An Interferometric Study of a High-Intensity, Hollow-Cathode Source

Measurements of the profile of the λ 3247.5-Å copper resonance line emitted from a high-intensity, hollow-cathode source of the Sullivan—Walsh type have been made using a pressure-tuned, Fabry—Perot interferometer. It is found that the enhanced intensity from this source compared with that from a conventional hollow-cathode source is accompanied by a considerable decrease in the self-absorption of the resonance line within the source. The line-profile measurements together with measurements of the decay of the resonance radiation on switching off either the hollow-cathode discharge or the auxiliary discharge are in qualitative agreement with the hypothesis that the radiation is emitted partly from the hollow-cathode discharge and partly from the auxiliary discharge.