Measurements of the Gas Temperature in CO2–N2–He and CO2–N2–H2O–He Discharges

Abstract
The gas temperature has been measured at the axis of the positive column of a number of discharges commonly used for CO2 lasers. The measurements have been made with an interferometer. For the first series of measurements the tube is filled initially with 2‐Torr CO2 and 4‐Torr N2. Next, He is added in steps. In the second series the gas mixture also contains a small amount of H2O vapor. If the power input into the column is kept constant the gas temperature decreases when He is added.