Transfer Reaction Studies with Spectrometers

Abstract

The revival of transfer reaction studies benefited from the construction of the new generation large solid angle spectrometers, coupled to large γ arrays. The recent results of γ-particle coincident measurements in 40 Ca+ 96 Zr and 40 Ar+ 208 Pb reactions demonstrate a strong interplay between single-particle and collective degrees of freedom that is pertinent to the reaction dynamics. The development of collectivity has been followed in odd Ar isotopes populated in the 40 Ar+ 208 Pb reaction through the excitation of the 11/2 − states, understood as the coupling of single particle degrees of freedom to nuclear vibration quanta. Pair transfer modes is another important degree of freedom which is presently being studied with Prisma in inverse kinematics at energies far below the Coulomb barrier. First results from the 96 Zr+ 40 Ca reaction elucidate the role played by nucleon-nucleon correlation.

The Legnaro National Laboratories and the SPES facility: nuclear structure and reactions today and tomorrow

“…As the energy resolution is currently limited to a few hundred keV, the spectrometer has been coupled to large γ-ray detector arrays (CLARA, AGATA) in order to separate the excited states of the final fragments. The total kinetic energy spectrum for 48 Ca gated on γ-rays and the corresponding γ-array spectrum, obtained after Doppler correction based on knowledge of the velocity vector measured in PRISMA, are shown in figure 13 [47,48]. As already noted, a very important use of such γ-particle coincidence technique concerns studies of moderately neutron-rich nuclei whose structures are poorly known.…”

“…Such limitations have been overcome by the development of large-acceptance magnetic spectrometers with retracing capabilities, such as PRISMA at LNL, which have allowed us to reach very large angular coverage preserving the charge, mass and energy resolutions by means of the reconstruction of the ion trajectories. As an example of the performance of large solid angle spectrometers, figure 12 shows the mass distribution of the isotopes populated in the 48 Ca + 64 Ni reaction measured with PRISMA [47,48]. As the energy resolution is currently limited to a few hundred keV, the spectrometer has been coupled to large γ-ray detector arrays (CLARA, AGATA) in order to separate the excited states of the final fragments.…”

“…Figure 12. Mass spectra of the most intense isotopic chains produced in the48 Ca + 64 Ni reaction. The mass spectra analyzed by the PRISMA spectrometer are plotted as a function of the number of transferred neutrons (reproduced with permission from[47,48]).…”