The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation γ-ray spectrometer. AGATA is based on the technique of γ-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a γ ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of γ-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer

The gamma decay from Coulomb excitation of 68Ni at 600 MeV/nucleon on a Au target was measured using the RISING setup at the fragment separator of GSI. The 68Ni beam was produced by a fragmentation reaction of 86Kr at 900 MeV/nucleon on a 9Be target and selected by the fragment separator. The gamma rays produced at the Au target were measured with HPGe detectors at forward angles and with BaF2 scintillators at backward angles. The measured spectra show a peak centered at approximately 11 MeV, whose intensity can be explained in terms of an enhanced strength of the dipole response function (pygmy resonance). Such pygmy structure has been predicted in this unstable neutron-rich nucleus by theory.

The total photoabsorption cross section for 7Li, C, Al, Cu, Sn, Pb has been measured in the energy range 300–1200 MeV at Frascati with the jet-target tagged photon beam. A 4π NaI crystal detector and a lead-glass shower counter were used, respectively, to measure hadronic events and to reject the electromagnetic background. Data above 600 MeV clearly indicate a broadening of higher nucleon resonance peaks in nuclei and a reduction of the absolute value of the cross section per nucleon with respect to the free-nucleon case. This large broadening suggests a strong influence of the nuclear medium in the resonance propagation and interaction, while the systematic reduction of the measured cross sections might be due to a depletion of the resonance excitation strength and to the onset of the shadowing effect around 1 GeV. Moreover, our systematic study indicates that also the Δ-resonance excitation parameters are not the same for all nuclei, being its mass and width increasing with the nuclear density

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