Development of a 140 GHz 50kW Gyrotron in IAE

Aiming for future electron cyclotron heating application in plasma fusion, a 140GHz 50kW gyrotron has been under development in Institute of Applied Electronics, China Academy of Engineering Physics as the first stage. The gyrotron is designed by the self-developed codes and employs a BN water-edge-cooling window. An updated prototype based on 2018 version has been fabricated and tested. In the experiment, a Gaussian beam of 20kW for 60s continuous wave has been achieved. The higher power operation results are 30kW/20s, 50kW/30s with duty cycle of 60%. The pulse duration extension and power enhancement were hindered by the outgassing of BN window due to overheating.