New Insights into Plasma Behavior in MAST Upgrade's Divertor

Recent research on the MAST Upgrade tokamak has provided new insights into the behavior of plasma in a strongly baffled divertor. The study, titled "Evolution of radiation profiles in a strongly baffled divertor on MAST Upgrade," was conducted by Fabio Federici and a team of 13 authors. It focuses on the interactions between plasma, impurities, and neutral particles, which are critical for understanding plasma detachment—a process that leads to significant losses of plasma power, momentum, and particles.

The research utilized a newly validated diagnostic tool, the InfraRed Video Bolometer (IRVB), which offers higher spatial resolution for mapping plasma emissivity compared to traditional methods. This capability is essential for assessing the relationship between particle flux and radiative detachment in the divertor and X-point regions.

Key findings from the study indicate that during the third MAST-U experimental campaign, the radiation peak shifted upstream from the target at lower upstream densities than previously expected. The inner leg of the divertor consistently detached before the outer leg, which aligns with earlier observations. The study also revealed that the energy confinement is related to detachment, with a notable margin between the radiation on the inner leg reaching the X-point and the confinement being affected. This characteristic could be advantageous for future reactor designs.

The implications of these findings are significant for the development of fusion energy. Understanding the dynamics of plasma detachment can lead to improved designs for future reactors, potentially enhancing their efficiency and stability. The full study can be accessed at arXiv:2409.02837.