Modeling Double Hole Dynamics in Intense Laser Produced Xenon Cluster Plasmas

When femtosecond laser pulses with intensities greater than $\sim $10$^{19}$W/cm$^{2}$ interact with a cluster of xenon atoms, the atoms are stripped of their N-shell electrons in less than a femtosecond and a Coulomb explosion ensues with ions initially in the ground state of Ni-like xenon. X-ray lasing at $\sim $2.86 {\AA} has been observed in such cluster explosions [1] and gain coefficients were measured. Gains comparable to those measured have been obtained in the single hole states of Co-like xenon in an initial non-equilibrium theoretical analysis of these experiments [2]. Alternatively, x-ray amplification has also been attributed to the generation of population inversions between double and single hole states in the M-shell ions of xenon [3]. In order to investigate the viability of this possibility, we have added double hole states to the Fe-like ionization stage of our detailed ionization dynamic model of Ni-, Co-, and Fe-like xenon [2]. Results from our model calculations will be presented in this talk. \\[0pt] [1] A. B. Borisov, \textit{et. al}., J. Phys. B: At. Mol. Opt. Phys. \textbf{40} (2007) F307. [2] Tz. B. Petrova, \textit{et. al}., J. Phys. B: At. Mol. Opt. Phys. \textbf{43} (2010) 025601. [3] W. Andreas Schroeder, \textit{et. al}., J. Phys. B: At. Mol. Opt. Phys. \textbf{34} (2001) 297.