Plasma Chemistry and Plasma Processing, Vol.23, No.2, 371-387, 2003
Monte Carlo simulation of radiation trapping in Hg-Ar fluorescent discharge lamps
The line spectra of emitted resonance radiation from mercury and the effective decay rates of the Hg 6(3) P(1) and 6(1) P(1) levels in mercury-argon discharges are simulated by a Monte Carlo method. The hyperfine splitting, the natural isotopic composition, collisional transfer of excitation, foreign gas collisions and quenching are considered to describe in detail the 253.7 nm and 184.9 nm lines. The calculations are performed for Hg vapor densities corresponding to coldest spot temperatures of 5-100degrees C, and discharge parameters typical for fluorescent lamp operation. The densities of the Hg 6(3) P(1) and 6(1) P(1) levels are consistently estimated by means of a set of balance equations for the Hg 6(3) P(0), 6(3) P(1), 6(3) P(2), and 6(1) P(1) excited states. The resulting uv radiation output of the discharge is then estimated for a tube radius of 18 mm, argon pressure of 400 Pa, discharge current 0.4 A, and wall temperatures of 20-80degrees C. The results obtained show a good agreement as compared with published experimental data.
Keywords:Monte Carlo simulation;resonance radiation;trapping;mercury-argon discharge;low pressure;emission spectra;decay rates;uv output