Gyrotron microwave components cold testing

Abstract

Cold-testing of microwave components is required in high-power applications. It is a complementary method used together with full wave simulation software. Due to the cost and risks associated with the high-power emission, any errors in such devices should be detected and fixed before applying maximum output power. Additionally, when gyrotron is concerned, the resonator usually works with high-order modes. For this reason, conversion of the output power is required. All microwave components used to convert the radiation to Gaussian mode are built inside the gyrotron tube, which is under vacuum. Therefore, the cold testing and alignment of these components before tube assembly is a very helpful technique. The key element of the cold testing is a low-power microwave generator that is able to excite high-purity, high-order, azimuthal modes. To achieve this goal, a simple design method is proposed that allows one to create a TE mode generator, which can replace the gyrotron resonator tube during a cold test.