<title>Potential IF chemical laser</title>

Abstract

ABSTRAFThe electronic transition IF B3 H(O)--> IF X1 is accompanied by a radiative emission in the vicinity of 625 nm. The possibility of using this transition in a chemical laser through direct production of the B state is estimated. A computer code has been developed and applied to a kinetic scheme also described. It has been observed that a population inversion between IF B H(O), v'=O and IF v"=5 can be achieved. IF B is obtained by mixing I (2 P 3/2) plus F (2 P 3/2) with 02 (1 Atomic species are produced directly by only one combustion followed by frozen expansion. A set up is proposed to demonstrate the laser effect. The characteristic time of mixing and the population inversion lifetime are so close, that an optimization of the injection and mixing conditions is necessary. In a first experimental step to demonstrate laser effect, the iodine planar laser induced fluorescence technique allowing the visualization of mixing flows was used to qualify and to optimize the injection device. BASIC CONCEPTMany research projects have been developed to achieve a laser effect in the visible range of the electromagnetic spectrum by chemical pumping. The 10 j.ts radiative lifetime and the acceptable value (0,1995) of the Franck Condon factor [1] for the transition IF B 311(0+), v'=O --> IF X1, y't5 &e favorable values, so that a laser effect can be expected if a population inversion can be achieved by chemical pumping. Davis [2] has already demonstrated a laser effect in the red band by optical pumping on electronic transitions between IF B H(O) and IF Raybone [3,4] proposed a method for producing IF B H(O) from excited atomic iodine I (2 P 1/2 and atomic fluorine in the ground state F (2 P 3/2) A three-body process (1) and a two-stage mechanism (2a) et (2b) are involved.