TOMOGRAPHIC METHOD FOR MEASURING DISTRIBUTION-FUNCTIONS IN TRAJECTORYAND PHASE-SPACE IN CHARGED-PARTICLE BEAMS MONITORS

A facility to monitor intense beams of charged particles in vacuum aut omatically has been designed. The coordinate resolution and measuremen t accuracy is considerably improved by using a sophisticated correctio n method for the spread function of the beam probe, by statistical dat a processing, and by automatically determining the beam axis. Profiles of an electron beam with a half-width of approximate to 0.5 mm and a power density of 10(9) W/m(2) have been measured for several sequentia l cross sections. This technique allows us to derive distribution func tions in charged particle beams along two-, three-, and four-dimension al transverse trajectories, and, if the beam is monoenergetic, the dis tribution function can be derived in phase space from a set of one-dim ensional projections without any a priori knowledge of the shapes of t he isosurfaces of the distribution functions. Diagrams of the current density in an intense (2 . 10(8) W/m(2)) narrow (similar to 0.5 mm) el ectron beam in two- and three-dimensional transverse trajectory spaces in several sequential cross sections have been derived from a set of one-dimensional projections. Both divergent and convergent components have been detected in a nonlaminar beam.