The research team includes Eric Emdee and collaborators from PPPL, MIT, and North Carolina State University, conducting experiments at the DIII-D facility and publishing in Physical Review Letters.

Key collaborators from PPPL, MIT, and North Carolina State University used the DIII-D National Fusion Facility, with support from the U.S. Department of Energy, to carry out the study featured in Physical Review Letters.

The findings show that parallel flow driven by rotating plasma core influences edge flows at the divertor, a factor that must be accounted for in predicting exhaust behavior and designing divertors for future fusion power plants.

When core rotation combines with cross-field drifts, the impact on recycling asymmetries is significantly greater than either factor alone, underscoring the need to include edge-flow dynamics driven by rotation in reactor design.

Accurately predicting exhaust impacts in fusion devices requires integrating core rotation effects into edge-flow models, potentially improving the durability and performance of future reactors.

The work is led by Eric Emdee with team members from PPPL, MIT, and NC State, and it was funded by the U.S. Department of Energy.

Using SOLPS-ITER simulations at Princeton Plasma Physics Laboratory, the team investigated why tokamak exhaust particles land asymmetrically, favoring the inner divertor target.

The Physical Review Letters study shows toroidal rotation, together with cross-field drifts, explains why more plasma hits the inner divertor target than the outer one, aligning simulations with experiments.

Earlier models that considered only cross-field drifts failed to reproduce the observed asymmetry, raising questions about the reliability of design guidance.

By including core rotation, the simulations resolved the discrepancy and improved the reliability of divertor design guidance.

Initial explanations based solely on cross-field drifts were insufficient for modeling the observed asymmetry, limiting their usefulness for divertor design.

The study appears in Physical Review Letters under the title Combined Influence of Rotation and Scrape-Off Layer Drifts on Recycling Asymmetries in Tokamak Plasmas, published in late 2025.