Fabrication and Utilization of a High-Power Microwave Supply for Electrodeless Discharge Lamps and other Spectrochemical Emission Sources

A study of the factors influencing the performance of a microwave-induced discharge shows that the analytical utility generally increases as the applied microwave power is increased. The fabrication of an easily used high-power system (500 W) is described; the system is used to excite electrodeless discharge lamps of relatively high-boiling species, multielement lamps, and an atmospheric-pressure flowing plasma. The system has been used to study vaporization phenomena in a cadmium electrodeless discharge lamp. The ground-state atom population, as measured by absorption, appears to be directly related to the thermal (wall) temperature.