Highly efficient tabletop x-ray laser atλ=41.8 nm in Pd-like xenon pumped by optical-field ionization in a cluster jet

Abstract

The atomic-kinetic calculations of gain at 41.8 nm in Pd-like xenon are performed. The interpretation of known experiments has proved that x-ray laser in Pd-like xenon is feasible in the extremely wide range of atomic densities: 10${}^{17}$ \ensuremath{\leqslant} [Xe${}^{8+}$] \ensuremath{\leqslant} 3 \ifmmode\times\else\texttimes\fi{} 10${}^{19}$ cm${}^{\ensuremath{-}3}$. This result is due to the large cross sections (and rates) of level excitations in Pd-like xenon by electron impact. We propose a highly efficient tabletop x-ray laser pumped by optical-field ionization in a xenon cluster jet. The efficiency of \ensuremath{\sim}0.5% is possible with a pump laser pulse energy of \ensuremath{\geqslant}0.001 J and an intensity of \ensuremath{\sim}10${}^{16}$ W/cm${}^{2}$.