K-shell radiation yields on a 60 MA Z-pinch generator

Summary form only given. Z-pinch driven plasmas produce the highest yield among K-shell line emission sources. Recently measured yields on the refurbished Z generator (~20 MA) include: 270 kJ for Al (E>;1 keV); 75 kJ for stainless steel (SS, E>;5 keV); and 25 kJ for Cu (E>;5 KeV). Gas puff experiments are planned for the summer of 2012 and predictions for the Ar (E>;3.1 keV) K-shell yield are >; 300 kJ. Clearly for a given generator the K-shell yields decrease as the atomic number of the load material increases. Of interest for future pulsed power generators of higher current is the enhancement in K-shell yields for the above materials, and the potential for significant yields above 10 keV from loads of higher atomic number. In this work we consider a 60 MA generator and examine the K-shell yields for Ar and SS, as well as for Kr (E>;13 keV), Mo(E>;18 keV), and Ag(E>;22 keV). The simulations for the non-LTE radiation magneto-hydrodynamics are performed with 1D radial (DZAPP) and 2D r-z (MACH2-TCRE) codes. These simulations employ an equivalent circuit for the generator including current losses, use detailed configuration accounting including fine structure for the atomic physics with collisional-radiative equilibrium kinetics, and treat the line transport with the probability-of-escape formalism. The 60 MA driver is predicted to couple ~8 MJ into the load and produce over 2 MJ of Ar, ~1 MJ of SS, and ~200 kJ of Kr K-shell. For Mo the conversion efficiency to K-shell remains as high as ~1%, giving ~80 kJ. The effects of a larger current loss in the MITL and time dependent ionization kinetics will discussed.