Feasibility of a laboratory X-ray laser pumped by ultrashort UV laser pulses.

In order to allow widespread application of soft X-ray lasers there is a strong effort worldwide to use as small as possible pump lasers for plasma production. Short pulse lasers (τ ≈ 1 ps), particularly in the UV, have attracted much interest, since extremely high intensities (up to 1018 W/cm2) can be achieved with a relatively high repetition rate. In this article we discuss their merit for soft X-ray laser pumping and possible solutions to the specific problems, for instance pulse front distortion, nonlinear absorption in window materials, plasma formation by short laser pulses and the relatively low total pump energy