Simulation of the DD, TT and DT JET Neutron Streaming Experiments with TRIPOLI-4® Monte-Carlo code

Abstract

The DD, TT and DT neutron streaming experiments (NEXP-STRE) in the fusion facility JET are here simulated with TRIPOLI-4® Monte-Carlo code. Specifically, we present the results from the simulation of the DD (2019) and the later TT and DT (2021) campaigns. The last version of TRIPOLI-4® code, developed by CEA, is provided with an innovative variance reduction technique based on the adaptive multi-level splitting (AMS) methodology for particle transport which ensures reliable results in very detailed, complex and vast geometry. Furthermore, a specific tool, developed by CEA, is used to automatically convert MCNP geometry into TRIPOLI-4® geometry format, which allows to perform fast and reliable comparisons between the results obtained by the mean of both calculation tools. The JET 360° MCNP model is used as a basis for creating the TRIPOLI-4® geometry. The neutron flux and doses in thermoluminescent detectors (TLDs) and reaction rates in activation foil (AF) detectors are computed for various positions in the experimental hall. A comparison of our results with the experimental values (2019 DD - 2021 TT campaigns) and the MCNP computed values (all campaigns) is presented. The AMS results crucial for obtaining statistically reliable quantities with TRIPOLI-4® code.