Abstract

The absolute luminescence efficiency (AE) of a calcium fluoride (CaF₂:Eu) single crystal doped with europium was studied using X-ray energies met in general radiography. A CaF₂:Eu single crystal with dimensions of 10 × 10 × 10 mm³ was irradiated by X-rays. The emission light photon intensity of the CaF₂:Eu sample was evaluated by measuring AE within the X-ray range from 50 to 130 kV. The results of this work were compared with data obtained under similar conditions for the commercially employed medical imaging modalities, Bi₄Ge₃O₁₂ and Lu₂SiO₅:Ce single crystals. The compatibility of the light emitted by the CaF₂:Eu crystal, with the sensitivity of optical sensors, was also examined. The AE of the 10 × 10 × 10 mm³ CaF₂:Eu crystal peaked in the range from 70 to 90 kV (22.22 efficiency units; E.U). The light emitted from CaF₂:Eu is compatible with photocathodes, charge coupled devices (CCD), and silicon photomultipliers, which are used as radiation sensors in medical imaging systems. Considering the AE results in the examined energies, as well as the spectral compatibility with various photodetectors, a CaF₂:Eu single crystal could be considered for radiographic applications, including the detection of charged particles and soft gamma rays. View Full-Text