Vega Carrillo, Héctor René; Donaire, I.; Gallego Díaz, Eduardo; Manzanares Acuña, Eduardo; Lorente, Alfredo; Iñiguez de la Torre, María Pilar; Martin Martin, Alonso; Gutiérrez Villanueva, José Luís
Resumen:
Se calcul´o la matriz de respuesta de un espectr´ometro de Esferas de Bonner utilizando los c´odigos Monte Carlo MCNP 4C y MCNPX 2.4.0.
El detector de neutrones t´ermicos del espectr´ometro es un centellador cil´ındrico, 0.4 cm ×∅ 0.4 cm, de 6LiI, que se ubica en el centro de
esferas de polietileno. La respuesta se obtuvo para esferas cuyo di´ametro es 0, 2, 3, 5, 8, 10 y 12 pulgadas y para fuentes monoenerg´eticas
de neutrones de 2.50E(-8) to 100 MeV. La matriz se calcul´o para 23 fuentes monoenerg´eticas, las funciones de respuesta se interpolaron
a 51 energ´ıas que se compararon con las correspondientes reportadas en la literatura. Se encontr´o que ambas matrices son coincidentes,
excepto para neutrones de baja y alta energ´ıa; esta diferencia es atribuida a las condiciones de irradiaci´on utilizadas en ambos estudios y a
las secciones eficaces.
Descripción:
The response matrix of a Bonner sphere spectrometer was calculated using MCNP 4C and MCNPX 2.4.0 codes. As thermal neutron detector
a 0.4 cm ×∅ 0.4 cm 6LiI which is located at the center of a set of polyethylene spheres. The response was calculated for 0, 2, 3, 5, 8, 10, and
12 inches-diameter polyethylene spheres for neutrons whose energy goes from 2.50E(-8) to 100 MeV. The response matrix was calculated
for 23 neutron energies, the response functions were energy-interpolated to 51 neutron energies and were compared with a matrix response
reported in the literature, in this comparison both response matrices are in agreement. The main differences were found in the bare detector
and are attributed to the irradiation conditions and cross sections, for the other detectors the differences are due to the cross sections libraries.