Multidisciplinary evaluation of X-ray optical fiber sensors

Abstract We report the complex evaluation of an extrinsic optical fiber sensor for X-ray detection, consisting of different phosphor materials (ZnS:Ag, Gd 2 O 2 S:Pr, Gd 2 O 2 S:Eu, Gd 2 O 2 S:Tb) optically coupled to the end of a plastic optical fiber. X-ray fluorescence and radioluminescence measurements were used for the evaluation of sensors responsivity. The sensitivity and linearity of sensors response as a function of the X-ray source voltage and current were assessed. The dependence of the sensor responsivity on the irradiation dose rate was measured. X-ray radiography and tomography were employed to investigate the homogeneity of the active material distribution inside the detecting tip. The most sensitive sensor proved to be that based on Gd 2 O 2 S:Tb, fixed with the EpoFix glue and manufactured using a plastic cylinder to shape the sensor tip.