Great progress was witnessed during commissioning work on the 325MHz/3.2MeV CW (continuous wave) RFQ for Injector I of the ADS Proton Linear Accelerator Project on September 1st. With beam current above 10mA, the duty cycle reached 70%, average beam power climbed above 22kW, average radio-frequency power was above 315kW, and the transmission efficiency was higher than 95%. This is the first RFQ accelerator in China to operate under high frequency, high CW power and high beam duty cycle, and its average beam power at this frequency is among the world’s best.

The CW RFQ Injector I is a key piece of equipment for the ADS accelerator, as well as a high-tech frontier problem internationally, with its design frequency of 325MHz, output energy of 3.2MeV, and beam current of 10mA. An even harder problem is CW high power RFQ conditioning and combined beam commissioning, which are huge challenges for ADS group members. They have worked on shift around-the-clock, brainstorming unexpected problems as they happened. Plenty of discussions were made to improve to the commissioning method. Finally, beam duty cycle was improved to 70% while maintaining high transmission efficiency, with the output current above 10mA.

The conditioning and beam commissioning work on the RFQ has given ADS group members invaluable experience, especially in preparing for their future scientific tasks.

The IHEP machine shop, Division of Facilities Operation and Maintenance, and other related units also kindly provided support.