Thermal analysis of an S-band output RF vacuum window

The RF loss power of a dielectric disk for an Sband output vacuum window is calculated in terms of the transmissions of the cylindrical-waveguide TE₁₁-mode together with the cylindrical-waveguide TM₁₁-mode. The warm-up process of the window due to the RF loss is simulated using ANSYS code. The temperature distribution and the thermal stress pattern of the window structure are also obtained. The results show that, the maximal temperature gradient of the window disk may exceed its heat-resistant limit, which increase the possibility of window cracking.