A team of engineers and scientists at the UK Atomic Energy Authority has made a significant advancement in fusion energy research, potentially paving the way for a future of limitless energy. In a groundbreaking experiment, the team successfully stabilized plasma within a spherical tokamak, utilizing a novel approach with 3D magnetic coils.
This innovative technique addresses one of the critical challenges in achieving practical nuclear fusion: maintaining plasma stability. Nuclear fusion is the process that powers the sun, wherein two atomic nuclei combine to form a heavier nucleus, releasing vast amounts of energy. A tokamak employs powerful magnets to control the high-temperature plasma essential for this reaction.
The current leading spherical tokamak, known as MAST Upgrade, was commissioned by UKAEA in collaboration with the European Atomic Energy Community, and it began operations in 2020 at the Culham Centre for Fusion Energy in Oxfordshire. To facilitate fusion, scientists heat fusion fuel to extreme temperatures, creating plasma that enables the fusion process.
However, maintaining this plasma can be problematic. Elevated pressure, density, or current can lead to instability, which may harm the tokamak”s components and diminish its performance. In a recent press release, the UKAEA team detailed their use of Resonant Magnetic Perturbation (RMP) coils to effectively suppress Edge Localized Modes (ELMs). ELMs are instabilities that arise at the plasma”s edge and can pose significant risks to nuclear fusion apparatus.
The RMP coils create a small 3D magnetic field at the edge of the plasma, marking the first observation of ELM suppression in a spherical tokamak. James Harrison, Head of MAST Upgrade Science at UKAEA, remarked on the importance of this achievement, stating, “Suppressing ELMs in a spherical tokamak is a landmark achievement. It is an important demonstration that advanced control techniques developed for conventional tokamaks can be successfully adapted to compact configurations to develop the scientific basis for future power plants like STEP, the Spherical Tokamak for Energy Production.”
The recent experiment was a part of MAST Upgrade”s fourth scientific campaign, which concentrated on exploring plasma properties and managing plasma exhaust. The findings from this work are anticipated to play a crucial role in addressing the issue of ELMs and enhancing the potential of nuclear fusion as a reliable energy source. Additionally, this research will directly influence the development of ELM control systems for the UK”s Spherical Tokamak for Energy Production (STEP) program, which aims to generate net electricity from fusion by 2040. This initiative is central to a substantial investment by the UK government aimed at making fusion energy a viable reality.
