Abstract

VALERO-LUNA, C. et al. Neutron area monitor with passive detector. Rev. mex. fis. [online]. 2012, vol.58, n.3, pp.262-264. ISSN 0035-001X.

Using Monte Carlo methods the responses of a passive neutron monitor area has been calculated. To detect thermal neutrons the monitor has a gold foil that is located at the center of a polyethylene cylinder. Impinging neutrons are moderated by polyethylene nuclei reaching the gold foil with the energy to induce activation through the reaction ¹⁹⁷Au(nγ) ¹⁹⁸Au. The ¹⁹⁸Au decays emitting 0.411 MeV gamma rays with a half life of 2.7 days. The induced activity is intended to be measured with a gamma-ray spectrometer with a 3'' øX3'' NaI(T1) scintillator and the saturation activity is correlated to the ambient dose equivalent. The response was calculated for 47 monoenergetic neutron sources ranging from 1x10^-9 to 20 MeV. Calculated fluence response was compared with the response of neutron monitor area LB 6411.

Keywords : Neutrons; Monte Carlo; activation detectors.