A collisional radiative model for mercury in high-current discharges

A collisional radiative model is presented for mercury discharges with elec tron temperatures between 0.75-2 eV and electron densities between 10(18)-1 0(20) m(-3). Such plasma parameters are encountered in a:number of modern l ight sources, such as mercury-operated induction lamps and the compact fluo rescent lamp. The analytical top model has been used, which allows the majo rity of the non-equilibrium levels to be taken into account implicitly. As a result, indirect ionization processes involving highly excited atomic mer cury states are taken into account in spite of the relatively low number of levels (19) which has been considered. The influence of higher atomic mercury levels on the ionization rate coeffi cient has been carefully analysed, and has been found to contribute signifi cantly. Furthermore, a consistent means of quantifying the production of ra diation by the plasma will be presented by introducing the specific effecti ve emissivities. These enable one to express the total radiated power in te rms of the densities of the transport-dominated states and the electron den sity and temperature. These coefficients, as well as the net coefficients o f ionization and recombination, will be presented and discussed, enabling. their usage in plasma transport models.