A New Laser Scanning System for Computed Radiography

Abstract

X-ray inspection is widely used in aviation, aerospace, weapons, nuclear energy, automobile and other fields for non-destructive testing and non-destructive evaluation. It plays an important role in engineering quality supervision and quality control, and it has become a basic technology in industry and high-tech industry. With the strength of visuality, high sensitivity and high resolution, X-ray screen-film radiography is widely used in industrial non-destructive testing, medical imaging and other fields. However, it has some disadvantages of low efficiency and films being not reusable. Due to this, there have been some new methods of digital imaging for radiographic inspection such as the analog imaging based on image intensifier, the large array detector imaging based on Thin Film Transistor (TFT), and the computed radiography (CR) imaging based on the photo-stimulated luminescence (PSL). As the imaging plate of a CR system has some advantages of large dynamic range, erasibleness, high sensitivity, high spatial resolution, flexibility, etc. It has become a key research field (Brandt, 1993; Cowen et al., 2007; Dragusin et al., 2006; Satoshi et al., 1999; Schaetzing et al., 2002). Some commercial CR systems, especially for medical imaging, have also emerged. With higher production standards for long-distance oil and gas pipeline systems, X-ray inspection of pipe ends and patching has become a key means for inspecting harmful defects in major domestic and international long-distance pipelines in order to guarantee their quality. Having shared the merits of industrial film radiography of large ray dosage absorption, flexibility, and higher spatial resolution, CR systems also enjoy new edges such as digital imaging, large image dynamic range and re-usable image plate, and it will play a key role in industry applications such as pipe quality testing and controlling. However, the high cost of CR systems has hindered their development in the field of industrial testing which is not so profitable. Therefore, to sharpen the competitive edge of CR systems in industrial testing, it is necessary not only to improve the inspection efficiency and image quality of the image plate, but also to significantly reduce the costs of CR systems. Readout technology and equipment are the key technology and core part of CR systems and it also play a key role in the cost of the CR system. Theretofore, how to improve the resolution and scanning speed of readers and how to efficiently collect weak fluorescent signals in a simpler way and lower cost have been a focus for studies in this field.