Saturated X-Ray Lasers

Saturated operation of an X-ray laser is desirable as a high output irradiance is obtained with reduced shot-to-shot variation. The potential of saturated X-ray laser output in probing plasma samples is first investigated. The laser pumping requirements to scale Ni-like saturated X-ray laser output to shorter wavelengths is then analysed using published atomic physics data and a simple 4-level laser model for gain. A model of amplified spontaneous emission (ASE) has been modified to accurately predict experimentally observed saturation behaviour obtained in different experiments at the Rutherford Appleton Laboratory. In particular, the effects of travelling wave pumping with short duration (similar to 1ps) laser pulses are investigated. Simulations of Ne-like Ge resonance line emission are compared to experimentally measured spectra.