State-of-the-Art Gamma-Ray Spectrometers for In-Beam Measurements

Abstract

High-resolution γ-ray spectroscopy is one of the most powerful and sensitive tools to investigate nuclear structure. Significant progress in this field has been achieved through the use of arrays of Compton-suppressed high-purity germanium detectors; however, it is apparent that such devices are not suited to the expected experimental conditions at the planned and under construction radioactive ion beam facilities. Devices with higher efficiency and sensitivity have been developed during the past two decades relying on the possibility to determine the position and the energy deposition of the individual interaction points of a photon within a germanium crystal and on the capability to reconstruct the photon scattering sequence through powerful data analysis algorithms. In these notes a brief introduction to the principles of γ-ray tracking arrays will be given. After a historical overview of the main spectrometers that contributed to the present understanding of the nuclear structure, the principles of advanced γ-ray tracking will be described. A basic technical description of arrays based on this technique will be reported together with some selected results.