Different aspects of nuclear structure and reaction mechanisms in the collision N-13+B-11

The reaction N-13 + B-11 has been investigated at two 13N beam energies: 29 .5 and 45 MeV, Charged particles and gamma rays emitted in the reactions ha ve been detected using a large array of silicon strip detectors and BaF2 sc intillators, respectively. Several reaction channels have been analysed wit h different aims. The proton transfer reaction B-11(N-13, C-12)C-12 to various excited states of C-12 has been studied to obtain information on the N-13(g.s.) structure . The excitation energy of the Mg-24 compound nucleus was in the region where several resonances occur in the C-12 + C-12 system. The six-alpha decay of the Mg-24 intermediate system has been studied. Some of these events have been identified as coming from the break-up of two C-12* in the 3(1)(-)-3(1 )(-) and 3(1)(-)-0(2)(+) states. The total fusion cross section has also been extracted from the data. In or der to extract information on the isospin purity/mixing in Mg-24 at high ex citation energy (E-x similar to 47 MeV), the GDR gamma emission from this s elf-conjugate nucleus has been studied. A comparison of gamma spectra has b een undertaken for the reactions N-13 + B-11 and N-14 + B-10. (C) 2001 Else vier Science B.V, Ail rights reserved.