CROSS-SECTIONAL OBSERVATION OF LUMINOUS BROADENING IN YAG SCINTILLATOR

Luminous broadening in a YAG scintillator for a fine electron beam inj ection has been directly observed from the side of the scintillator by a TV camera system. The incident energy is between 0.5 and 2.0 MeV. T wo-dimensional intensity distribution has been obtained. From this dis tribution, the line spread function (LSF), the edge spread function (E SF) and the point spread function (PSF) can be calculated. The ESF est imated by this method agrees well with the ESF measured by a knife edg e method when a small background level by the back scattered electrons is compensated. Full width at half maximum of the PSF for a 200 mu m thick scintillator is 31 mu m at 2 MeV.