An operator training facility at the Advanced Photon Source

The Advanced Photon Source (APS), a premier third-generation synchrotron radiation source, presently operates in top-up mode during most user run time. During top-up mode, charge is injected into the storage ring at approximately 2-minute intervals to stabilize the stored beam current to within 0.1%. Top-up mode requires the dedicated use of the entire APS injector system, severely limiting time available for operator training. The APS injector test stand (ITS) is presently configured to operate a ballistic bunch compression (BBC) RF gun, which uses three independently powered and phased RF cavities, and either a thermionic cathode or a photocathode. Operation of the BBC gun requires cavity phasing and input RF power selection analogous to the operation of a high-energy linac. In conjunction with the ITS beamline components (quadrupoles, dipoles, diagnostics, correctors), this provides an effective analog to the APS linac. Operators can therefore practice accelerator tuning and control methods with a live beam and real components, rather than simulations, while top-up operation is ongoing.