Measurements of leakage neutron spectra from a high-energy accumulation ring using Extended Range Bonner Sphere Spectrometers

Abstract

Abstract Within the INFN–UAB cooperation, an experimental neutron spectrometry exercise was organized in DAΦNE, the high-energy Φ-meson producing accelerator (Φ-factory) of the INFN–Frascati National Laboratories. Particularly, the workplace neutron fields produced by a 510 MeV positron beam accumulated in the DAΦNE ring were characterized. As suitable instruments, the INFN and UAB Extended Range Bonner Sphere Spectrometers (ERBSS) were employed. These systems rely on different central detectors and have different sets of extended-range spheres. The experimental data were unfolded with the FRUIT unfolding code, especially designed for workplace measurements in absence of detailed pre-information on the neutron field. This analysis allowed studying the high-energy (>10 MeV) component of the neutron fields and assessing the performance of the two different ERBSS in this energy domain. Besides the discussion on ERBSS, this paper presents experimental data that may be used in radiation protection of high-energy positron beams.