On the performance of scintillation screens and radiographic films at the acquisition of images using thermal neutrons and X-rays

The performance of image acquiring systems operating by transmission of thermal neutrons and X-rays have been evaluated and compared. In both systems radiographic films have been used to catch the transmitted images, while that one using a reactor as thermal neutron source utilized also a scintillation screen for the same purpose. Images of several objects have been taken with those systems allowing a qualitative comparison of their resolution, while the quantitative performance of the thermal neutron systems have been assessed through determination of the modulation transfer function-MTF. The obtained results show the complementary character of thermal neutron and X-rays as tools for non-destructive assays. Furthermore, the results obtained with a conventional photo-camera catching the image produced by a scintillation screen shows a very slight difference in the quality with regard to that acquired with a radiographic film, which by the way is more expensive, demands a longer exposition time and cannot obviously deal with moving objects as the scintillation screen does, when used together with a video-camera, as done in this work as well