E. Costanzo

A procedure for the analysis of the data of a three body nuclear reaction

Abstract In a three body nuclear reaction, usually only two of the three reaction products are detected and identified. Complete information on the reaction is deduced by conservation laws. This procedures cannot be used when the reaction takes place on unknown target nuclei, e.g. on target contamination. A data treatment procedure is presented here which allows for the determination of the mass of the undetected particle and of the Q -value of the reaction.

α-5He decaying states and the ground-state rotational band of 9Be

In a measurement of the 9Be(7Li, 7Liα)αn reaction at Ei = 52 MeV it is unambigously established for the first time that the 9Be excited states around 6.5 and 11.3 MeV decay into the α + 5He channel. This fact may support previous claims that the 11.3 MeV state is also a member of the ground-state rotational band.

7Li quasi-free scattering off the α-cluster in 9Be nucleus

Abstract. Spectra of coincident charged particles from the reactions induced by a 52 MeV 7Li beam incident on a beryllium target were measured. Strong contributions of the 7Li quasi-free scattering off the α-cluster in 9Be nucleus were observed. This observation supports the conclusions from the study of complete fusion of weakly bound light nuclei at low energies that the “fragility” of the nuclei makes their fusion less probable.

Resonant effects in the12C+12C?8Be gs +16O gs reaction aroundE cm=32.5 MeV

The12C+12C→8Begs+116Ogs reaction has been studied at c.m. energies of 27.9, 32.5 and 35.0 MeV. The energy dependence of the cross section is consistent with a resonant behaviour like the one observed for two12C nuclei excited in a very deformed state in the final channel. The angular distributions for the two reactions show also a similar oscillatory behaviour. The analysis suggests that the reaction proceeds through the formation of an intermediate state with a complex nature, involving largely deformed configurations as well as almost spherical ones.

Resonances in the12C(12C,8Beg.s.)16O reaction and rotational states in24Mg

SummaryThe results of a set of experiments on the12C+12 C →8 Beg.s. +16 O excitation function between 20 and 36 MeV cm. beam energy are summarized and discussed. A set of 1 MeV wide resonances shows up in the energy range investigated, all of them following the rotational rule with a coefficient of inertia consistent with a α -16O - α configuration.

Evidence for Excitation of 24Mg Resonant States through the 12C(16O, 12C12C)4He Reaction at 85 MeV

The population of 12C-12C molecular resonances in the 16O + 12C interaction has been studied in a kinematically complete experiment at 85 MeV. It was observed that the 12C-12C-α final state is mostly due to projectile excitation followed by α emission. Nevertheless in the region of higher 12C-α relative energy evidence is found for excitation of high-lying 24Mg states, decaying into the 12C-12C system.

16O break-up on24Mg at 84.6 MeV

SummaryA coincidence experiment was performed on the24Mg(16O,12Cα) reaction at an incident energy of 84.6 MeV. The measured relative energy spectra show the excitation of16O selected states decaying into the α-12C channel.

The 12 C + 12 C → 8 Be gs + 16 O gs reaction at E cm =27 to 36 MeV

The12C+12C→8Begs+16Ogs reaction has been experimentally investigated at c.m. energies between 27 and 36 MeV. A resonance is present at 32.5 MeV,i.e. at the same energy of the resonance previously observed [1] in the12C(02+)+12C(02+) exit channel, but its width is about three times narrower. Moreover the data indicate an enhancement of the cross section at a c.m. energy close to 29 MeV. These results are discussed and compared to the predictions of the Band Crossing Model obtained for different exit channels of the12C+12C reaction.