Evaluation of the co-doped LSO:Ce,Ca scintillator crystal in the X-ray energy range from 50 to 140kVp for medical imaging applications

Cerium doped Lutetium oxyorthosilicate (LSO) is a well-known scintillator that is widely used for gamma-ray detection in counting mode applications. LSO is typically doped with 0.05 - 0.5% Ce while controlling other impurities at low levels. An investigation of the manner in which various co-dopands may influence the scintillation properties, has begun recently. It was found that some co - dopants, particularly Ca⁺², have a desirable impact on scintillation properties, leading to improvements in both light yield and decay time that are related to co - dopant concentration. The aim of the present work is to evaluate the performance of four (4) samples with dimensions 5 × 5 × 5 mm³ of LSO:Ce,Ca with different Ca⁺² co- dopand concentrations varying from 0.1 to 0.4 %, in the X-ray energy range between 50 and 140 kVp, for possible medical imaging applications. Scintillation measurements were performed using an experimental setup based on a photomultiplier coupled to a light integration sphere. The radioluminescence emission spectra of LSO:Ce,Ca scintillators were measured and the spectral compatibilities to various optical photon detectors incorporated in medical imaging systems were extracted. Results were compared with data on LSO:Ce single crystal scintillator in terms of absolute luminescence efficiency and spectral matching factor.