Speaker
Description
An improved TM020-mode RF cavity has been developed for the collider rings of the Super Tau-Charm Facility (STCF). By utilizing a higher TM020-mode for beam acceleration, this cavity has a lower R/Q = 83.5 Ω and a higher unloaded Q = 61300, compared with conventional TM010-mode cavities. These characteristics help reduce the required detuning frequency and significantly suppress coupled-bunch instabilities (CBIs) driven by the accelerating mode. The optimized cavity operates at 499.7 MHz and provides an effective accelerating voltage V_a= 0.6 MV. An elliptical choke is employed to reduce leakage power, achieving less than 2% power loss in the accelerating mode. In addition, harmful parasitic modes other than the TM020-mode are effectively suppressed by positioning the elliptical choke at the magnetic node of the operating mode. Through optimizations and thermomechanical analysis, the proposed cavity design meets the requirements of the STCF collider rings for beam currents up to 2 A. After fabrication, the cavity prototype was precisely tuned, and low-power RF measurements were performed. The measured results show good agreement with the simulations, confirming the performance of the improved TM₀₂₀-mode cavity.
| In which format do you inted to submit your paper? | Word |
|---|