The effect of small quantities of hydrogen on a glow discharge in neon. Comparison with the argon case

In order to gain an insight into the numerous effects caused by the additio n of hydrogen to an argon glow discharge, comparison experiments have been made with peon as carrier gas. In some cases the effects are diminished or even disappear. Using various bulk samples, such as copper, steel and titan ium, sputtered in al neon glow discharge, the intensities of the analytical lines are affected by the presence of hydrogen indifferent ways from argon ; the dependent parameter (the discharge current in this, work) and the spu ttering rate vary less than in argon. The crater shape and roughness are al so affected and these effects are discussed qualitatively. Probably the mos t important spectral feature caused by hydrogen in the case of a discharge in argon is the emission of a continuous background. This does not appear i n neon under similar discharge conditions and only weakly at high hydrogen concentrations. This supports the suggestion, made in previous work, that a n effective quenching process of the argon metastables (11.55 and 11.72 eV) is Penning excitation of the hydrogen molecules, and subsequent decay to a repulsive state with emission of the continuum; in neon the energy match d oes not occur. It was found with neon, as with argon, that similar features occur as when hydrogen is introduced in different ways into the glow disch arge: as a molecular gas contamination eras a constituent of the sample. Gl ow discharge mass spectrometry (GD-MS) experiments carried out with both ar gon and neon support the results obtained by optical emission spectrometry (OES) and provide further relevant information.