Design of a water-cooled tube for high-power and long-pulse radio frequency ion source

Hence, the cooling circuit of the tube is designed and estimated through a fluid-thermal analysis. The water inlets with tangential injection direction are located inside the metal flanges. Such a design can induce a swirling flow around the tube, which can cause a more uniform temperature distribution and a lower peak temperature on the tube.

In order to control the stress along the joints between the metal and the ceramic, the Kovar alloy (an iron-nickel constant expansion alloy) is chosen for the metal flanges, which has a similar thermal expansion coefficient with the ceramic. The thermo-structural analysis indicates a tolerable thermal stress on the ceramic layers of the designed tube under a uniform heat load of 30 kW.