Development and validation of a forward 0.7–4 MeV quasi-monoenergetic neutron capability at the CN Van de Graaff of LNL

Here is the abstract exactly as it appears in your published paper. > **Abstract:** The CN Van de Graaff accelerator of INFN-LNL provides forward-angle quasi-monoenergetic neutrons in the 0.7–4 MeV range via the (^{7})Li(p,n)(^{7})Be reaction on thin metallic lithium targets. This work describes the development and experimental validation of this forward neutron capability, combining comparisons of commonly used transport tools with time-of-flight (ToF) measurements. > > Neutron yields calculated with EPEN, FLUKA, MCNPX, and PINO are compared over the CN energy range in order to assess model-dependent variations relevant for fluence estimates. For zero incident-energy spread, a mutually consistent set of transport calculations agrees within ±5% and is used as a practical reference for normalisation. The effect of incident-energy convolution on the predicted yields is examined. > > Time-of-flight measurements performed using a sub-nanosecond secondary pulsing system verify the timing structure and forward-angle kinematics of the quasi-monoenergetic neutron component at the detector position, with neutron arrival times consistent with the expected forward kinematics within the experimental resolution. > > Using measured proton currents and transport calculations based on this reference set, forward neutron fluences at the device position are estimated with an overall uncertainty of approximately 9%, including contributions from current integration, target thickness, and geometry. > > A short device irradiation, carried out in parallel with the ToF campaign, demonstrates measurable response under CN beam conditions and confirms the practical usability of the beam for low-MeV neutron studies. Together, these results establish the current operational performance of the CN 0° forward quasi-monoenergetic neutron capability in the 0.7–4 MeV range and identify the steps required toward routine calibrated operation.