Overview of interpretive modelling of fusion performance in JET DTE2 discharges with TRANSP

Year: 2023

Type: article

Abstract: In the paper we present an overview of interpretive modelling of a database of JET-ILW 2021 D-T discharges using the TRANSP code. The main aim is to assess our capability of computationally reproducing the fusion performance of various D-T plasma scenarios using different external heating and D-T mixtures, and to understand the performance driving mechanisms. We find that interpretive simulations confirm a general power-law relationship between increasing external heating power and fusion output, which is supported by absolutely calibrated neutron yield measurements. A comparison of measured and computed D-T neutron rates shows that the calculations’ discrepancy depends on the absolute neutron yield. The calculations are found to agree well with measurements for higher performing discharges with external heating power above ∼20 M W , while low-neutron shots display an average discrepancy of around +40% compared to measured neutron yields. A similar trend is found for the ratio between thermal and beam-target fusion, where larger discrepancies are seen in shots with dominant beam-driven performance. We compare the observations to studies of JET-ILW D discharges, to find that on average the fusion performance is well modelled over a range of heating power, although an increased unsystematic deviation for lower-performing shots is observed. The ratio between thermal and beam-induced D-T fusion is found to be increasing weakly with growing external heating power, with a maximum value of ≳ 1 achieved in a baseline scenario experiment. An evaluation of the fusion power computational uncertainty shows a strong dependence on the plasma scenario type and fusion drive characteristics, varying between ±25% and 35%. D-T fusion alpha simulations show that the ratio between volume-integrated electron and ion heating from alphas is ≲ 10 for the majority of analysed discharges. Alphas are computed to contribute between ∼15% and 40% to the total electron heating in the core of highest performing D-T discharges. An alternative workflow to TRANSP was employed to model JET D-T plasmas with the highest fusion yield and dominant non-thermal fusion component because of the use of fundamental radio-frequency heating of a large minority in the scenario, which is calculated to have provided ∼10% to the total fusion power.

Source: Nuclear Fusion

DOI: 10.1088/1741-4326/ad0310

Institutions: Culham Science Centre, United Kingdom Atomic Energy Authority, National Agency for New Technologies, Energy and Sustainable Economic Development, University of Padua, Istituto Nazionale di Fisica Nucleare, Institute for the Science and Technology of Plasmas, Princeton Plasma Physics Laboratory, Forschungszentrum Jülich, Oak Ridge National Laboratory, Royal Military Academy, Barcelona Supercomputing Center, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA Cadarache, Max Planck Institute for Plasma Physics, Institució Catalana de Recerca i Estudis Avançats, University of Milano-Bicocca

Language: English

Topic: Magnetic confinement fusion research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,400

Funders: EUROfusion, European Commission, Generalitat de Catalunya, Barcelona Supercomputing Center, Euratom Research and Training Programme, Engineering and Physical Sciences Research Council, Consejo Superior de Investigaciones Científicas, Agencia Estatal de Investigación

OpenAlex ID: W4388409405