JET D-T scenario with optimized non-thermal fusion

TLDR

JET deuterium‑tritium plasmas generate fusion power through thermonuclear reactions and fast‑particle interactions driven by neutral beam injection and ion‑cyclotron‑range‑of‑frequencies heating. The study aims to provide data for validating physics‑based models that predict D‑T fusion power. The experiment used a 15/85 D/T mixture with pure deuterium neutral beam injection combined with ion‑cyclotron resonance heating at the fundamental deuterium frequency. The non‑thermal scenario achieved a record 59 MJ of fusion energy in a single pulse, with 10.1 MW sustained over 5 s (Q = 0.33) and a peak of 12.5 MW over 2 s (Q = 0.38), confirming predictive models and demonstrating the highest fusion power achievable in JET with a Be/W wall.

Abstract

Abstract In JET deuterium-tritium (D-T) plasmas, the fusion power is produced through thermonuclear reactions and reactions between thermal ions and fast particles generated by neutral beam injection (NBI) heating or accelerated by electromagnetic wave heating in the ion cyclotron range of frequencies (ICRFs). To complement the experiments with 50/50 D/T mixtures maximizing thermonuclear reactivity, a scenario with dominant non-thermal reactivity has been developed and successfully demonstrated during the second JET deuterium-tritium campaign DTE2, as it was predicted to generate the highest fusion power in JET with a Be/W wall. It was performed in a 15/85 D/T mixture with pure D-NBI heating combined with ICRF heating at the fundamental deuterium resonance. In steady plasma conditions, a record 59 MJ of fusion energy has been achieved in a single pulse, of which 50.5 MJ were produced in a 5 s time window ( P fus = 10.1 MW) with average Q = 0.33, confirming predictive modelling in preparation of the experiment. The highest fusion power in these experiments, P fus = 12.5 MW with average Q = 0.38, was achieved over a shorter 2 s time window, with the period of sustainment limited by high-Z impurity accumulation. This scenario provides unique data for the validation of physics-based models used to predict D-T fusion power.