Speaker
Description
The development of high-repetition-rate superconducting linear accelerators for advanced light sources imposes stringent demands on the performance of the Low-Level Radio Frequency (LLRF) control system. This report presents the design, implementation, and operational results of a high-precision LLRF system developed for the Dalian Advanced Light Source (DALS) injector—a 1 MHz superconducting linac. The system employs a digital feedback architecture based on a field-programmable gate array (FPGA), enabling high-speed I/Q modulation and demodulation, vector summation, and low-latency feedback control to address the narrow bandwidth challenge posed by superconducting cavities with loaded quality factors up to 4.3×10⁷ (half-bandwidth ~15 Hz). High-resolution piezo actuators are integrated for active cavity tuning. During commissioning in August 2025, the system successfully stabilized ten superconducting cavities, supporting beam operation at over 100 MeV, 1 MHz repetition rate, and 0.1 mA current. Closed-loop amplitude and phase stabilities of better than 0.02 % and 0.02 ° were achieved per cavity, with total voltage maintained steadily at 110 MV. The results demonstrate the system’s robustness and precision, providing a valuable reference for future LLRF systems in next-generation high-repetition-rate light sources.
Funding Agency
the National Natural Science Foundation of China (Grant No. 12405221)
| Paper status | Proceeding files received |
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