ABSTRACT
We report here the use of measurements of the time dependence and intensity of emission of rare-gas spectral lines in the negative glow as a cathode fall diagnostic in fluorescent lamps. For argon buffer gas, the relevant energy levels and spectral lines are shown in Fig 1. The 420 nm violet line is emitted in a transition between the 5p state at 14.50 ev and the metastable state at 11.55 ev. The 811.5 nm infra-red line is emitted in a transition between the 4p state at 13.08 ev and the metastable state at 11.55 ev.
