Energy and coincidence-time resolution of the LaBr3:Ce-MPPC™ detectors under magnetic fields

Abstract

Time-differential perturbed angular correlation (TDPAC) spectroscopy is a nuclear solid-state technique that requires high energy and coincidence-time resolutions from scintillation crystals and photodetectors. Traditionally, photomultiplier tubes (PMTs) have been coupled to LaBr3:Ce crystals; however, they have been replaced by Multi Pixel Photon Counters (MPPCs) for TDPAC experiments conducted under external magnetic fields. In this report, we show that, for TDPAC spectroscopy, the performance of the LaBr3:Ce-MPPC detector remains stable under magnetic fields up to 8.5 T (in 1 T steps), as evidenced by the unchanged energy and coincidence-time resolutions of the 511 keV peaks from positron–electron (e+-e-) annihilation in a sealed 22Na calibration source.