High gain x-ray lasers pumped by transient collisional excitation

Abstract

Abstract. We present recent results of x-ray laser amplification of spontaneous emission in Ne-like and Ni-like transient collisional excitation schemes. The plasma formation, ionization and collisional excitation can be optimized using two laser pulses of 1 ns and 1 ps duration at table-top energies of 5 J in each beam. High gain of 35 cm -1 has been measured on the 147 Å 4d→4p J=0→1 transition of Ni-like Pd and is a direct consequence of the nonstationary population inversion produced by the high intensity picosecond pulse. We report the dependence of the x-ray laser line intensity on the laser plasma conditions and compare the experimental measurements with hydrodynamic and atomic kinetics simulations for Ne-like and Ni-like lasing.

Determination of transient gain lifetime for a 1-ps driven nickel like palladium 14.7 nm x-ray laser

“…5 The demonstration of high gain, in excess of 35 cm -1 , on the Ni-like analog of the transient scheme for the Pd 4d→4p J=0→1 line at 14.7 nm has been a further step towards attaining a shorter wavelength x-ray laser pumped by table-top scale lasers. 5,6 As a result of the fast picosecond driving pulse used to generate the population inversion, it is calculated from numerical simulations that transient collisional excitation can produce very high gains above 100…”