Investigation of imaging and spectroscopy performances of a 1″×1″ LaBr3:Ce scintillator readout by Silicon Drift Detectors for nuclear physics measurements

In this work we propose a gamma detector based on Silicon Drift Detectors to readout a 1"×1" LaBr₃:Ce scintillator for gamma-ray spectroscopy and imaging application. Position sensitivity could be useful in nuclear physics research to limit the worsening effect of Doppler broadening in gamma-ray spectroscopy at relativistic velocities. The main difficulty in determining the position of the gamma-ray interaction in the crystal is associated to the thickness/diameter ratio of the crystal (in our case 1:1) and the use of reflectors on all lateral and top sides of the crystal. This last choice enhances energy resolution, but makes imaging capability more challenging because light is spread over all photodetectors. Preliminary results show that the camera is able to detect shifts in the measured signals, when a ¹³⁷Cs (662 keV) source is moved with steps of 5 mm. A modified version of the centroid method is finally implemented to evaluate the imaging capability of the system.