0000000000999261
AUTHOR
M. Ayranov
Be7(n,α)He4Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN
The energy-dependent cross section of the (7)Bed(n,alpha)He-4 reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of Be-7 and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure Be-7, and a specifically designed experimental setup. Coincidences between the two alpha particles have been…
Measurement of the Be7(n,p) cross section at thermal energy
The Be7(n,p) cross section was measured with an ion-implanted Be7 target at a thermal neutron beam of the research reactor LVR-15 in Řež. The cross section to the ground state of Li7 is σ(n,p0)=43800±1400b and the cross section to the first excited state of Li7 is σ(n,p1)=520±260b.
Measurement of the 7Be(n,p) cross section at thermal energy
The 7Be(n,p) cross section was measured with an ion-implanted 7Be target at a thermal neutron beam of the research reactor LVR-15 in Řež. The cross section to the ground state of 7Li is σ(n,p0)=43800±1400b and the cross section to the first excited state of 7Li is σ(n,p1)=520±260b.