Speaker
Description
The storage ring of the High Energy Photon Source (HEPS) is driven by 166.6 MHz β=1 quarter-wave superconducting cavities. Five higher-order-mode-damped 166.6 MHz cavities were designed to provide a total of 850 kW beam power and to accelerate the electron beam to 200 mA. The beamline elements of the module were designed to meet the compact requirements. Given the large beam aperture of 505 mm to realize HOM damping, an exquisite clean assembly procedure was developed and demonstrated with excellent rf performance preserved from vertical tests to horizontal tests. Five cryomodules have been successfully assembled and horizontally tested. The cavity’s Q0 at the design voltage of 1.2 MV reached 1.5e9~2.1e9 at 4 K corresponding to 5~7 W dynamic heat loads in the horizontal tests, comfortably exceeding the design goal. Field emission was less than 0.13 mSv/h during the entire test up to a rf voltage of 1.6 MV, equivalent to a peak electric field of 43 MV/m. Subsequently, five modules were installed in the HEPS tunnel. A beam current of 100 mA was successfully achieved in September 2025. This work represents the first successful implementation of superconducting QWRs as the main accelerating system for a high-current storage ring, thereby extending their application limits from the conventional use in low-beta accelerators to high-current electron storage rings, and establishing them as a proven technology for future high-performance light sources.
Funding Agency
National Natural Science Foundation of China (Grant No. 12475166, 12275285, and 12275287). High Energy Photon Source, National Development and Reform Commission of China.
| In which format do you inted to submit your paper? | LaTeX |
|---|