Beam characterization with video imaging systems at the ANL 50 MeV H- beamline

Video imaging systems consisting of scintillators, charge-coupled device (CCD) cameras, and in-beam CCD detectors are being used to characterize beams at the Argonne National Laboratory (ANL) 50 MeV H^- beamline. The characterization technique consists of placing pinholes, slits, or wires in the beam and viewing the resulting images or shadows on a downstream scintillator or CCD. The images are digitally recorded using a frame grabber and stored in computer memory where they are analyzed to determine Twiss parameters and local beam divergence. Since many of the measurements involve low-intensity beams and require good position resolution, studies have been performed on scintillators to obtain sensitivity and resolution data. Various scintillators, including Rarex, CsI, and CaF₂, have been evaluated. An in-beam CCD imager has also been tested