Thermochemische Untersuchungen zur Hochtemperaturkorrosion in Metallhalogenid-Entladungslampen

Halides of lanthanide are essential components of filling of modern metal halide discharge lamps. These filling made in the arc a line-rich emission spectra in visible region. However this filling are corrosive to lamp vessel and electrodes. For guarantee the high quality demands to modern light sources, it is necessary to understand the processes during lamp operation. To optimise metal halide lamps to there properties, process behaviour and duration of live there carry out model calculations. But this model calculations are only workable if all parameters of lamp process are known. But the mechanism of corrosion in metal halide lamps are up to now not very known. Aim of this work is by using Knudsen effusion mass spectrometry to simulate the corrosion processes between lamp filling and wall material in metal halide lamps and to open the corrosion processes to thermo-chemical measurements. This work supply a contribution of knowledge of transport processes of SiO_2 along the wall in quartz-glass discharge vessels. These transport processes are up to now neither quantitatively nor qualitatively understand. In this work are the supposed formation of gaseous silicon-oxy-halides at first time proved, thermo-chemical measured and opened to thermo-chemical calculations. (orig.)Dissertation submitted by Karwath, T., 80 refs.Available from TIB Hannover: RA 831(3725) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman