UV and visible emission processes in a moly-oxide discharge

Summary form only given, as follows. Due to the hazardous material designation of spent fluorescent lamps on board naval vessels, the Naval Research Laboratory has been investigating alternative lighting concepts which are free of mercury. A moly-oxide discharge driven by an inductively coupled RF coil at 13 MHz emits a broad spectrum in the visible range with strong line emission from the quintet spin levels of the Mo atom near the peak of the photopic curve. One limitation of such a discharge for direct white light applications is the near UV emission from the Mo septet resonance lines between 300 and 400 nm. Analysis of the excitation processes and channels for both the visible and UV emission will be presented based on a Boltzmann model for the electron energy distribution function and detailed atomic physics calculations for the cross sections. The results indicate that a Mo partial pressure of -10 mTorr or more will render the resonance lines optically thick and concurrently increase the visible emission. Calibrated spectroscopic measurements throughout the UV and visible region will be reported as a function of power and pressure and compared, through actinometry, with the theoretical simulations.