Metal halide discharge lamps under micro gravity conditions

Abstract

Metal Halide Lamps are very efficient light sources based on a mercury plasma arc with metal halide salt additions. In spite of their high efficiency the lamps suffer from colour separation and instabilities, which currently hinders a large-scale use. These phenomena are caused by a complex interaction of convection and diffusion flows in the plasma. In order to unravel the various contributions experiments under micro gravity have been performed, where convection is absent. In this contribution the experiments as well as some first results are presented