Preliminary Beam Tests at REX for an Automatic Cavity Phasing Routine at HIE-ISOLDE

The HIE upgrade at ISOLDE will use 32 independently phased superconducting quarterwave cavities, which will impose new demands on the operation and set-up of the linac. The large range of different radioactive species and the broad experimental programme means that the same beam species and energy are rarely studied twice, and the accelerator must be re-tuned for each experimental run. In order to expedite machine set-up it is foreseen to calculate and set automatically the cavity phases when the operator inputs the desired beam energy and A/q of the beam species. In this note we explore our understanding of the REX rf system and test our beam dynamics calculations with two independently phased 7-gap split-ring cavities.