Search

Multi-Nucleon Transfer (MNT) reactions have been used for decades as a reaction mechanism, in order to populate excited states in nuclei far from stability and to perform nuclear structure studies. Nevertheless, the development of set-ups involving high acceptance tracking magnetic spectrometers (mainly existing in Europe), coupled with the Advanced GAmma Tracking Array (AGATA) opens new possibilities, especially if they are used in conjunction with high-intensity stable beams or ISOL RIBs. In this article, we will discuss the capabilities of such set-ups aiming at different goals, including complete information in high-resolution spectroscopy as well as lifetime measurements. [ABSTRACT FROM AUTHOR]

In recent decades, γ -ray spectroscopy has undergone a major technological leap forward, namely the technique of γ -ray tracking, and has attained a sensitivity that is two orders of magnitude larger than that provided by the former generation of Compton-shielded arrays. Indeed the gain is comparable with the achievements since the dawn of γ -ray spectroscopy. Such sensitivity can be further heightened by coupling γ -ray spectrometers to other detectors that record complementary reaction products such as light-charged particles for transfer reactions and scattered ions for Coulomb excitation measurements. Nucleon transfer reactions offer an excellent mean to probe the energies of shell model single-particle orbitals and to study migration in energy of these orbitals as we venture away from stability. Such measurements can also estimate the cross sections of processes relevant to stellar evolution and nucleosynthesis. The measurement of γ rays in coincidence with particles provides also information on the decay channel for unbound systems, which constitutes a useful input for astrophysics and nuclear structure near the drip-lines. Coulomb-excitation studies make it possible to infer collective structure in nuclei and to extract deformation properties of, in particular, open-shell systems. Here, selected examples will be presented, highlighting the power of these types of experiments when γ -ray observation is included. The development of the experimental methods is reviewed, showing the results achieved before the advent of γ -ray tracking. Examples of more recent experiments that have successfully exploited γ -ray tracking with AGATA are then presented as showcases for the outstanding performance of the composite detection systems. The outlook for experiments using newly developed devices such as GRIT and other detectors such as SPIDER is described. [ABSTRACT FROM AUTHOR]

Presently, γ -ray tracking in germanium segmented detectors is realised by applying two advanced, complex algorithms. While they have already triggered an intensive R &D, they are still subject to further improvements. Running the common code for these core algorithms in both the online/real-time and offline data pipelines posed significant challenges. These were addressed in current production software, but also require continued attention in view of significant on-going paradigm shifts in both hardware and software technology. This review paper gives an overview of the various software components produced so far by the AGATA collaboration. It provides hints of what is foreseen for the next phases of the project up to its full configuration namely with 180 capsules in the array. [ABSTRACT FROM AUTHOR]

7Example of different TKEL conditions for 92 Mo using the shortest target-to-degrader distance. a Doppler-corrected spectrum without a TKEL condition. b Condition on the low part of the TKEL. c More restrictive condition on the low part of the TKEL. d Condition on the high part of the TKEL. 10Simulated Doppler corrected -ray spectra using the velocity from PRISMA (after the degrader) for 50 Ca showing the DSAM and RDDS techniques. The original article can be found online at https://doi.org/10.1140/epja/s10050-023-01027-2. [Extracted from the article]

A recent experiment on 12C + 24Mg sub-barrier fusion was performed. Standard coupled-channels calculations clearly over-estimated the low energy cross sections and there was indication of a maximum of the astrophysical S factor vs energy. In the present work further measurements have been performed on the same system, and we extended the excitation function to lower energies down to σ ≃ 4 ÎĽ b, confirming the existence of the hindrance phenomenon. Additional energy points near the barrier were added as well. In agreement with the result of previous experiment, the hindrance energy threshold is observed to correspond to a remarkably large cross section. The present new data allow to better define the S -factor maximum, that is well fitted using two parametrizations of either the hindrance or the adiabatic model. We also performed coupled-channels calculations using a Woodsâ€"Saxon potential. Far below the barrier we observe that the coupling strengths decrease and tend to vanish, indeed one-dimensional tunnelling calculations well reproduce the excitation function. Further precise cross section measurements at slightly lower energies are needed to discriminate between the adiabatic and hindrance models. This would give a reliable guidance for the extrapolation to the systems of astrophysical interest, like 12C + 12C and 16O + 16O. [ABSTRACT FROM AUTHOR]