<title>Sealed-off TEA CO2 lasers with pulse repetition rate up to 5 kHz for technological applications</title>

Abstract

ABSTRACTThe aim of this work was to investigate the influence ofplcsma-chemical reactions products, heat processes on theelectrode surface and the degree ofcoordination ofpump pulse generator on the forming conditions ofvolume discharge inthe working mixtures ofsealed-off TEA CO2 laser. The main factors, limiting the pulse repetition rate, were determined.Some versions ofsealedoffTEA CO2 lasers with the pulse repetition rate ofl-5 kHz and the pulse radiation energy of JO- 50 nil were realized. 1. iNTRODUCTIONIt is necessary to use laser pulses with A.10 pmof relatively low power and duration for some technological operations related to the films treating. But the pulse repetition rate must be 1 kHz or more to provide the required output of thetechnological equipment. The required 0.5 pulse parameters are achieved in the TEA CO2 lasers in free generation regime [1, 2]. But such lasers being sealed offyield very low pulse repetition rate -usuallyless than 100 Hz [2]. Limitation in the pulse repetition rate and in the service life of the sealed-off TEA CO2 lasers are caused predominantlyby the volume discharge localization as a result of the plasmachemical products accumulated in gas mixture. The maincomponent to initialize the volume discharge localization is molecular oxygen [2-4]. The molecular oxygen concentration