Speaker
Description
This work presents a comprehensive assessment of radiation damage and transmutation gas production in the upgraded operating target of the ISIS Target Station 1 (TS1) spallation neutron source under irradiation, using the FLUKA Monte Carlo code. Previous benchmarking activities have validated the FLUKA model of the ISIS TS1 Target Reflector and Moderator (TRAM) assembly against measurable quantities such as energy deposition, decay heat, and radionuclide inventories, demonstrating its reliability for radiological and thermo-mechanical analyses.
Building on this validated framework, the present study focuses on irradiation-induced material degradation in the tungsten core and tantalum cladding of the target plates. Radiation damage is quantified in terms of displacements per atom (NRT-DPA, DPA-SCO, ARC-DPA) and helium and hydrogen production, accounting for contributions from primary protons as well as secondary neutrons and charged particles generated in the spallation cascade.
The analysis delivers a plate-by-plate evaluation of secondary particle fluence, DPA accumulation, and gas production, enabling a spatially resolved characterisation of irradiation conditions and identification of the most critical regions in terms of material degradation.
Finally, the effect of accumulated irradiation damage on thermal conductivity is evaluated by combining the NRT-DPA values predicted by FLUKA with established correlations from the literature linking NRT-DPA to thermal conductivity degradation. The resulting estimates are then compared with experimental data from a measurement campaign conducted at ISIS, aimed at investigating the decay heat and thermal properties of the target following a defined irradiation period.
The predicted reduction in thermal conductivity shows good agreement with the measured values within the uncertainties, supporting the robustness of the modelling approach in consistently linking high-energy particle transport calculations, radiation damage metrics, and the resulting macroscopic material performance in spallation targets.
| Other | It could also be presented in Radiation Transport Code and Nuclear Data session |
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