Neutron spectrometry around a high-energy electron-positron collider using a multi-sphere system with passive detectors

Abstract

At the INFN LNF (Frascati), the 510 MeV electron–positron collider DAΦNE is operating since 1997. The neutron fields in the areas around the accelerator were characterised using a Bonner sphere system. The sensitivity of the system was extended up to 10² MeV by means of a lead loaded 12^″ sphere. Recently developed thermoluminescence dosemeters (TLDs), with improved neutron sensitivity and gamma rejection properties, were used as central detectors. The new TLD-based spectrometric system was characterised by irradiation in quasi-monoenergetic or radionuclide neutron fields. In addition, numerical verifications with the Monte Carlo code MCNP were performed. This work addresses this new TLD-based spectrometer and presents the spectral measurements performed in a point of test around DAΦNE. The results are compared with those obtained, in the same point, with a previously validated Bonner sphere system based on an active ⁶LiI(Eu) scintillator.