Auger effect in the presence of strong x-ray pulses

Abstract

We study the role of propagation of strong x-ray free-electron laser pulses on the Auger effect. When the system is exposed to a strong x-ray pulse the stimulated emission starts to compete with the Auger decay. As an illustration we present numerical results for Ar gas with the frequency of the incident x-ray pulse tuned in the $2{p}_{3/2}--4s$ resonance. It is shown that the pulse propagation is accompanied by two channels of amplified spontaneous emission, $4s--2{p}_{3/2}$ and $3s--2{p}_{3/2}$, which reshape the pulse when the system is inverted. The population inversion is quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The results of simulations show that the propagation of the strong x-ray pulses affect intensively the Auger branching ratio.