Oxides for D–T neutron yield measurements by activation techniques on fusion devices

Highlights: ► The 16O(n,p)16N reaction discriminates D–T-neutrons against scattered neutrons. ► Small oxide samples may be used for D–T-neutron yield monitoring. ► They are suitable for successive measurements from 0.1 to 10 s fusion pulses. -- Abstract: The 16O(n,p)16N activation reaction, completely discriminating neutrons with their energy over the effective threshold energy of 10.2 MeV, is shown to be ideal for monitoring the D–T fusion source neutrons. Neutronic and activation analyses are performed to evaluate operational activity of several material oxide samples as B2O3, BeO, CaO, Fe2O3 or TiO2 in comparison with ordinary metal foils and water volumes. It is shown that due to relatively high specific oxygen nuclear densities small pieces of oxide materials of ∼1 g by weight or even lower to be implemented with present activation systems are suitable for D–T neutron yield measurements from fusion pulses of ∼0.1 s up to ∼10 s duration and also for the D–T neutron flux determination in operation regimes of 60 s or more