Planned optical diagnostics for the APS low-energy undulator test line

At the Advanced Photon Source (APS), an alternate configuration of the injector linacs (low-energy undulator test line) using an rf gun as the source is projected to provide low normalized emittance electron beams (/spl epsi//sub n//spl sim/5/spl pi/ mm mrad). In order to characterize such beams, the present intercepting Chromox screens with limited spatial resolution and temporal response are being complemented by optical transition radiation (OTR) screens at selected positions in the beamline to provide sub-100 /spl mu/m spatial resolution and sub-ps response times. Both gated cameras and streak cameras will be used to measure the beam properties. Additionally, coherent transition radiation (CTR) and diffraction radiation (DR) based techniques will be evaluated. These beam characterizations will support self-amplified spontaneous emission (SASE) scaling experiments.