Enhanced Balmer-alpha emission in interpenetrating plasmas

The interpenetration of laser produced plasmas can be detected by the occur rence of charge exchange reactions. Such reactions only occur if highly cha rged ions collide with ions of a significantly lower charge in suitable ene rgy levels. This leads to selective population of a specific level of the h ighly charged ion resulting in an enhancement of particular lines in the re gion of the interaction. In case of interpenetrating carbon plasmas these r eactions lead to enhanced line emission at 18.2 nm (H-alpha line of C VI). We present spatially and temporally resolved investigations of the interact ion region of colliding plasmas;we show results of calculations of the cros s sections for charge exchange obtained with a semi-classical model and com pare measured spectra with calculated ones obtained from a collisional radi ative model.