On the gain of electronic collision excitation X-ray lasers in neon-like germanium ion

The inversion and gain of the electron-collisional excitation pumping X-ray laser depend on four parameters (electron density Ne, Electron temperature Te, width of gain region ΔR and velocity gradient of lasing medium dv/dz) describing the internal state of plasmas. As an example, the dependence of the inversion and gain of laser lines at 19.6 nm, 23.2 nm and 23.6 nm in neon-like germanium ion on Ne and Te is studied. In the gain region with a typical spatial width (ΔR 100 μm) and velocity gradient of lasing medium (dv/dz = 1.3 x 109s-1), the effect of resonance lines-trapping on the gain is discussed and the objective regions of gain are given for these laser lines. In addition, the effect of dielectronic recombination process on charge-state distribution is discussed