Multibunch BNS Damping and Wakefield Attenuation in High Frequency Linacs

In high frequency linacs, where the wakefields are strong, the stability of a train of bunches is critical. It was therefore important for the Compact Linear Collider study (CLIC) to investigate numerically and theoretically this question. Basically, two methods of controlling beam break up have been considered; firstly a multibunch generalization of the BNS damping principle and secondly the attenuation of the long-range fields as it results from damping or staggered tuning of the accelerating sections. Simulation codes have been written for both checking the theoretical predictions and investigating the requirements associated with a possible application to the CLIC main linac.