Y2O2S:Eu phosphor screens evaluation.

The x-ray luminescence of Y2O2S:Eu phosphor screens is studied both in transmission and in reflection mode observation. Detailed experimental data concerning the dependence of the absolute efficiency on the tube voltage and the screen's thickness are presented and comparisons to another rare earth phosphor material (Y2O2S:Tb) are given. With the help of theoretical calculations based on the Hamaker-Ludwig model all the experimental data are explained and the intrinsic efficiency and scattering coefficients of the phosphor are estimated.