Simulation and optimization of the picosecond-laser-driven Ne-like Ge x-ray laser

Abstract

We report numerical simulation of a collisionally pumped transient gain x-ray laser in Ne-like Ge ions. The laser system is calculated with a simplified atomic physics model and a self-similar expansion model. The validity of the solution is verified by a comparison of the calculated results for the Ne-like Ge J=0–1 x-ray lasers with the published results attained with sophisticated models. The effects of the opacity of the Ne-like ion 2–3 resonant lines and the pump laser’s pulse width on the dynamics of the transient gain are investigated through numerical calculations. It is found that the opacity affects the delay of the peak gain with respect to the peak of the pump pulse, the gain duration, and the peak gain coefficient as well. The driving laser conditions (laser wavelength, intensity, and pulse width) for the Ne-like Ge J=0–1 lasers are optimized. The results show that a moderate laser wavelength is good for a possible compromise between a high peak gain and a long gain duration.