Modeling the millimeter-wave beam joining of ceramic tubes

Summary form only given. The high power beams that can be generated by CW gyrotrons represent a promising energy source for high-temperature processing of materials. To effectively use these sources, modeling of the beam interaction with candidate materials, e.g., ceramics, can give significant insight into the field and power distribution within the material. From these field assessments, heat generation with the material can be determined and coupled with thermal transfer analysis, heating and heat flow can be assessed. In this paper, a method of evaluating the time-dependent temperature profile of ceramic cylinders was discussed. Both solid cylinders and tubes have been analyzed. For the tubes, the region is treated as a composite system comprised of cylinders of dielectric material having different dielectric and thermal properties. Theoretical results was compared to qualitative results from current research into the joining of ceramic cylinders that use the 83 GHz gyrotron based material processing system at NRL.