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

Summary form only given. Previous experiments on the 1-MA “Zebra” generator at UNR studied precursor plasmas with Ni-60 alloy (96% Cu) wire arrays. Those precursor plasmas were shown to consistently have electron temperatures >; 400 eV ¹. New recent experiments performed on Zebra using cylindrical wire arrays (CWA) continue to emphasize stronger radiating precursor plasma but from other mid-atomic number wire arrays. Time-integrated spatially-resolved (TISR) and time-gated spatially-integrated (TGSI) x-ray spectral data, time-integrated and time-gated pinhole x-ray images, shadowgraphy, as well as optical streak camera images were obtained during the recent mid-atomic number (Cu, brass, and alumel) CWA experiments. Preliminary results on these CWA are consistent with previous Ni-60 results. Non-LTE kinetic models of Cu, Zn, and Ni have been applied to account for the L-shell radiation from precursor and main x-ray burst plasmas. 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.