The cylindrical configuration of the cathode tends to concentrate the radiation in a limited region of the metal tube; this design also enhances the probability that redeposition will occur at the cathode rather than on the glass walls.
The efficiency of the hollow cathode lamp depends upon its geometry and the operating potentiaL High potentials, and thus high currents, lead to greater intensities. This advantage is offset somewhat by an increase in Doppler broadening of the emission lines from the