Wide range automatic energy calibration of LaBr3:Ce detectors by the self-activity lines

A real-time automatic energy calibration (RAEC) algorithm of a LaBr₃:Ce scintillation detector array has been developed. The energy markers for this calibration are the self-activity lines inherently existing inside the LaBr₃ crystal. Five energy markers were used in this technique. Two lines are from the radioactive isotope of lanthanum, ¹³⁸La, at 789 and 1436 keV while the other three are from the ²²⁷Ac which is thought to be the source of the self-activity of LaBr₃ detectors near 2 MeV energy range. The energy calibration extracted from RAEC algorithm is evaluated by a comparison with the energy calibration that was established using ⁵⁶Co radioactive checking source. The two energy calibrations showed a good agreement, indicating a high potential to use the self-energy calibration technique for LaBr₃:Ce detectors.