Measurements of the neutron spectrum energy in the IPEN/MB-01 reactor core

Abstract

This work presents the results of neutron spectrum measurements at central position of the IPEN/MB-01 reactor core. For this purpose has been used several activation foils (Au, Sc, U, Mg, Ti, Ni, and In Foils) that have been irradiated at central position of the reactor core (standard rectangular configuration 28 × 26 fuel rods) in the maximum power level (100 watts). After this one the foils were counting at HPGe solid state detector (gamma spectrometry). The nuclear reaction rates experimental results (saturated activity per target nucleus) is together with an initial approach to the neutron reactor spectrum (estimated by reactor physics cellular codes) the main data to obtain the most appropriated neutron spectrum at the irradiation position by interactive adjustment process using the unfolding SANDBP code. The results obtained were (5.1312±0.1609).10(9) n/cm².s to the integral neutron flux, (9.8087±0.4974).10(8) n/cm² to the thermal neutron flux, (3.2272 ± 0.4378).10(9) n/cm².s to the intermediate neutron flux and (1.9040 ± 0.6390).10(9) n/cm².s to the fast neutron flux. These results are important and may be used to check and validate reactor physics codes and several nuclear data libraries.