Scale-length optimizing of short pulse CuKα laser-plasma sources

Abstract

The authors present experimental results showing how the use of a high contrast femtosecond laser system allows better optimization of Kα emission from a Cu target. The shorter scale-length preformed plasma is better optimized for resonance absorption of the laser light when the laser is moved away from best focus. The experimental data show a central peak of Kα emission at tight focus with strong secondary peaks at large offset. The use of these secondary peaks results in a much reduced hard x-ray background and should lead to shorter Kα pulses than at tight focus.