THE MULTIPACTORING- FREE RF CAVITY OF THE DAΦNE ACCUMULATOR

The performance of the RF cavity resonators may be limited by the resonant electron discharges or multipactoring. This phenomenon can take place in under vacuum RF devices, it makes difficult the cavity conditioning, causes RF losses and prevents to reach the operating voltage range. The RF cavity of the DAΦNE Φ-Factory Accumulator Ring [1], is designed to operate at 73.65 MHz with a maximum accelerating voltage of 250 kV peak and consists of a reentrant λ/4 coaxial resonator. The shape has been carefully studied to achieve a multipactoring- free cavity. The simulation of discharge trajectories due to resonant electrons in cavity resonators having rotational symmetry has been carried out for this RF cavity with the computer code Newtraj [2]. Numerous code outputs are presented and discussed in this paper. The cavity power tests have been performed successfully; theoretical and experimental results, together with the design criteria, are presented