engleski

Single and pair neutron transfers at sub barrier energies

Multinucleon transfer cross sections in the 96Zr+40Ca system have been measured, in inverse kinematics, at bombarding energies ranging from the Coulomb barrier to ~25% below. Target-like recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental data for one and two neutron transfer channels have been compared with semiclassical microscopic calculations. For the two neutron transfer channels the relevance of the transitions to the ground state and to the 0+ excited states of 42Ca are discussed by employing, for the reaction mechanism, the successive approximation. It is found that the transition to the 0+ state at ~6 MeV, whose wavefunction is dominated by the two neutrons in the 2p3/2 shell, is much larger than the ground state one. The comparison with the inclusive data reveals that transitions to states with high multipolarity and non-natural parity are important. This suggests that two-particle correlations, other than 0+, have to be incorporated in the transfer process.

heavy ion tranfer reaction; sub-barrier energies; nucleon-nucleon correlation

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