Demonstration of resonant fluorescence in Mo VII induced by Mo XII for possible lasing near 600 Å

We present data of experiments on the resonant photopumping of Mo vii by Mo XII as a method of generating a coherent vacuum UV source near 600 Å. The experiment is based on a scheme in which the 4p⁶ − 4p⁵ 6s transition in Mo vii is resonantly photopumped by the 4p 2P_3/2 − 5s²S_1/2 transition in Mo XII. Results of the laser-produced plasma experiments show the successful enhancement of the population of the Mo vii 4p⁵6s upper lasing level when Mo vii is pumped by an adjacent Mo XII plasma. No enhancement was seen in a control experiment in which the Mo vii plasma was irradiated by a Zr x plasma. Finally, estimates of the relative population densities between the 5s and the 6p levels are given to show that the experimental conditions are close to those needed to produce a population inversion.