It is built from large crystals of hyper-pure germanium and uses the recently developed concept of gamma-ray energy tracking.
GRETINA is a gamma-ray detector array capable of reconstructing the energy and spatial positions of gamma-ray interactions within the germanium crystals. It is used to study the structure and stability of nuclei under various conditions. The new capabilities provided by gamma-ray tracking give large gains in sensitivity for a large number of experiments, particularly those aimed at nuclei far from beta stability.
GRETINA was located at ATLAS for an experimental campaign of approximately two years from 2013 – 2015. A large number of experiments utilized beams from CARIBU to perform Coulomb excitation studies of neutron-rich isotopes by coupling the CHICO II particle detector with GRETINA.
In upcoming studies, GRETINA will be stationed in front of the Fragment Mass Analyzer (FMA) to allow studies of nuclei at or near the proton drip line and along the rp process. Up to 44 crystals covering about 1/3 of the solid angle will be mounted in the array.