Intensity of Ar spectral lines in an Ar-O 2 glow discharge

Abstract

Measurements of relative intensities of spectral lines and of plasma parameters have been carried out in an Ar-O 2 d.c. glow discharge under the following conditions: gas pressures of 1, 2 and 3 torr and partial pressures for O 2 of 0, 0.01, 0.02, 0.05 and 0.1 torr. Many of the Ar line intensities decreased when O 2 was added, while some were enhanced. Enhancement of the 6677A and 7504A lines has been most notable. The number density of metastable Ar atoms is decreased when O 2 is added. Upon addition of O 2, the electron temperature is decreased and the electron density increased, except at a gas pressure of 1 torr; the electric field strength in the positive column is also increased.