FLAW DETECTION, SIZING AND LOCATION BY DIFFERENTIAL GAMMA SCATTERING SPECTRUM TECHNIQUE

THE PROGRAM PROPOSED HEREIN INVOLVES ANALYTICAL AND EXPERIMENTAL RESEARCH TO CAREFULLY EVALUATE AND FURTHER DEVELOP THE DIFFERENTIAL GAMMA SCATTERING TECHNIQUE FOR ACCURATE NON-INVASIVE DETERMINATION OF VOIDS, CRACKS, FLAWS IN MATERIALS AND THE DEFECTS SIZING AND LOCATION CAPABILITIES OF THIS METHOD. THIS NEW DEVICE, WHICH WE HAVE TERMED "DIFFERENTIAL GAMMA SCATTERING SPECTRUM PROBE (DGSSP)," IS BASED ON THE DETECTION AND HIGH-RESOLUTION ENERGY DISCRIMINATION OF THE SCATTERED PHOTON FIELD EMERGING FROM AN OBJECT WHICH IS ILLUMINATED BY A BEAM FROM A SUITABLY COLLIMATED MONOENERGETIC GAMMA-RAY SOURCE. SUBTRACTION OF THE SCATTERED SPECTRUM FROM A DEFECTIVE SAMPLE AND THE SCATTERED SPECTRUM FROM A SIMILAR BUT INTACT SAMPLE RESULTS IN A DESCRETE PEAK-SHAPE SPECTRUM WHICH IS TERMED "DIFFERENTIAL GAMMA SCATTERING SPECTRUM (DGSS)". THE LOCATION OF FLAW (OR FLAWS) IS INDICATED BY THE POSITION OF THE PEAK (OR PEAKS) IN THE DGSS AND THE SIZE OF THE FLAW IS PROPORTIONAL TO THE AREA UNDER THE PEAK. IT IS THIS UNIQUE CHARACTERISTIC FOR A DGSS PROBE WHICH ACCOUNTS FOR THE NOVELTY OF THIS CONCEPT AND LEADS TO NOTED SIGNIFICANT ADVANTAGES OVER PREVIOUS ULTRASONIC, GAMMA OR X-RAY TRANSMISSION OR SCATTERING METHODS.