Compact Sulfur Lamps Operated By Antenna-excited Microwave Discharge

摘要

An antenna-excited microwave discharge (AEMD) lamp has shown attractive properties compared with conventional AC discharge or electrodeless microwave discharge lamps. This paper concerns a compact AEMD sulfur lamp with such a unique structure that a pair of antennas are covered with thin quartz glass. It is found that a stable plasma is generated between the antennas regardless of whether the antennas are coated by dielectrics. The microwave power supplied into the AEMD sulfur lamp is approximately 50 W, which is much lower than that of conventional sulfur lamps that require higher microwave power to start and maintain the discharge. Observed spectral features showed that the radiant power distribution was in the UV range at low sulfur pressure and shifted to the visible light range with increasing sulfur pressure. Finally, the possibility of obtaining a compact AEMD sulfur lamp is discussed.