X-Ray Laser Driven Gold Planar Targets

A non-equilibrium ionization model is assembled to investigate the subpicosecond ionization dynamics of the hole states, that are created and destroyed when an incident coherent high intensity x-ray laser pulse impinges on planar gold targets. There are two aspects to this modeling. One is the construction of simplified atomic models of gold and of its adjacent ions. Second is the study of the nonlinear optical dynamics and absorption physics of an x-ray pulse interacting with a gold target as a function of the x-ray wavelength, pulsewidth, and intensity. The ionization levels and excited state populations reached during an interaction provide important diagnostics of the x-ray pulse. Of interest are the $\sim $ 4.45 keV x-ray pulse generated in previous KrF experiments\footnote{Borisov \textit{et. al.} J. Phys B \textbf{41} 105602 (2008).} and extensively modeled\footnote{Petrova \textit{et. al.} J. Phys B \textbf{43} 025602 (2010), \textbf{44} 125601 (2011); HEDP \textbf{8} 209 (2012).}$^,$\footnote{Davis\textit{ et. al.} HEDP \textbf{8} 238 (2012).}$^,$\footnote{Whitney\textit{ et. al.}, PRA 003400 (2012).} as well as the x-ray pulses generated at SLAC.