EUROfusion contributions to ITER nuclear operation

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A low beamlet divergence is crucial for the efficiency of the ITER-NBI systems, since it affects the transmission of the beam through the duct. There is a requirement of 7 mrad e-folding divergence for the ITER Heating Neutral Beam. Significantly higher divergences (10-15 mrad) have been observed in RF-source based experiments albeit at low beam energy. This could be the consequence of a broad perpendicular velocity distribution of the H-/D- particles before extraction. This paper explores this hypothesis and its implications for ITER. To estimate H-/D- perpendicular temperatures in the RF-driven BATMAN Upgrade test facility, spatially resolved measurements of the beam power density are compared with IBSimu calculations. The estimated perpendicular temperatures show a strong dependence on the source filling pressure, decreasing from approximately 4 eV at 0.3 Pa to 2 eV at 0.4 Pa. Ion-optics calculations of the ITER-HNB grid system are performed to evaluate whether the temperatures estimated in the BATMAN Upgrade test facility are tolerable in view of beam-grid interaction and beamline transmission. The beamline transmission is fairly insensitive to the perpendicular temperature, but the heat loads at the downstream grids increase with the perpendicular temperature.

Section: Introductionmentioning

confidence: 99%

Beam optics of RF ion sources in view of ITER’s NBI systems

den Harder,

Barnes,

Heinemann

et al. 2024

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Overview of T and D–T results in JET with ITER-like wall

Maggi,

Abate,

Abid

et al. 2024

In 2021 JET exploited its unique capabilities to operate with T and D-T fuel with an ITER-like Be/W wall (JET-ILW). This second major JET D-T campaign (DTE2), after DTE1 in 1997, represented the culmination of a series of JET enhancements – new fusion diagnostics, new T injection capabilities, refurbishment of the T plant, increased auxiliary heating, in-vessel calibration of 14MeV neutron yield monitors – as well as significant advances in plasma theory and modelling in the fusion community. DTE2 was complemented by a sequence of isotope physics campaigns encompassing operation in pure tritium at high T-NBI power. Carefully conducted for safe operation with tritium, the new T and D-T experiments used 1 kg of T (vs 100 g in DTE1), yielding the most fusion reactor relevant D-T plasmas to date and expanding our understanding of isotopes and D-T mixture physics. Furthermore, since the JET T and DTE2 campaigns occurred almost 25 years after the last major D-T tokamak experiment, it was also a strategic goal of the European fusion programme to refresh operational experience of a nuclear tokamak to prepare staff for ITER operation. The key physics results of the JET T and DTE2 experiments, carried out within the EUROfusion JET1 work package, are reported in this paper. Progress in the technological exploitation of JET D-T operations, development and validation of nuclear codes, neutronic tools and techniques for ITER operations carried out by EUROfusion (started within the Horizon 2020 Framework Programme and continuing under the Horizon Europe FP) are reported in [1], while JET experience on T and D-T operations is presented in [2].

Summary of the 29th IAEA fusion energy conference under the topics magnetic fusion experiments (EX) and innovative & alternative concepts (IAC)

Litaudon,

Mazon

2024

The paper provides a high level summary of the contributions given at the 29th International Atomic Energy Agency (IAEA) Fusion Energy Conference (FEC 2023) London, United Kingdom, 16–21 October 2023 (available at: https://iaea.org/events/fec2023) under the categories “Magnetic Fusion Experiments including validation” (EX) and “Innovative Alternative Concepts” (IAC) covering linear configuration, non-magnetic configurations, fusion-fission hybrids concepts…. For the category EX, the summary is limited to three sub-categories Heating Current Drive (EX-H&CD), Waves (EX-W), Stability (EX-S). The experimental results reported in this publication cover the period since the previous 28th FEC, which was a virtual event held from 10th to 15th May 2021.