Gain Measurement on a 18.2-nm Carbon Recombination Laser Produced by an Intense CO2 Laser

Abstract

We propose a cylinder-type target as a carbon recombination laser medium made of 30-μm thick parylene (C8H8) whose diameter and length are 3mm and 3mm-12mm, respectively. The high power CO2 laser (500J in 50ns) irradiates a 2500-Å thick parylene foil attached to the end of the cylinder. Then the plasma from the thin foil and the cylinder wall produced by the scattered light expands and is confined in the cylinder, producing an almost uniform plasma without magnetic field. The plasma length of more than 1 cm was observed with x-ray pinhole camera. We measured the gain of CVI 3d-2p line (18.2 nm) using the axial and the transverse spectrometers. The maximum gain length product of 2.4 at cylinder length of 12 mm was obtained.