Three-Dimensional Monte Carlo Calculations of Nuclear Heating in CIT and Comparisons with Results from Simpler Models

In the Compact Ignition Tokamak (CIT), significant nuclear heating results from the neutron and γ interactions in structural components near the plasma and it affects their thermo-mechanical behaviors. Approximate nuclear heating distributions have previously been obtained with 2-D discrete ordinate models¹ and a simple formulation based on 3-D ray-tracing and 1-D discrete ordinate models². To reduce the geometric uncertainties in these calculations, we have constructed a set of detail 3-D Monte Carlo models for rigorous calculations. The results obtained from these models are used as benchmarks to evaluate the accuracy and relative merits of the simpler models.