Espectrometria de nêutrons em um acelerador cíclotron utilizando o sistema de esferas de Bonner e detectores termoluminescentes

The neutron spectrum can provide a great variation in energy in the same environment and some experimental methods have been developed to determine the spectral distribution as a function of energy. To carry out this task, the neutron spectrometry perform a fundamental role in determining the neutron fluence (ΦE(E)). The spectrum information allows the determination of others radiological quantities such as Ambient Dose Equivalent [H*(10)]. However, the characterization of the neutron field is a complex problem due to the occurrence of the peculiar interactions of neutrons with matter. In this study, the energy spectra of neutrons were obtained by the Bonner Sphere Spectrometer (BS), such system consists of six levels of polyethylene with high density and different diameters. The aim of this study is to evaluate the use of thermoluminescent detector (TLD) as a detector of thermal neutrons. Ten thermoluminescent detectors (TLD) were placed in the center of each ball, five 6LiF:Mg,Ti and five 7LiF:Mg,Ti, also known as TLD600 and TLD700, respectively. These detectors were chosen for good reproducibility and low sensitivity, which allows its use in fields of high intensity. The results of this study show that combination of TLDs embedded in an EB system can be used in neutron spectrometry achievement in fields of high intensity, as it occurs in the vicinity of accelerators cyclotrons.