Modeling of L-Shell Zinc and Copper Radiation from Brass Planar Wire Array Implosions on the 1 MA Zebra at UNR

Summary form only given. The study of radiative properties of L-shell radiators from the new mid-Z wire materials is important for the development of diagnostics on the future SNL ZR. In the present work we extend our previous study of L-shell radiators of copper and stainless steel wire arrays to brass arrays. Modeling of X-ray spectra from the implosion of brass wire array loads is challenging because of the overlapping contributions of L-shell spectra from the Zn and Cu ions. L-and K-shell X-ray spectra have been accumulated from brass planar wire array experiments on the 1MA Zebra generator. They have been analyzed in detail and compared with the similar spectra from implosions of copper planar and cylindrical wire arrays. In particular, L-shell spectra recorded bv a KAP crystal cover the spectral range from 8 to 17 Aring for axially-resolved time integrated spectra and the narrower spectral interval from 6 to 11 Aring for time-gated spatially integrated spectra. Non-LTE Cu and Zn kinetic models have been applied to account for the K-and L-shell radiation from these ions. The Cu model was successfully applied before to study radiation from X-pinches and wire arrays from Zebra and the Zn model is a new model developed in this work. In general, modeling of x-ray spectra from mid-Z wire materials indicates a moderate Te of 200-400 eV for L-shell plasmas and much higher Te of 1.5-2.5 keV for K-shell plasmas. Though both L-and K-shell spectra from brass arrays were modeled the emphasis of this work was on L-shell modeling. Modeling of high quality time-gated spectra collected in these experiments provided valuable information on temporal plasma evolution during the stagnation phase. Modeling of the EUV spectra from these shots will also be presented and compared with similar spectra from copper shots.