of the observed spectra is supported by the 2D hydrodynamic modeling of thernexpanding plasma. Prospective use of the J–satellite line shifts in diagnosis of colliding plasmas isrndiscussed.