Influence of contaminants on the CO<inf>2</inf>electric-discharge laser

Abstract

In CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -He electric-discharge lasers, small concentrations of impurities may be present in the original gases, or new species may be generated by the discharge. In order to determine the effects of such impurities, controlled amounts of possible contaminants were introduced into the amplifier of a CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> probe-amplifier system. Small-signal gain was reduced in all cases when CO, O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> , NO, N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O, or NO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> molecules were added. It was found that less than 0.1 percent of NO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> or N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O markedly reduces the laser gain and alters the discharge impedance. A discharge model which describes a three-component positive-column plasma (electrons, positive ions, and negative ions) yields results consistent with the observations. The influence of attachment and detachment rates on molecular gas discharge characteristics and stability are studied.