Time-resolved spatial distribution of an ablative capillary discharge obtained with a pinhole camera

Time- and space-resolved measurements of an ablative polyethylene capillary discharge using a pinhole camera are presented in this paper. Measurements with and without a 0.1 mu m thick polyimide filter allowed us to identify the soft x-ray production zones. The images show that the plasma, mainly co mposed of highly ionized carbon, was not detached from the capillary wall d uring the heating phase. This plasma behaviour does not favour the developm ent of a recombination-pumped x-ray laser. For two capillary lengths, the p lasma dynamics were observed at constant power density in a first run and a t identical current waveform in a second run. In both cases, they were diff erent and could induce errors on gain measurement when varying capillary le ngths. To our knowledge, this is the first report of time-resolved pinhole images of ablative carbon capillary discharges used as soft x-ray sources.