Abstract :
An image convertor has been used as a shutter mechanism for exposure durations of less than 1 microsec. The electron emission from the photo-cathode is controlled by suitable electrode potentials and the fluorescent image formed during the exposure interval is recorded photographically. The characteristics of two types of image convertor are discussed, distortions which are peculiar to short exposure conditions are observed and an explanatory mechanism is suggested. The use of magnetic image deflection, whereby a line image may be given a deflection which varies with time, is also described, and streak records showing the variations in the object (along one dimension) as a function of time are discussed.