On the atomic hydrogen line shapes in a plane-cathode obstructed glow discharge

Abstract

In order to investigate the charge-transfer reaction between Ar+ and H2 which is important for the shape of hydrogen Balmer lines and to clarify the pathway of this reaction, the study of charge-transfer reaction Ar+ + Cu in argon-copper, argon-copper-hydrogen and neon-copper-hydrogen plasma of a plane-cathode hollow anode glow discharge was undertaken. It is shown that Ar+(2P1/2) + H2 reaction is the main source of H2+ ions in our plasma. Study of the influence of cathode material on the shape of hydrogen Balmer lines clearly shows that the lower part of these lines emitted by the discharge in hydrogen and in the mixture of hydrogen and neon are appreciably broadened. Analysis of these profiles indicates that scattering and excitation of hydrogen on the sputtered cathode material in the vicinity of the cathode plays an important role in line shape formation. © 1994 IOP Publishing Ltd.