RF Impedance of the Accelerating Beam Gap and Its Significance to the TRIUMF RF System

The RF system at TRIUMF is now operating with the highest Q, the lowest RF leakage into the beam gap, the best voltage stability, and the lowest resonator strongback temperatures ever measured since it was first put into operation. This paper describes the calculation of the RF impedance of the beam gap and its correlation to the RF problems encountered, which eventually led to modifications to the flux guides and resonator tips to accomplish the improved operation of the RF system.