CCD-BASED HIGH-RESOLUTION DIGITAL RADIOGRAPHY SYSTEM FOR NON DESTRUCTIVE EVALUATION

Film radiography has long served the aerospace industry as a principal method for hardware flaw detection. Although excellent in performance , this method is extremely time consuming, labor intensive, costly, an d is unsuitable for real time inspections. Modern digital radiographic systems overcome some of these difficulties but are also limited in t erms of speed of operation due to persistence of the sensor and a prob lematic tradeoff between the X-ray detection efficiency and spatial re solution. We are developing an innovative X-ray imaging detector consi sting of a novel microstructured CsI scintillator coupled to a fiberop tic taper-based CCD. Thin-film deposition techniques, previously devel oped to produce thin, structured CsI screens have been extended to fab ricate CsI screens, up to 450 mg/cm(2) (1,000 mu m) in thickness. Thes e sensors are suitable to provide high detection efficiency with high image quality for NDE applications. A prototype high energy imaging sy stem was constructed by integrating these screens into a fiberoptic-ba sed CCD camera. The performance was compared to that of the same syste m using a standard polycrystalline phosphor for NDE imaging applicatio ns. The experimental evaluations were carried out at Scientific Measur ement Systems, Inc., Austin, TX.