Articles techniques et présentations

High-intensity discharge (HID) lamps are energy-efficient light sources with excellent color qualities. A three-dimensional model of a low-wattage lamp, which includes plasma, electrodes, and burner walls, was developed in COMSOL Multiphysics®. Most parameters appearing in the coupled differential equations of the model, such as viscosity, thermal and electrical conductivity are temperature-dependent. In order to investigate the influence of material properties and the plasma pressure on the temperature distribution and the corresponding Eigenfrequencies, a sensitivity analysis was performed. The experimental validation was conducted by measuring the voltage drop between the electrodes at different driving-frequencies. The sensitivity analysis shows that precise material data is crucial for the significance of simulation results. The plasma reacts more sensitive to changes of the electrical conductivity than to variations of the pressure.