Soft X-ray amplification for Li-like and Be-like Si ions by irradiation of pulse-train laser

摘要

Amplified spontaneous emissions (ASE) of Si XII and XI lines were observed in a recombining Si plasma produced by a low-power Nd-glass laser. The gain length products are 1.7 and 0.9 for the lines of 3d-5f (88.84 A) and 3d-4f (130.02 A) transitions in Si XII and 0.9 and 0.6 for the 3d-5f (102.3 A) and 3d-4f (147.6 A) in Si XI, respectively. The laser has an envelop of 5 ns-FWHM and contain several short pulses of 100 ps-FWHM with the intervals of 350 ps between pulses. This pulse-train laser can effectively produce the high temperature plasma.