Direct evidence for the breakdown of the N = 8 shell closure in 12Be
1National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 and Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
Abstract:
Partial cross sections and corresponding momentum distributions have been studied in the one-neutron knockout reaction ( 12Be,11Be+gamma) on a 9Be target at 78 MeV/nucleon. The resulting spectroscopic factors for the only two bound states of 11Be are 0.42+/-0.06 ( 1/2(+)) and 0.37+/-0.06 ( 1/2(-)), where the errors are experimental only. This result shows that N = 8 is not a good closed shell in the neutron-rich 12Be and that the last neutron pair is two-thirds in the ( 1s(2)+0d(2)) intruder configuration.
Related Concept Videos
The Energies of Atomic Orbitals
Electron Configuration of Multielectron Atoms
Nuclear Stability
To hold positively charged protons together in the...
Nuclear Binding Energy
Nuclear Fission
Nuclear Transmutation


