Project information
Correlated Unresolved-Resonance Modelling and Measurements

Nuclear energy, in both fission and emerging fusion systems, relies on accurate neutron transport calculations to ensure efficient operation, robust shielding, and high safety margins. A major source of uncertainty in these calculations is the unresolved resonance region (URR), where dense, overlapping nuclear resonances are represented statistically rather than explicitly. Current URR treatments in Monte Carlo transport codes capture fluctuations in total and partial cross sections through a discretized model inspired by measurements and quantum physics but lacks proper angular treatment. This limits the fidelity of simulations for systems where anisotropic scattering in the URR can affect neutron leakage, radiation dose monitoring, power distribution, and detector response.
This project will combine MIT’s expertise in neutron transport modelling and OpenMC development with the experimental and detector capabilities of Masaryk University and the Řež Research Centre in Czechia. Building on previous MIT work, which introduced a continuous probabilistic description of URR cross sections based on sampled resonance parameters, we will perform dedicated neutron transmission and scattering experiments on copper samples of varying thickness. These measurements will directly constrain the parameters of the URR statistical model, while coincident measurements of scattered neutron angles and associated photon signatures will provide the first experimental basis for extending the model to correlated scattering angular distributions.
MIT students will collaborate with Masaryk’s group in planning and executing measurements at Řež, and in analyzing the data to infer model parameters. The refined and extended URR model will be implemented and tested in OpenMC, reducing nuclear data uncertainties relevant to advanced fission reactors, fusion blankets, and shielding design.