Time-resolved XUV radiation diagnostics from nitrogen discharge Z-pinch plasma

XUV radiation from nitrogen filled capillary discharge plasma was diagnosed using a 10 4 grooves/mm SiNx free-standing transmission grating. The resolution bandwidth of 0.3 nm was achieved. Time dependence of 13.4 nm line emitted power was recorded by photomultiplier in order to verify inherence of resonant radiation emission corresponding to NVII 2-3 laser transition. An increase of emitted power is expected during the pinch decay caused by recombination processes. We report here results obtained with 90 mm long capillary discharge supplied by a current pulse with maximum amplitude of 50kA and quarter-period of 80 ns. This high-current pulse was generated by a 1.5 ohm water line high-voltage generator which is used for underwater wire explosion experiments and which was adjusted for capillary discharge design using results of PSPICE simulations. Initial nitrogen pressures were varied in the range of 20 ÷ 500 Pa. MHD and kinetic simulations of the discharge plasma were performed and compared with experimental data. Simulations were performed with presumption of wall ablation. The capillary wall and electrodes material emission lines were also identified in measured spectra.