Development of advanced cavity cooling systems for a 170 GHz, 2 MW coaxial cavity gyrotron

In high-power fusion gyrotrons, the maximum heat-load on the wall of the interaction section is in the order of 2 kW/cm2, which is the major limiting technological factor for output power, efficiency and pulse-length of the tube. The ongoing gyrotron development demands a very effective cavity cooling system for stable and optimum gyrotron operation. In this work, the thermal performance of a mini-channel cavity cooling is numerically investigated using the ANSYS Fluent® code-package. The influence of the various physical and operating parameters on the cavity cooling efficiency is systematically studied for a 170 GHz, 2 MW coaxial-cavity gyrotron and an optimized heat sink design is proposed. A mock-up test set-up is also developed to experimentally validate the simulation results.