HOTNES (HOmogeneous Thermal NEutron Source): A new design of thermal neutron irradiation facility

by Roberto Bedogni (LNF)

Friday 30 Jun 2017, 10:00 → 11:30 Europe/Rome

ENEA Aula B. Brunelli (LNF INFN)

A new design of thermal neutron irradiation facility, called HOTNES (HOmogeneous Thermal NEutron Source), was prototyped within the INFN-LNF / ENEA-Frascati collaboration. HOTNES is a polyethylene assembly, with about 70 cm × 70 cm square section and 100 cm height, including a large, cylindrical cavity with diameter 30 cm and height 70 cm. The facility is supplied by a 241Am-B source located on the cavity bottom. A specially studied combination of reflecting and attenuating parts produces constant values of fluence rate over irradiation planes as large as 30 cm in diameter. By varying the irradiation plane, the thermal fluence rate can be varied from about 700 cm-2 s-1 to 1000 cm-2 s-1. The facility design, previously optimized by Monte Carlo simulation, was experimentally verified. The main features of the HOTNES facility and the neutron field characterization will be presented.