Investigation of the Laser-Like Effect in Powdered Luminophores

Abstract

It would be possible to develop purely chemical high power pulsed laser systems based on so called photon branchin chain reactions. In such type of reactions induced emission OF photons in the course of the chain reaction exceeds their expense to initiate the reaction. In our works a well-ar ued and fundamentally new way to bring about photon branc!in chain reactions, based on nonresonant interaction between I$ laser radiation and dispersed chemically actlve medja, has been advanced. It consists in introducing finely dispersed particles (e.g. passivated metal articles) into the active medium of HF or DF CO2 laser. TRe heating under the action of IR laser radiation causes the evaporation of particles and initiation of the chain reaction (Me t FZ = MeF t F). In this work we investi ated theoretically a ,pure chemical pulsed H2 F2 ampliyier with medium containing dis ersed particles of aluminium. We based on the authors’ own mul!ilevel model of HF laser allowed for the rotational nonequilibrium and anharmonicity of the HF molecules. Numerical calculations of chemical kinetics equations, vibrational relaxation e uations, heat balance e uation, equations for the temperature and radius of the aquminium particles subject t o evaporation in the HF laser field and the radiation transfer equations have been performed. We have found new dynamic regime of photon branching in dispersed medium of HF laser -wave re ime of the pro a ation of branchin chain reaction. In lhis regime efr%c?ive len t i ! h ? % the inpu? rlse absorption by dispersed particles is Par less than len t L of the HF amplifier. It was shown that output energy 07 the HZ F2 am lifier (L = 4 m) with the mixture pressure of 1 bar which utilizes aluminium particles with the concentration of &log cni’ and the diameter of 0.1 micrometers (h = 0.4 ml exceeds energy of the input radiation by 30 times. The ,research described in this publication was ,made ossible in part by Grant No.MXOOO from International Science F oundat ion. QThG20 Investigation of the Laser-like Effect in Powdered Luminophores