Demonstration of large GL x-ray laser in Ne-like germanium

Summary form only given, as follows. X-ray laser research at China Academy of Engineering Physics has focused on pursuing large gain-length products for Ne-like germanium 3p-3s transitions. Two beams of Nd-glass laser were used with 700J/1ns at 1.06μm wavelength. In order to overcome refraction losses of x-ray laser transmission in a long plasma medium, a scheme of four targets in series was proposed. The GL values obtained for 23.2nm and 23.6nm spectrums reach 16.5 and 15.7 respectively. It approach saturation. Furthermore, these soft x-ray emissions have narrow divergence. The divergence angle is (3-4)mrad.