ABSTRACT
INTRODUCTION New types of fluorescent lamps, including both compact and electrodeless lamps, utilise Hg-
rare gas discharges at much higher power densities than standard fluorescent lamps. Several plasma physics phenomena, which are relatively unimportant in the plasma of standard fluorescent lamps, become important in high power density Hg-rare gas discharges. Numerical models are playing an increasingly important role in the further development of fluorescent lamp [1-9]. Plasma models, which have been optimised under standard fluorescent lamp conditions, have not yielded agreement with experiments on high power density Hg-Ar discharges [10]. Radial cataphoresis, electron-ion scattering, ladder like ionization, and deviations from the fundamental spatial mode for both ambipolar diffusion and radiation transport are some of the plasma phenomena which become important at high power density.
