Efficiency calibration and coincidence summing correction for a large volume (946 cm³) LaBr₃(Ce) detector: GEANT4 simulations and experimental measurements

The paper describes the studies on efficiency calibration and coincidence summing correction for a 3.5″×6″ cylindrical LaBr₃(Ce)detector. GEANT4 simulations were made with point sources, namely, ⁶⁰Co, ⁹⁴Nb, ²⁴Na, ⁴⁶Sc and ²²Na. The simulated efficiencies, extracted using ⁶⁰Co, ⁹⁴Nb, ²⁴Na and ⁴⁶Sc that emit coincident gamma rays with same decay intensities, were corrected for coincidence summing by applying the method proposed by Vidmar et al. (2003). The method was applied, for the first time, for correcting the simulated efficiencies extracted using ²²Na that emits coincident gamma rays with different decay intensities. The measured results obtained using ⁶⁰Co and ²²Na were found to be in good agreement with simulated results. - Highlights: • Coincidence summing correction in a large LaBr₃(Ce) detector. • Estimation of corrected absolute efficiencies by employing the method suggested by • Validation of the method for a positron emitter. • The measured results obtained using ⁶⁰Co and ²²Na were found to be in good agreement with simulated results.