Experimental studies of sodium-like recombination x-ray laser

摘要

Experimental study of a soft x-ray laser for the sodium-like recombination scheme carried out at the LF12 Laser Facility of Shanghai Institute of Optics and Fine Mechanics (SIOM) is reported. Soft x-ray amplification was observed in sodium-like copper ions by line-focused laser irradiation of slab targets. Based on the spatially-resolved measurements, the spatial distribution of the laser gain for the 6g - 4f (72.22 angstroms) transition of sodium-like copper ions was obtained, and the maximum gain coefficients and gain-length products at 550 $mu@m from target surface are 2.0 cm$+$MIN@1$/ and 3.6, respectively. The evolution of spectrally discriminated spatial uniformity of line-shaped plasmas as lasing gain media produced by uniform laser illumination in line-focus is also investigated. It is found that under this experimental condition the line-shaped plasma is very uniform after the optical laser's heating.