Actas de congresos
Monte Carlo calculation of the response matrix of a Bonner spheres spectrometer
Fecha
2008-10Autor
Vega Carrillo, Héctor René
Gallego Díaz, Eduardo
Manzanares Acuña, Eduardo
Lorente, Alfredo
Institución
Resumen
The Bonner spheres spectrometer is utilized to estimate the neutron spectrum of neutrons from
thermal up to several MeV neutrons. Its response is increased to few GeV neutrons by introducing large Z
materials as inner shells. To use the spectrometer a matrix response and an unfolding method are required; these
are crucial to assure the quality of spectrometer output. The response matrix of a Bonner sphere spectrometer
was calculated by use of the MCNP code. As thermal neutron counter the spectrometer has a 0.4 Ø × 0.4 cm2
6LiI(Eu) scintillator which is located at the centre of a set of polyethylene spheres. The response functions were
calculated for 0, 2, 3, 5, 8, 10, and 12 inches-diameter polyethylene spheres for neutrons whose energy goes
from 10-8 to 100 MeV. For energies from 10-8 to 20 MeV the MCNP4C code was utilized while for neutrons
from 20 to 100 MeV calculations were carried out with MCNPX code. The response functions were compared
with those reported in the literature.