Amorphous silicon imaging system for improved x-ray image capture in nondestructive evaluation

Film has been the primary x-ray acquisition medium for many years and is still widely used for NDE radiography. In recent years new technologies have been developed for x-ray image capture that offer the promise of improvement over film by taking advantage of digital systems. The availability of a direct digital detector, high speed computers, digital networking, and large capacity storage brings new capabilities to the radiographer in filmless radiography. These capabilities provide images that can be stored in mass digital storage systems offering longer storage life and faster retrieval, image processing software can be used to enhance images and provide computer assisted interpretation, and high quality digital images that can be transmitted from remote sites to interpretation centers. Amorphous silicon image sensors, developed by dpiX, A Xerox New Enterprise Company, offer an improved method of acquiring digital x-ray images. Amorphous silicon image sensor technology provides the opportunity to have large format size similar to x-ray film, high resolution, and a compact package for ease of use in NDE applications. This technology can also be used to replace x-ray examination of objects on a conveyor belt. This paper presents a description of amorphous silicon image sensor technology and a system developed to demonstrate the capabilities of this technology. This system called the FlashScan 20 has an 8 X 10 inch x-ray image acquisition area with a pixel matrix of 1536 X 1920 127 micron pixels.