Direct surface-transfer reaction to the continuum states induced by a 1760 MeV 40Ar beam on 27Al and natTi target nuclei

Properties of projectile-fragments in the 40Ar+27Al reaction at 44 A MeV. Comparison with a multisequential decay model

“…The insert shows, the 8 Be 3.04 MeV excited level and, at lower relative momenta, a peak attributed to the 9 Be 2.43 MeV excited level. b) Relative momentum distribution in the forward wall between an α-particle and a reconstructed 8 Be nucleus in its ground state. The two main excited levels in the primary 12 C nucleus are shown.…”

“…This decrease is much smaller for the light ion region around Z=6, and is not present for light particles, Z<3. Ions with charge exceeding the charge of the projectile are also observed since reactions with exchange of a few nucleons between target and projectile are still important [8] at these high energies. For the light particle yield (Z≤2) and for Z=3 fragments, we have considered only the component with velocity close to the projectile velocity.…”

“…This velocity reaches a maximum value at the Z of the projectile. Fragments with Z>18, result from the pick-up of few nucleons from the target, leading to a slowing down of the projectile [8]. For Z<18, a minimum is reached in the region of light ions, around Z=7, and then the velocity increases again for lighter ions.…”

“…We start from the experimental evidence that a huge quantity of α-particles (≈10% of the α-particles detected on the wall) are well correlated to form 8 Be, either in its ground or excited states. Without going into details (see [10] and references therein), the experimental correlation function is constructed by dividing the coincidence yield by the yield of uncorrelated events.…”

“…The peak at ≈45 MeV/c is generally attributed to the neutron unstable level of 9 Be at 2.43 MeV. We have reconstructed the spatial and kinematic properties of the primary 8 Be ions in its ground-state and then looked for further coincidences between this primary 8 Be and α-particles or protons. The correlation function (not divided by the uncorrelated yield) for 8 Be and α-particles is shown in Fig.…”