Характеристики излучения короткодуговых ксеноновых газоразрядных ламп высокого давления

Abstract

The paper is devoted to the study of changes in characteristics of ultra-high pressure short-arc xenon lamps when a tungsten layer is sprayed onto the quartz shell, as a result of heating and local electrode erosion. The paper analyzes the mechanisms of phenomena occurring in the super-high pressure xenon discharge and the cathode spot, which affect the sputtering of the electrode material. The main negative effects of tungsten deposits appearing on the lamp shell inner surface are considered: a decrease in the optical transparency and mechanical strength of quartz glass, an increase of the bulb temperature, a change in spectral characteristics and spatial distribution of radiation of a gas-discharge lamp. The original method developed for studying the parameters of radiation of a gas-discharge lamp and based on the superposition of the optical axis of the photometer with the axis of the lamp passing through the cathode spot and the considered shell segment, transparent or sprayed, allowed us to compare radiation characteristics of the lamp without changing the plasma parameters. The thermodynamic analysis carried out within the research confirmed the absence of chemical interaction of tungsten layer with quartz glass. Spectral distribution of xenon discharge radiation in the visible and IR ranges is different for a transparent bulb and the bulb with a tungsten spot, which is due to the size of tungsten layer particles on the lamp bulb. A study of spatial distribution of radiation from a gas-discharge lamp showed a decrease in the intensity of radiation in a solid angle bounded by a tungsten spot. At the same time, in this region, there was observed an increase in the temperature of the quartz shell, leading to the appearance of a longitudinal gradient of the temperature field of the gas-discharge lamp.