A high-resolution, high-speed CT/radiography system for NDT of adhesive bonded composites

摘要

Adhesive bonded composites used in naval, aerospace, and automotive technologies require routine nondestructive testing (NDT) to detect flaws and other integrity-reducing anomalies such as porosity, kissing disbonds, and delaminations. We have developed an x-ray radiography/CT system with fast scanning times based on high resolution, high efficiency scintillators coupled to a 1024 x 1024 pixel CCD via a fiberoptic taper. Typical CT systems for NDT use a fan beam x-ray source and a linear array of detectors, with scan times on the order of 10 hours depending on the desired resolution. The prototype CCD-based volumetric imaging system described here is capable of reducing this scan time to <1 hour while significantly improving resolution. Additionally, the system is capable of both CT and standard radiographic imaging. We have integrated two different scintillators in the prototype system. One is a structured CsI(Tl) screen, and the other is a new, pixelated, transparent optical ceramic (TOC) scintillator. This unique TOC has a density of 9.5 g/cm~3 and a peak emission of 610 nm, particularly suitable for Si readouts. We present here the system design and preliminary results of radiographic imaging and volumetric CT reconstruction.