Interpretative TRANSP analysis of JET baseline scenario: performance dependence on plasma kinetic profiles

The JET baseline scenario performances of the recent Deuterium-Tritium campaigns performed in 2021 (DTE2) and 2023 (DTE3) have been studied using the TRANSP code. This study focuses on the performance dependence on kinetic plasma parameters, emphasising the differences between the JET pulse #99512 from DTE2 and its counterpart JET pulse #104661 from DTE3. The auxiliary heating system in JET pulse #99512 did not operate at its full capacity, whereas in JET pulse #104661, it was possible to achieve additional 5.8 MW (∼25%). However, the expected enhancement in neutron production was not achieved. Detailed simulations reveal that the underperformance is due to a different combination of plasma dilution by impurities and main ion mixture compared to the conditions obtained in JET pulse #99512. The study demonstrates that a comprehensive modelling approach, integrating impurity effects and main ion composition, is essential to accurately reproduce the experimental neutron yield. The findings highlight the significant influence of spatial isotope distribution on neutron production, providing critical insights for optimizing performance in future fusion devices, including ITER.