hollow-cathode lamp

synonym: line source

https://doi.org/10.1351/goldbook.08486

Glow discharge source of spectral lines of an atom in which the cathode is made of the desired element.

Note:
It is often referred to as line source, as opposed to a continuum source.

Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 721 (https://doi.org/10.1515/pac-2019-0203)