7Be,8B+208Pb
Elastic Scattering at
Intermediate Energies,
J. Wang, Institute of
Modern Physics,
Chinese Academy of Sciences,
P. R. China
− The experiment of measuring elastic scattering angular
distribution of 7Be,
8B on 208Pb target was carried out at
Radioactive Ion
Beam Line at Lanzhou (RIBLL) at center-of-mass energies of
121MeV and 164MeV
respectively. As opposed to the situation for neutron halo
nuclei 6He
and 11Be (A. Di Pietro et al.,
PRL 105,
022701(2010)), for which
the Coulomb Nuclear Interference Peak (CNIP) are obviously
suppressed comparing
to the stable nuclei, the CNIP for 8B is not
suppressed and is a
little higher than that for 7Be. The optic model
fitting are done
with the FRESCO code and the total reaction cross sections and
fusion cross
sections are deduced. The shallow depth of imaginary part of the
optical
potential are needed in order to fit the CNIP for 8B.
It indicates
that the 8B is easy to breakup. The deduced total
reaction cross
section for 8B is also larger than that for 7Be. The
CCDC
calculations are also performed for 7Be and 8B.
The
calculations reproduce the angular distribution very well for 7Be,
but
not for 8B. This unusual behavior of the elastic
scattering
cross section in the CNIP region for 8B comparing to
the neutron
halo nuclei could be due to the difference of structure between
the proton halo
(charged halo) and neutron halo (uncharged halo).