The domestically-made superconducting spare cavity system, a key equipment for BEPCII project, was reviewed at IHEP in Beijing on April 18^th. The review committee was chaired by Prof. Chen Jiaer (Peking University) and consists accelerator experts from Peking University, University of Science and Technology of China, Tsinghua University, Shanghai Institute of Applied Physics (CAS) and IHEP.

The project leader, Prof. Pan Weimin, presented the development and operation of the BEPCII spare superconducting cavity system. Finally Prof. Liu Kexin from Peking University announced the beam operation results of the cavity system on behalf of the committee.

The committee reviewed and acknowledged the previously conducted self-testing results of the cavity system and the employed methodologies for beam-based measurements. During the BEPCII high-energy physics run, the radio-frequency accelerating voltage in the cavity reaches 1.53 MV with a stability better than ±0.43% in amplitude and ±1° in phase.

Accelerating electron beams for 6 months, the domestically-made spare superconducting cavity system has been running well and achieved same performance of the similar foreign equipment. This is the first time that a domestically-made superconducting cavity has been accelerating beam in routine operation replacing a foreign cavity in large scientific facilities in China. This indicates that China has made significant progress in domestic manufacturing of high-tech accelerator equipment.

The success of development and integration of the BEPCII spare superconducting cavity system indicates that China has made great breakthroughs in the 500 MHz superconducting cavity technology, and is among a few countries in the world which are able to develop such superconducting radio-frequency systems.

During the key technology R&D, system integration, horizontal tests and beam operation of the BEPCII 500 MHz superconducting cavity system, IHEP has gained rich experience in realization and operation of such system, and also trained a team of physicists and engineers with comprehensive expertise. These have laid an important foundation for domestic manufacturing of key superconducting radio-frequency equipment and future development of the technology.