Theoretical research on characteristics of the gains in nickel-like krypton 32.8 nm laser system

In order to study the plasma state for Ni-like Kr 32.8 nm laser, the atomic parameters of the Ni-like Kr 32.8 nm laser system are calculated with Cowan physical code. Based on the level parameters, the rate equations of energy level are established and solved under the quasi-steady-state approximation. The relative population density and the relative gain coefficient between the upper and lower levels of the laser are calculated with different electron temperatures and electron densities. The influence of the sub-levels of 3d⁹4p, 3d⁹4d and 3d⁹4f configurations on laser generation is analyzed as well. The optimum plasma state for Ni-like Kr 32.8 nm laser generation is obtained through theoretical calculation. The best electron temperature is about 75 eV and the optimum electron density is about 10¹⁸ cm^-3. These calculation results provide theoretical foundation for the experiment of Ni-like Kr 32.8 nm laser pumped by capillary discharge in the future.