Electron Beam Pumped Ultraviolet Light Sources

摘要

Electron collision is the basic process in all light sources using gases as the light emitting material. In discharge lamps the electrons are accelerated in an electrical field until their energy is high enough for exciting the atoms or molecules in the gas. Although already studied as early as 1894, an alternative way for collisional excitation of gases in which the electrons are first accelerated in the vacuum and then sent into the gas, had so far never been used in lighting devices. This paper describes a project in which we develop the technology for compact, portable ultraviolet light sources based on the excitation of gases by electron beams which are formed in a vacuum section of the source and injected into the gas through a thin membrane. The basic processes in such light sources are studied in parallel with the technological development. Novel light emitting systems are being developed, studied and optimised. The new method is well suited for exciting high lying levels in light emitting species. In particular, ultraviolet excimer light sources can be easily realized with the technique described here. A schematic drawing of the light source concept is shown in Fig. 1.