Cherenkov Light as a Current Density Diagnostic for Large Area, Repetitively Pulsed Electron Beams

Cherenkov light intensity is an ideal electron beam current density diagnostic, giving information about the beam´s spatial distribution as a function of time during a pulse. It is free of the fluorescence and saturation often observed in scintillators provided a suitable radiator is chosen. Plate glass has been used for single pulse applications. For repetitively pulsed beams a flowing liquid radiator is used to reduce problems arising from heating and decomposition of the material. Light output is sufficient to study 1 A/cm2, 250 kV beams with ASA 3000 speed film. Streak photography also appears possible.