Orbit correction techniques for a multipass linac

The CEBAF accelerator includes a linac section which accelerates multiple beams with different energies. Problems arise when performing orbit correction, due to the fact that correction of higher energy passes disturb lower energy trajectories. Therefore, a perfect orbit correction cannot be obtained for all energy beams at the same time. We present methods and performance (using simulation results) for performing orbit corrections in such a system. Limitations to the correction method are also addressed. 2 refs., 5 figs