Design and performance of a compact imaging system for the APS linac bunch compressor

We present the design and performance of a high-resolution, high charge sensitivity imaging camera system for the APS linac beam profile measurement. The electron beam distribution is converted to a light intensity distribution using standard YAG or optical transition radiation (OTR) screens. Two CCD cameras share the light through a beam splitter, each with its own imaging optics. One camera is normally set to a low magnification to give a full view of the converter screen (20 mm × 15 mm), and the other is set to a high magnification for measuring small beam. The overall dimension of the camera system is 400 mm × 165 mm × 110 mm. The focus and irises are driven by stepper motors and are remotely controlled. The fixed magnification and remotely controlled focus enable high reproducibility during beam-based setup of the optics. On a bench test, the camera gave a better than 10-μm resolution and better than 1% reproducibility of the magnification