In order to apply digital radiography to the spacecraft, an improvement of the resolution for the flat panel detector has been studied. A higher resolution has been obtained by the following methods: First, the resolution of the scintillator has been gained by improving the granular nature of crystal and cross talk. Secondly, the silicon wafer has been improved by suppressing the collection of the electric charge generated in portions other than the photodiode. The resolution of the improved flat panel detector using the X-ray test chart was found to be 8.7 Lp/mm as contrasted to 6.3 Lp/mm of the detector before improvement. The image quality level has been studied under different radiographic parameters (tube-voltage, distance between the focal spot and flat panel detector, accumulation time, etc.), and appropriate conditions have been examined for developing this detector. Examples of radiographic images are shown in comparison with the results of X-ray film.

No abstract