Relative Yields of Radioluminescence and Thermoluminescence in Several TL Phosphors

During the interaction of ionising radiation with matter a part of the absorbed energy is transferred to prompt luminescence or fluorescence, another fraction is stored in the form of trapped charge carriers mostly at lattice defect sites, while the rest is dissipated through non-radiative processes. Although the efficiency of the energy storage is one of the most important questions in the investigation of the TL materials, its absolute measurement is difficult, and needs sophisticated calibration procedures. The present paper reports on relative efficiencies of charge trapping vs luminescence production in the most widely used TL dosemeter materials, based on parallel measurements of radioluminescence and thermoluminescence with the same light detection system. In this way it was possible to measure relative yields without geometrical, optical transmittance and detection efficiency corrections. The measured relative thermoluminescence vs radioluminescence yields for several widely used phosphors (LiF, Al2O3, CaSO4 and CaF2) are presented.