“Scintillator-photodiode” detectors for scanning introscopy with high-spatial resolution

The improvement of spatial resolution, together with reducing the dose load upon the tested object and making the scanning time shorter, is an essential aim in designing new radiographic systems. In this paper, we consider a possibility to use “scintillator-photodiode” detectors in radiographic systems in order to obtain resolution better than 1 line pair per mm (detector array pitch less than 1 mm). A possibility is considered to use various types of scintillators (CsI(Tl), CdWO4, ZnSe(Te)), various kinds of scintillation elements (separate scintillation elements, scintillation monoplates, plates made of a small-crystalline scintillator and a binding substance) with differently treated surfaces, different binders, reflective coatings, photoconverters (photodiode or photodiode+amplifier+commutator in one housing). It has been shown that ZnSe(Te) scintillators are preferable for detectors of X-ray and low-energy gamma-radiation (20–100 keV) with array pitch as small as 0.2 mm. CsI(Tl) should be used for 70–200 keV energies (0.4 mm pitch), CdWO4 crystals—for 0.3–10 MeV energies (pitch 0.4 mm).