Measurement of a fast neutron leakage spectrum from graphite cylinder driven by D-T generator

This paper deal with leakage measurements performed on a fusion DT generator using a graphite target. The main objective was to verify or refute the observed discrepancy between calculations and experiments at higher neutron energies. The measurements were performed using a well validated stilbene scintillation detector. The obtained spectrum was then compared with Monte Carlo calculations using the MCNP code and various nuclear data libraries. The results show a persistent discrepancy between the experiment and the calculations, regardless of the neutron source used and the concept of the experiment itself, especially in the energy range of 6.5–8.5 MeV and in energies above 11 MeV. The measurements thus serve as supplementary data to the reactor experiments carried out and point to the need for further refinement of the nuclear data of graphite in the fast neutron range.