Analysis of K-shell HED Plasmas in X-Pinch and Laser Experiments at UNR
Résumé
Summary form only given. High Energy Density (HED) plasmas were produced in two sets of experiments: using a Z-pinch generator and a high power laser at the Nevada Terawatt Facility (NTF) of the University of Nevada, Reno (UNR). Each experiment has its unique characteristics and can be used to gain better understanding of HED plasmas. X-pinch experiments were performed at enhanced current on the Zebra generator using the Load Current Multiplier (LCM) and generated radiation yield up to 19 kJ/cm. These experiments used Ti alloy wires (6% Al, 4% V) for a first look at X-pinches at 1.5-1.7 MA at UNR. A full set of diagnostics was fielded including time-integrated spatially-resolved (TISR) and time-gated spatially-integrated (TGSI) x-ray spectrometers, time-integrated and time-gated pinhole x-ray cameras, and shadowgraphy. Many interesting results were found such as: i) the appearance of characteristic emission of Ti (wire material) and Fe (anode) in different orders of reflection at 30 ns prior to the first x-ray burst that was recorded for the next 15 ns, ii) prominent K-shell Al radiation despite the low percentage of Al in the alloy in both TGSI and TISR spectra, iii) K-shell Al radiation that corresponds to 400-550 eV plasmas starting near the first x-ray burst. Additionally experiments using the Leopard laser were performed on flat Al targets using a 0.8 ns pulse duration and two different target thicknesses (10 and 50 μm) that produced K-shell Al spectra of higher electron density. K-shell Al spectra of X-pinches, both TGSI and TISR, were modeled and compared with the laser-produced plasma results. The advantage of using alloyed Ti wires to study K-shell HED plasmas is highlighted. Future work is discussed.