The Li-8+He-4 -> B-11+n reaction inside the center- of- mass energy region E-cm = 0.5- 2.5 MeV, corresponding to the temperature range T-9 = 1-5, is of relevant interest in the fields of nuclear cosmology and nuclear astrophysics. In the context of Big Bang nucleosynthesis, it has been invoked to overcome the A = 8 mass gap; in r- process nucleosynthesis, it is considered a candidate precursor of seed nuclei. In this experimental work, the cross section, summed over all 11B final bound states, at the energy of 1.05 MeV in the center- ofmass system, is investigated by a correction- free projectile- correlated inclusive neutron measurement. The radioactive Li-8 beam delivered by the EXCYT facility at LNS- Catania is used to induce the inverse- kinematics reaction process. A zero- energy- threshold 4 pi detection system is used. Thanks to the improved experimental and analysis procedures, the result obtained in this work represents a strong argument to reopen the debate on the magnitude of the Li-8(alpha, n)B-11 reaction rate in explosive astrophysical environments.
The Li-8+He-4 -> B-11+n reaction inside the center- of- mass energy region E-cm = 0.5- 2.5 MeV, corresponding to the temperature range T-9 = 1-5, is of relevant interest in the fields of nuclear cosmology and nuclear astrophysics. In the context of Big Bang nucleosynthesis, it has been invoked to overcome the A = 8 mass gap; in r- process nucleosynthesis, it is considered a candidate precursor of seed nuclei. In this experimental work, the cross section, summed over all 11B final bound states, at the energy of 1.05 MeV in the center- ofmass system, is investigated by a correction- free projectile- correlated inclusive neutron measurement. The radioactive Li-8 beam delivered by the EXCYT facility at LNS- Catania is used to induce the inverse- kinematics reaction process. A zero- energy- threshold 4 pi detection system is used. Thanks to the improved experimental and analysis procedures, the result obtained in this work represents a strong argument to reopen the debate on the magnitude of the Li-8(alpha, n)B-11 reaction rate in explosive astrophysical environments.
Toward correction-free Li-8(alpha, n)B-11 data at the Gamow energy of explosive nucleosynthesis
CHERUBINI, SILVIO;LAMIA, LIVIO;MUSUMARRA, Agatino;ROMANO, Stefano;
2010
Abstract
The Li-8+He-4 -> B-11+n reaction inside the center- of- mass energy region E-cm = 0.5- 2.5 MeV, corresponding to the temperature range T-9 = 1-5, is of relevant interest in the fields of nuclear cosmology and nuclear astrophysics. In the context of Big Bang nucleosynthesis, it has been invoked to overcome the A = 8 mass gap; in r- process nucleosynthesis, it is considered a candidate precursor of seed nuclei. In this experimental work, the cross section, summed over all 11B final bound states, at the energy of 1.05 MeV in the center- ofmass system, is investigated by a correction- free projectile- correlated inclusive neutron measurement. The radioactive Li-8 beam delivered by the EXCYT facility at LNS- Catania is used to induce the inverse- kinematics reaction process. A zero- energy- threshold 4 pi detection system is used. Thanks to the improved experimental and analysis procedures, the result obtained in this work represents a strong argument to reopen the debate on the magnitude of the Li-8(alpha, n)B-11 reaction rate in explosive astrophysical environments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
