Περίληψη:
The study of reactions induced by exotic weakly bound nuclei at energies
around the Coulomb barrier had attracted a large interest in the last
decade, since the features of these nuclei can deeply affect the
reaction dynamics. The discrimination between different reaction
mechanisms is, in general, a rather difficult task. It can be achieved
by using detector arrays covering high solid angle and with high
granularity that allow to measure the reaction products and, possibly,
coincidences between them, as, for example, recently done for stable
weakly bound nuclei [1, 2]. We investigated the collision of the
weakly bound nucleus Be-7 on a Ni-58 target at the beam energy of 1.1
times the Coulomb barrier, measuring the elastic scattering angular
distribution and the energy and angular distributions of He-3 and He-4.
The Be-7 radioactive ion beam was produced by the facility EXOTIC at
INFN-LNL with an energy of 22 MeV and an intensity of similar to 3x10(5)
pps. Results showed that the He-4 yeld is about 4 times larger than He-3
yield, suggesting that reaction mechanisms other than the break-up
mostly produce the He isotopes. Theoretical calculations for transfer
channels and compound nucleus reactions suggest that complete fusion
accounts for (41 +/- 5%) of the total reaction cross section extracted
from optical model analysis of the elastic scattering data, and that
He-3 and He-4 stripping are the most populated reaction channels among
direct processes. Eventually estimation of incomplete fusion
contributions to the He-3,He-4 production cross sections was performed
through semi-classical calculations with the code PLATYPUS [3].
Συγγραφείς:
Torresi, D.
Mazzocco, M.
Acosta, L.
Boiano, A.
Boiano,
C.
Diaz-Torres, A.
Fierro, N.
Glodariu, T.
Grilj, L. and
Guglielmetti, A.
Keeley, N.
La Commara, M.
Martel, I. and
Mazzocchi, C.
Molini, P.
Pakou, A.
Parascandolo, C. and
Parkar, V. V.
Patronis, N.
Pierroutsakou, D.
Romoli, M. and
Rusek, K.
Sanchez-Benitez, A. M.
Sandoli, M.
Signorini, C.
and Silvestri, R.
Soramel, F.
Stiliaris, E.
Strano, E. and
Stroe, L.
Zerva, K.
