Selective modulation of resonance lines in atomic spectra

摘要

1,019,846. Photo-electric analysis. COMMONWEALTH SCIENTIFIC & INDUSTRIAL RESEARCH ORGANIZATION. June 9, 1964 [June 12, 1963], No. 23879/64. Heading G1A. [Also in Divisions H1 and H4] A method for the selective modulation of resonance lines of an element contained in radiation emitted from an atomic spectral light source comprises producing an atomic vapour of the element by sputtering from a cathode containing the element, passing the radiation from the light source through the vapour, modulating the radiation passing through the vapour by modulating the sputtering current, and detecting the modulated radiation, e.g. in a photo-multiplier. The cathode is preferably a hollow cathode, open at both ends, the radiation passing axially through it, and the modulation of the sputtering current is preferably achieved by using an A.C. current.