Operational Experience with Coupled-Cavity Structures in a High Duty Factor Accelerator

The Chalk River Electron Test Accelerator is a facility to study beam behaviour in a multi-tank accelerator and to develop control systems for high power operation. Two standing-wave structures have been operated at energy gradients of 0.75 MeV/m and their accelerating fields held constant under 50% beam loading. During start-up, the control systems must accommodate resonant frequency shifts exceeding ten bandwidths in both of the dissimilar structures and their resonant frequencies must differ by less than a tenth of a bandwidth before locking to the accelerator frequency. The central mini-computer controls the run-up and among other things controls the structure temperature.