China successfully develops its first double-spoke superconducting cavity cryomodule

Designed a high-performance double-spoke superconducting cavity.

The research team implemented comprehensive electromagnetic and mechanical optimizations on the double-spoke superconducting cavity, achieving three key improvements: reduction of peak electric field during normal operation, suppression of multipacting effects, and enhanced manufacturability. A dedicated Buffered Chemical Polishing tooling system was developed for double-spoke superconducting cavities with complex structures, ensuring uniform acid etching and achieving high Q-values (Q > 3.4×10¹⁰ @ Eₐ_cc = 9 MV/m).

Developed a high-performance cryomodule

The double-spoke cavity cryomodule employs carbon fiber tie rods to suspend the superconducting cavities within the cryostat, effectively reducing heat leakage while allowing convenient positional adjustment of the cavity in cryogenic environments.

Development of the Cooling Procedure for Superconducting Cavity Cryogenic System

Based on the significant correlation between cooling rate and Q-value observed during vertical testing of double-spoke superconducting cavities, an optimized cryogenic cooling protocol was developed with precisely controlled cooling rates, to maximize Q-value preservation.

The complete study is accessible via DOI: 10.1007/s41365-025-01716-1.

Nuclear Science and Techniques (NST) is a peer-reviewed international journal sponsored by the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. The journal publishes high-quality research across a broad range of nuclear science disciplines, including nuclear physics, nuclear energy, accelerator physics, and nuclear electronics. Its Editor-in-Chief is the renowned physicist, Professor Yu-Gang Ma.