Neutron yield monitors for the divertor tokamak test (DTT) facility: Detector set, expected performance and integration

• 16 Fission Chambers and 6 BF 3 counters used to monitor DD+DT neutron yield for DTT. • EJ301 liquid scintillator and two sCDs designed for DT neutron yield measurements. • Detector performances estimated via MCNP simulations and detector efficiency data. • DD+DT monitors achieve ≤3 % error with time resolution ≤100 ms across full yield range. • DT monitors achieve ≤3 % error; time resolution limited by DD neutron sensitivity. The present work provides a description of the Neutron Yield Monitors (NYM) planned for installation at the Divertor Tokamak Test (DTT) facility for the measurement of the neutron yield rate. The proposed system is designed to measure both the emission of 2.45 MeV neutrons and that of 14.1 MeV neutrons due to triton burn-up reactions and is composed by 235 U fission chambers with four different masses of fissile coating, BF 3 counters with two different efficiencies, a liquid scintillator and two single-crystal diamond matrices of different thicknesses. The paper encompasses the design of the different detectors and of the associated acquisition chain. The capability of the whole detector set to cover the expected range of the DTT 2.45 MeV and 14.1 MeV neutron yield rate within fixed values of precision and time resolution is also addressed combining MCNP calculations of the neutron flux at the detector positions and estimates of the detector efficiencies.