POSITIVE-COLUMN HG-RARE GAS-DISCHARGE MODEL APPLICABLE TO COMPACT FLUORESCENT LAMPS

Previous models of mercury-rare gas positive column discharge have shown good agreement with experimental observations typical of fluorescent lamps. Nevertheless, these models did not consider effects of a non-maxwellian electron energy distribution, associative ionization and volume recombination. There is growing evidence, however, that these effects can be important in many low pressure discharge applications. Particularly, one such application appears to be the high loaded compact fluorescent lamp. We have developed a calculational model which takes into account the above processes. This model and the relevant computer program allows one to calculate all parameters of the positive column for mixtures of Hg plus Ne plus Ar and Hg plus He plus Ar. The calculational model is based on the equations of the population, ionization and energy balance averaged over the tube cross-section. The electron energy distribution function has been represented by an expression obtained on the basis of approximate analytical solution of the Boltzmann equation. This expression takes into account depletion of the distribution tail due to inelastic collisions dependent on the mercury atom and electron number densities.