Abstract
This paper deals with radiation transfer in a cylindrical high pressure HgTlI discharge for which local thermodynamic equilibrium can be assumed. The discrete ordinates method (DOM) is used to solve the radiative transfer equation. Calculations of concentration profiles of all species have been performed using a parabolic temperature profile and a constant mercury/thallium ratio throughout the discharge tube. The influence of thallium in HgTlI discharges on the spectroscopic parameters such as the spectral intensity, the radiative flux and the net emission coefficient is studied. A comparison of the calculated thallium line shapes with the measured ones shows good agreement.