| Abstract: | The energy demand for lighting is tremendous, and thus the reduction of costs by using more efficient light sources is an important challenge. Research and development in this field will also be essential in future. The application of new materials and procedures may lead to the development of new light sources. Some years ago, ceramic materials introduced a new quality of high pressure sodium lamps. Recently developed ceramic metal halide lamps have good future expectations. Sintered materials are used because of low costs. These materials are translucent but not transparent; that is why spatially resolved investigations are not possible. Basic research requires transparent discharge tubes. A special technique is introduced which allows the use of transparent sapphire. The present article shows that by selection of adequate materials and proper variation of essential parameters the sealing problem of a temperature firm, vacuum tight, electrically conducting connection can be solved. Especially for cases where experimental investigations on comparable bulk goods are not possible it is necessary to use this method in order to get experimental discharge tubes and employ optical diagnostics. |
