A Bonner Sphere Spectrometer based on a large ~6LiI(Eu) scintillator: Calibration in reference monoenergetic fields

摘要

A Bonner Sphere spectrometer employing a large, 11 mm diameter x 3 mm thickness, (LiI)-Li-6(Eu) scintillator (LL-BSS), was assembled. The purpose was to produce a BSS similar in sensitivity to those based on He-3 sensors, but using alternative sensors. With respect to the traditional BSS based on the 4 mm (diameter) x 4 mm (height) (LiI)-Li-6(Eu), this new BSS is a factor of 3 more sensitive. LL- BSS response matrix, determined with MCNPX, was experimentally evaluated with monoenergetic reference neutron fields of 144 keV, 565 keV and 1.2 MeV available at NPL (Teddington, UK). The results of the experiment confirmed the correctness of the response matrix within an overall uncertainty lower than +/- 2%.