We obtained a sequenti.il series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns eh tron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 0°, 61 = , and 117°. The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camem where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the

more »

... ntropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam put -e.