G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
G21K1/02—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators
G21K1/025—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation