Modern Dielectric Materials for Output Windows of High-Power Microwave and Terahertz Sources

Analysis of dielectric properties of several materials, BN, AlN with BN additive, crystalline quartz, MgAl 2 O 4 spinel, 6H-SiC in the millimeter and submillimeter (terahertz) ranges, is presented. Basing on the experimentally measured dielectric losses of these materials and on their thermal and mechanical properties, we made a calculation to estimate the maximal achievable output power that can be transmitted through disks made of such materials. Prospects for using these materials for gyrotron barrier window production are discussed.