Electrodes for gas discharge lamps

Due to the dominant role of discharge lamps in lighting applications and due to increasing diversification these lamps are still a research subject. Especially the quality requirements for the electrodes, which determine the life time, have been increased. Considering the relevance to lamp applications the main trends and aims of electrode research are specified. Common and different features of electrodes for low pressure and high pressure discharge lamps are pointed out. Special requirements during lamp start and stationary operation are discussed. Diagnostic measurements to determine the emission properties and to detect emitter transport from the electrode are presented.