Scaling of collisionally pumped 3s-3p lasers in the neon isoelectronic sequence

Abstract

Population inversions between the 3p and 3s levels of neonlike ions with atomic numbers Z=14, 18, 22, 26, 32, and 36 have been calculated. The population inversions result from the preferential population of the 3p level by electron collisional excitation from the ground configuration of the ion and occur over a wide range of electron temperature and electron density (from 1017 cm−3 for Si V to 1022 cm−3 for Kr XXVII). For all ions that are studied, the maximum value of the population inversion (N3p/g3p−N3s/g3s) for the transition 3p 1S0−3s uP1 (where u represents the upper of the singlet and triplet levels) is found to be approximately equal to 4×10−3 NI, where NI is the total density of neonlike ions. With the exception of Si V, laser gains greater than 1 cm−1 are possible for all the ions that are considered, and the gain increases with atomic number Z. For Si V and lower-Z ions, electron collisional mixing of the upper and lower laser levels restricts the electron density at which the population inversion occurs and limits the laser gain to values less than 1 cm−1. The scaling of the laser gain and the plasma parameters with atomic number Z is presented. For an electron density of 1021 cm−3, the optimum atomic number Z that results in the highest gain on the 3p 1S0−3s uP1 transition is Z=26 (Fe XVII), and the gain is equal to 30 cm−1.

Gain Coefficient Calculation for Short Wave Laser Emission from Sodium like Co

“…levels will be negligible compared to collisional depopulations and all level population become independent of electron density and approximately equal (see Figures 1 and 2). The population inversion is largest where electron collisional de-excitation rate for the upper level is comparable to radiative decay for this level [21]. Form our study, it was found that the gain coefficient was very low at (1/4 ionization potential) for all elements, so the results of gain coefficient and reduced population have not been mentioned.…”

Studies on Vuv Lasing with Neon-Like Aluminum Ions

“…The population inversion was predicted in optically thin Ne-like system [1,4] with only 27 levels of n = 3 and without including the ionization and dielectronic recombination atomic processes. The elaborated inodels which have been recently developed for Ne-like system [2,5,7,8] take into account more excited levels of lasing ions and include some levels of both F-like and Na-like ions.…”

“…However, only 27 levels belonging to the configurations 1s 2 2s2 2p6 , 1s2 2s2 2ρ5 3s, 1s2 2s2 2p5 3p, and 1s2 252 2p5 3d of these ions have been taken into account. The ionization and dielectronic recombination processes, neglected in this simulation [1,4], have shown a significant effect on the gain magnitudes [2,10,11].…”

“…The electron pumping of Ne-like system was considered as a source for vacuum ultraviolet (VUV) lasing [1][2][3][4][5][6][7][8][9]. This is connected with the fact that the rates for electron collisional excitation from the 1s 2 2s2 2p6 ground state to the 1s2 2s2 2p5 3p higher lasing levels are greater than the rates for excitation from the ground state to the 1s2 2s2 2p5 3s lower lasing levels.…”

“…In the quasi stationary plasma, the population inversion between the 3p and 3s levels of Ne-like ions has been investigated [1,4]. However, only 27 levels belonging to the configurations 1s 2 2s2 2p6 , 1s2 2s2 2ρ5 3s, 1s2 2s2 2p5 3p, and 1s2 252 2p5 3d of these ions have been taken into account.…”