Developing a compton telescope prototype using single-crystal diamond detectors

Abstract

Observing cosmic sources in the medium-energy gamma-ray regime (~0.4 - 10 MeV) requires highly efficient instruments with high angular resolution and robust background rejection. Artificial single-crystal diamond detectors (SCDDs) are comparable to traditional silicon solid-state detectors (SSDs) in terms of energy range, energy resolution, and threshold levels. However, they exceed SSD performance with faster rise times, improved radiation hardness, and insensitivity to light and temperature. CeBr₃ scintillator is a high density, high Z material with fast rise times and good energy resolution ( 4% FWHM at 662 keV) make it a promising gammaray calorimeter. Here, we outline ongoing work by Southwest Research Institute (SwRI) to develop readout and data acquisition electronics to characterize SCDDs. Additional work is ongoing at Los Alamos National Laboratory to characterize CeBr3 scintillator detectors that are read out with silicon photomultipliers (SiPMs). Currently, an off the shelf ASIC system from PETsys Electronics (TOFPET2 ASIC),¹ developed for time-of-flight (ToF) positron emission tomography (PET), is used to record the CeBr₃ data. After characterization of the CeBr₃ and SCDDs, we plan to bring them together to form a prototype Compton telescope. Performance of the prototype will benchmark simulations of a functional Compton Telescope to predict the sensitivity of an optimized instrument for a satellite platform.