Application of CR-39™ SSNTD with a boron converter for the characterization of the external neutron beam of a powder diffractometer

In this work, the solid state nuclear track detector (SSNTD) CR-39™ has been used in combination with a boron converter screen for the characterization of the neutron distribution in the neutron powder diffractometer of the Es-Salam research reactor. A relationship between the track density in the CR-39™ and the neutron flux distribution has been established by a mathematical development. Good agreement was found between the distribution of the thermal neutron flux determined by CR-39™ detector and the distribution measured by the activation of Dysprosium foils. On the other hand, the degree of homogeneity of the neutron beam has been determined by the SSNTD and direct neutron radiography techniques. The results obtained by both techniques showed a depression of the flux at the left bottom region of the beam.