ATCA-based Control System for Compensation of Superconducting Cavities Detuning Using Piezoelectric Actuators

The linear particle accelerators use superconducting cavities working with high operating gradients. The electromagnetic wave, transferred to the cavity as a set of successive pulses, causes mechanical stresses inside the cavity. Therefore, the resonance frequency of the cavity is significantly modulated, which may lead to cavity detuning in range of hundreds of Hz. The piezoelectric actuators are commonly used for the compensation of the cavity detuning. The paper presents the prototype piezo control system which is capable of compensating 32 cavities simultaneously. Moreover, the first tests of the system in FLASH (Free-Electron Laser in Hamburg) accelerator are presented. The described system is ready to be applied to the next version of LLRF (Low Level Radio Frequency) control system based on ATCA (Advanced Telecommunications Computing Architecture) architecture.