Studying on failure compensation in low-energy region of superconducting cavity in CAFe2

The high availability of Accelerator-Driven Sub-critical system (ADS) facilities poses a major challenge for the accelerators, which sets stringent requirements on the beam trip rate. However, beam trips caused by component failures in the low-energy region of the superconducting (SC) radio-frequency (RF) cavity are always a bottleneck for the long-term stable operation of high-power beams. In this paper, we present a compensation method. This method can be used to compensate for cavity faults that occur at low-energy (<10MeV). The compensation is achieved by rematching the beam with nearby components and compensating for energy using all cavities. The new Epeak and RF phases of the remaining components are calculated in the simulation environment using a multi-objective genetic algorithm. The compensation scheme is then tested on the super-heavy element research accelerator II (CAFe2). The experimental results show that the scheme can compensate for the energy, maintaining the same level as the normal operation status, while keeping the transmission efficiency >99.9%. The entire compensation process takes only 36s. This is the first compensation experiment in the low-energy region, and it demonstrates the feasibility of long-term stable operation.