Teste | Abstract: 160-1 | ||||
Abstract:The 241AmLi neutron source is classified as a low energy source and is used for neutron spectrometry and dosimetry, fluence calibration of neutron monitors, and active non-destructive testing techniques for nuclear and nonproliferation safeguards. However, there are still a number of barriers to the use of this source in most laboratories. This is because its physical properties are still poorly documented and vary between manufacturers, as well as complications in the physical order of magnitude for neutron generation. Therefore, the purpose of this thesis is to characterize the neutron energy spectrum of the 241AmLi isotope source using neural network based technology, to obtain the radioprotection quantities of ambient and individual dose equivalents, and to discuss the problems of the source. Bonner multisphere spectrometry was used, the first prototype of which was introduced in 1960. The system consists of polyethylene spheres (moderators) of different diameters and, due to its spherical (symmetrical) geometry, allows a practically isotropic response to obtain the average energy, fluence rate and radioprotective quantities such as the individual dose equivalent and the environment. Source measurements were performed with six different polyethylene spherical moderators around a 6LiI(Eu) scintillator type thermal neutron detector. From this, the neutron spectrum was obtained using the LN-developed NeuraLN software, which is an artificial intelligence using the neural network technique. A mean energy result in agreement with the literature was obtained, and it is therefore possible to propose a possible mean energy pattern for the 241AmLi source. Keywords: neutron, metrology, dosimetry, physics |