Interpretive modelling of fusion performance in JET DTE2 discharges with TRANSP

Fusion power measurements are an essential tokamak operational parameter, therefore it is important to develop and validate integrated modelling tools capable of interpreting the fusion performance of current experiments, and extrapolate to ITER-like conditions. A range of plasma scenarios with varying fusion performance were tested in JET's recent deuterium-tritium campaign (DTE2), providing an opportunity to benchmark integrated modelling codes. We present an overview of interpretive modelling of over 80 JET DTE2 discharges using the TRANSP code. Our main aim is to assess the capability of reproducing the fusion performance of various plasma scenarios using different external heating and DT mixtures. We compare neutron rates measured by fission chambers and calculated ones, finding a strong dependency of the match between the two and absolute neutron rate. The calculations are found to agree with measurements for higher performing discharges with larger external heating power, while low-neutron shots have an average discrepancy of around + 40 %. A similar trend is found for the ratio between thermal and beam-target fusion, where larger discrepancies are seen in shots with beam-driven performance. We compare the observations to studies of JET's D and DTE1 campaigns, and assess uncertainties stemming from input diagnostics data.