High-pressure gas discharge lamp with an incandescent cathode containing an active material

摘要

The invention relates to a high-pressure gas discharge lamp with an incandescent cathode containing an active material. Cathodes of this type are usually formed from a metal having a high melting point, usually from tungsten retaining elements and a layer applied thereto, which emits electrons. The invention relates, in particular, to an incandescent cathode which during operation is heated by the gas discharge, i.e. whose heating does not require a separate power source. The essence of the invention is an active gas discharge lamp whose cathode contains as the electron-emitting active material a compound of BaO-SrO-WO3 which significantly increases the service life of the lamps.