Soft x-ray lasing and its spatial characteristics in a lithium-like silicon plasma

Abstract
Experimental study of soft x-ray laser carried out on the LF12 Laser Facility of SIOM (Shanghai Institute of Optics and Fine Mechanics) is reported. Soft x-ray amplifications were observed in lithium-like silicon ions by line-focused laser irradiation of slab targets. Based on the time-integrated measurements, the gain coefficients are 1.5 and 1.4 cm−1 for the 5f–3d (88.9 Å) and the 5d–3p (87.3 Å) transitions of lithium-like silicon ions, respectively. In addition, the spatial characteristics of the laser lines are also presented.