Local Level Processing
Ancillary detectors
Triple cluster in-beam test
Agata at GANIL - SPIRAL2

At a time when new facilities for radioactive-ion beams and high-intensity stable beams are emerging in Europe, the nuclear structure physics community is proposing a major breakthrough in instrumentation for gamma-ray spectroscopy. The first real 4 Pi gamma-ray spectrometer solely built from Germanium detectors is based on the novel technique of gamma-ray tracking. The "Advanced GAmma Tracking Array" (AGATA) will be an instrument of major importance for nuclear structure studies at the very limits of nuclear stability, capable of measuring gamma radiation in a large energy range (from a few tenths of keV up to 10 MeV and more), with the largest possible efficiency and with a very good spectral response.

The exotic nuclei of interest are often rarely produced, but can be accompanied by much more abundant, less exotic species. The radiation can be emitted by fast moving sources and in a hostile environment of high background radioactivity (Bremsstrahlung, neutrons and charged particles, etc.). This requires the simultaneous optimisation of several and sometimes conflicting properties:

These features can only be simultaneously achieved by a novel type of Ge detectors, called gamma-ray tracking detectors, which significantly improve the efficiency, resolving power and spatial resolution of 4 Pi arrays for high-precision gamma-ray spectroscopy. The idea of Gamma-ray tracking has only become possible now due to major improvements in Ge detector technology and digital pulse processing electronics. Gamma-ray tracking detectors consist of highly segmented Ge crystals and a front-end electronics, based on digital signal processing techniques, which allows to extract, in real time, energy, timing and spatial information on the gamma-ray interactions in the Ge detector by pulse-shape analysis of its signals. Utilising the information on the position of every interaction point of any detected gamma-ray and the energy released at this point, the tracks of the gamma rays in a Ge shell can be reconstructed in three dimension by numerical (tracking) algorithms, mainly because of the angle-energy relation provided by the Compton scattering formula.

The AGATA Project

Physics with AGATA at EURISOL

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