Analysis of new Cu precursor wire array experiments on the 1-MA pulsed power generator at UNR

The experiments studied the variation in the precursor with different numbers of wires and wire array diameters. Preliminary results show a single X-ray pulse that resembles the shape, duration, and timing of the precursor observed on earlier shots. Therefore not only time-gated spatially-integrated (TGSI) but also time-integrated spatially resolved (TISR) X-ray spectra were generated by the precursor plasmas in shots when the main X-ray burst was negligible. Non-LTE kinetic models of Cu and Ni have been applied to account for the L-shell radiation from the Cu and Ni ions. The advantage of using Cu alloys with a small percentage of Ni for diagnostics of Cu wire arrays are illustrated. The resulting plasma parameters from modeling of TGSI and TISR spectra together with analysis of corresponding images allow for the study of precursor plasma formation in time and in space, respectively.