The temporal characteristics of Ne-like Ar 46.9nm X ray laser pulse

We calculated the pulse shape of Ne-like Ar 46.9nm X ray laser which population inversion is from the electron impact excitation. We used the Cowan codes to calculate the level energy, radiative transition rate and oscillator strength of the 2s(2)2p(5)3p, 2s(2)2p(5)3s and 2s(2)2p(6) configurations. With the electron impact excitation (deexcitation) rate coefficients, the rate equations are established. Approximating the time dependent curve of electron temperature and density as a square wave, the time dependent curve of populations and 46.9nm laser photon number is calculated. Thus, the pulse shape is obtained. Finally, we analyzed the influence of gain duration, electron temperature and density on the pulse duration.