Multipacting analysis of power coupler for SC cavity

A power coupler is designed for the SC cavity. The multipacting analysis of the coupler is carried out by a code developed in house. The code calculates the enhanced counter function to evaluate the resonant trajectories. An emission model for secondary electrons is assumed and the emission energy and angle of secondary electrons are assigned by a Monte Carlo method. The multipacting bands are observed at the power levels of 0.3 MW–1 MW. DC bias voltages in the range of −8 kV to −10 kV are required to quench the multipacting completely.