K-α emission spectroscopic analysis from a Cu Z-pinch

Abstract Advances in diagnostic techniques at the Sandia Z-facility have facilitated the production of very detailed spectral data. In particular, data from the copper nested wire-array shot Z1975 provides a wealth of information about the implosion dynamics and ionization history of the pinch. Besides the dominant valence K- and L-shell lines in Z1975 spectra, K - α lines from various ionization stages were also observed. K-shell vacancies can be created from inner-shell excitation and ionization by hot electrons and from photo-ionization by high-energy photons; these vacancies are subsequently filled by Auger decay or resonance fluorescence. The latter process produces the K - α emission. For plasmas in collisional equilibrium, K - α emission usually occurs from highly charged ions due to the high electron temperatures required for appreciable excitation of the K - α transitions. Our simulation of Z1975 was carried out with the NRL 1-D DZAPP non-LTE radiation-hydrodynamics model, and the resulting K- and L-shell synthetic spectra are compared with measured radiation data. Our investigation will focus on K - α generation by both impacting electrons and photons. Synthetic K - α spectra will be generated either by self-consistently calculating the K-shell vacancy production in a full Z-pinch simulation, or by post-processing data from a simulation. The analysis of these K - α lines as well as K- and L-shell emission from valence electrons should provide quantitative information about the dynamics of the pinch plasma.