Thermionic emission from barium tungstate emitters and its effect on mercury lamps
Abstract
The use of barium tungstate as the emitter substance for high pressure mercury lamp electrodes is investigated. Barium tungstate incorporating strontium and calcium was combined with aluminum oxide or yttrium oxide, and the thermonic emission and evaporation rate determined. The thermionic emission and evaporation rate were investigated in relation to lumen emittance and starting voltage in high pressure mercury lamps utilizing the emitters. Deterioration in luminous flux was dependent on the rate of evaporation, and the work function of the emitters was dependent on the starting voltage of the lamp.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- January 1981
- Bibcode:
- 1981STIN...8128345W
- Keywords:
-
- Barium Compounds;
- Electric Potential;
- Evaporation Rate;
- Mercury Lamps;
- Thermionic Emission;
- Tungstates;
- Aluminum Oxides;
- Calcium Compounds;
- Electrical Measurement;
- Electrodes;
- Lumens;
- Strontium Compounds;
- Work Functions;
- Yttrium Oxides;
- Electronics and Electrical Engineering