Source:Journal of Physics D: Applied Physics 38, accepted for publication (2005)
This paper is concerned with the numerical simulation of High-Intensity Discharge (HID) lamps, focusing on the influence of pressure, current, and electrode gap on plasma, anode, and cathode properties. The interaction between electrodes and plasma is taken into account. Comparisons between experimental findings and numerical results show that the observed increase in the total lamp voltage caused by an increasing lamp current is a superposition of an increasing lamp voltage due to an increasing pressure (caused by the increasing lamp current) and a decreasing lamp voltage due to the increasing lamp current (if the pressure would be constant). Furthermore, the numerical results reveal that the plasma potential in the whole plasma strongly depends on the electrode gap and that even the electrode temperature and the arc attachment to the electrodes in influenced by the size of the electrode gap.