HIGH SENSITIVITY, ONE-SIDED X-RAY INSPECTION SYSTEM

A SENSITIVE NONDESTRUCTIVE METHOD TO USE SCATTERED X-RAYS TO DETECT AND SIZE DEFECTS FROM ONE SIDE OF THE OBJECT IS DESCRIBED. RADIATION SCATTERED FROM A COLLIMATED X-RAY BEAM CAN BE DETECTED TO REVEAL INTERNAL INHOMOGENEITIES. A NOVEL DETECTOR COLLIMATION SLOT PROVIDES INCREASED DETECTION SENSITIVITY AND, BY ADJUSTMENT OF THE INSPECTION GEOMETRY, ALSO PROVIDES MAGNIFICATION OF THE SCATTERED BEAM. THIS CAN BE USED TO EHANCE SENSITIVITY AND TO SIZE DEFECTS THAT MAY BE EXTREMELY SMALL. THE TECHNIQUE ALSO PROVIDES DEFECT DEPTH INFORMATION. THE OBJECTIVES OF THE PROGRAM ARE TO DETERMINE THE DEFECT DETECTION SENSITIVITY AND SIZING CAPABILITY FOR DAMAGE IN SIMULATED ROCKET PRESSURE VESSELS MADE FROM KEVLAR-EPOXY AND GRAPHITE-EPOXY. PRELIMINARY INDICATIONS ARE THAT THE METHOD WILL DETECT CRACKS, VOIDS AND EVEN THE SLIGHT GAP OF TWO SURFACES IN MECHANICAL CONTACT, IN BONDED STRUCTURES A PHENOMENON KNOWN AS A KISSING BOND. THE GEOMETRIES CHOSEN FOR STUDY WILL BE CYLINDERS WITH INTERNAL LAMINATED STRUCTURE MADE FROM THE MATERIALS OF INTEREST. THIS GEOMETRY WILL SIMULATE MANY WEAPONS SYSTEMS AND MILITARY HARDWARESUCH AS MISSILES, ROCKETS AND ORDNANCE DEVICES. IT SHOULD BE EMPHASIZED THAT THIS ONE-SIDED X-RAY TECHNIQUE WILL PROVIDE AN INSPECTION METHOD FOR ROCKET MOTOR PRESSURE VESSELS AND OTHER MISSILE HARDWARE FOR BOTH FACTORY AND FIELD USE. IN THE FIELD, IT OFFERS UNIQUE INSPECTION CAPABILITY.