Multipacting study of power couplers for the CSNS DTL.

There are four taper ridge waveguide couplers with characteristic impedance of 50 ohms operating in pulse mode at China Spallation Neutron Source (CSNS) Drift Tube Linac (DTL) section. Multipacting (MP) in couplers may be a factor limiting the steady operation of the accelerator. In this paper, MP barriers in the critical area of the coupler are estimated according to the parallel-plate model firstly. Second, we present a detailed numerical simulation results obtained by the TRK and PIC Solver in CST PS Studio. Furthermore, MP zones encountered during the conditioning process are performed. Finally, a good agreement of the analytical predictions, the numerical simulation results and the experimental data have been found. [ABSTRACT FROM AUTHOR]