STUDIES ON VUV LASING WITH NEON-LIKE ALUMINUM IONS

摘要

The collisional-radiative equilibrium model has been developed in order to investigate the population inversion on aluminum plasma. The population inversion has been established between lower 3s (~3P_1~0,~1P_1~0) and upper 3p (~3P_0,~1S_0) levels. The vacuum ultra-violet lasing on neon-like aluminum ions provides wavelengths of 111.9 nm, 143.2 nm, 157.3 nm. The rate of relative density population, between lower 3s ~1P_1~0 and upper 3p ~3P_0 levels, reaches its highest value of 7.16 at the electron density of 10~(19) cm~(-3). The modified expression of optical escape factor, in the case of Doppler profile, was introduced in the calculation of opacity effect on the gain magnitudes. The resonance radiation trapping by 3d configuration alters drastically the gain values. A gain greater than 1 cm~(-1) was found between lasing levels 3s ~3P_1~0 and 3p ~3P_0. The enhancement of gain was due to the pumping of the upper level by dielectronic recombination process from the ground state of fluorine-like and by the inner-shell ionization process from excited levels of sodium-like ions.