Singlet oxygen in the low-temperature plasma of an electron-beam-sustained discharge

Abstract

To develop a nonchemical oxygen‐iodine laser (OIL), it is necessary to find an alternative (nonchemical) source of singlet delta oxygen (SDO) (molecular oxygen in the first electronically-excited state a 1 ∆ g ), which serves as an energy donor to atomic iodine in OILs. Such a source may be, e.g., an electric discharge. In order to achieve positive gain in a discharge, the SDO yield (which is defined as Y = [SDO]/([SDO] + [O 2 ]), where [SDO] and [ O 2 ] are the concentrations of singlet oxygen and unexcited oxygen, respectively) must exceed a certain threshold value Y th , which is a function of the temperature. Lasing in an electric-discharge OIL was observed for the first time in [1], where SDO was produced in an RF discharge and was then cooled in a supersonic gas mixture flow. In those experiments, the laser power reached 0.22 W at a gas mixture pressure in the laser cavity of 1.55 Torr.