Initial Imaging of 7-GeV Electron Beams with OTR/ODR Techniques at the APS

The development of nonintercepting (NI) diagnostics for beam size continues to be of interest in the accelerator community. In the three rings of the Advanced Photon Source (APS) facility, we use optical and x-ray synchrotron radiation generated as the electron beam transits the dipole magnetic fields as an NI mechanism to image the beam during top-up operations. However, in the straight transport lines an alternate beam-size measurement method is needed. Optical diffraction radiation (ODR) is under investigation to monitor 7-GeV beam size and trajectory in the booster synchrotron-to-storage ring (BTS) beamline during top-up operations. We have performed our initial measurements with an Aluminum blade/mirror that served as an optical transition radiation (OTR) monitor when fully inserted into the beam and as an ODR monitor when the beam passed near the edge.