Optimization of pump laser conditions for production of maximum gain of Ne-like Ge soft x-ray laser

Laser produced plasma can be used as the sources of soft X-ray laser. The ability to control the laser quality and its gain coefficient by controlling laser and plasma’s parameters is one of the advantages of this method. In this study, a pump pulse assistant along with a pre-pulse is irradiated on a geranium target as the plasma active medium, thenthe gain of soft X-ray laser at wavelength 19.6 nm is calculated. In order to analyze the effect of laser parameters such as intensity, pulse length, and time delay between two pulses, MED103 hydrodynamic code has been used. The simulation results show that there is optimal pulse duration for the pre-pulse as well as the main pump pulse to achieve the maximum gain of soft X-ray laser. In addition, according to the results, by increasing the pre-pulse intensity the amount of soft X-ray laser gain initially increases and then decreases, while by enhancing the main pulse intensity, it keeps increasing. Also, the optimal spatiotemporal regions of the soft X-ray laser gain for different time delays of two pulses are given.