Abstract
In recent years, a high-power millimeter wave source, a gyrotron capable of oscillating multiple high frequencies has been developed, and the development of a dummy load that supports multi-frequency operation is an issue. We have designed and manufactured a short-pulse dummy load that directly absorbs millimeter waves of different frequencies of 70 GHz and 28 GHz up to 300 kW with cooling water in the transmission line. Measurement results show that the power estimation in the transmission is reliable with high sensitivity at both frequencies. The dependence of the water temperature evolution on the operation conditions has been evaluated through thermal-fluid analysis. The difference in the beam shape does not affect the temperature evolution due to the heat exchange with the waterway, indicating that the same operation can be performed even when operating at different frequencies.
https://ror.org/0418a3v02 
