CO2 dissociation in sealed rf-excited CO2 waveguide lasers

Abstract

A mass spectrometer has been used to study the gas composition in a sealed rf‐excited CO₂ waveguide laser during operation. CO₂ dissociation levels, at 53% to 71%, are similar to those reported for dc‐excited waveguide lasers and substantiate prior measurements on rf‐excited discharges. The degree of dissociation decreases with increasing pressure and xenon content, but increases as the proportion of helium in the gas mixture is increased. Dissociation has been found to be insensitive to the rf input power per unit discharge length over the range of 2.7 to 4.7 W/cm. This is believed to be the result of increased rates of water vapor outgassing at higher input power levels.