A HIGH-SPEED GATEABLE IMAGE PIPELINE

We present the performance of a high-speed gateable vacuum image pipel ine, which permits individual images to be delayed and selected from c ontinuous non-repetitive image stream. This device is composed of a va cuum tube equipped with a photocathode at one end, a phosphor screen a t the other end, and a system of metal grids in between. Photoelectron s produced by the images focused on the photocathode, are guided by a uniform, magnetic field, parallel to the tube axis. By changing the gr id potentials, the drift time of the photoelectrons inside the tube ca n be varied from 0.35 to 1.5 mu s. An image can then be selected by an external trigger with a time resolution in the range of 4-30 ns, depe nding on the delay time. The selected photoelectrons are finally accel erated onto the phosphor screen, set at IO kV, where they reproduce th e desired image. With a magnetic field of 0.1 T, a spatial resolution of 33 lp/mm was obtained. The high spatial and time resolution make th is device an interesting tool for high-energy physics and astrophysics experiments, and for high-speed photography.