Tracking blobs in the turbulent edge plasma of a tokamak fusion device

• Published in: Scientific reports 2022-10, Vol.12 (1), p.18142-18142, Article 18142
• Main Authors: Han, Woonghee, Pietersen, Randall A., Villamor-Lora, Rafael, Beveridge, Matthew, Offeddu, Nicola, Golfinopoulos, Theodore, Theiler, Christian, Terry, James L., Marmar, Earl S., Drori, Iddo
• Format: Article
• Language: English
• Subjects: 639/705/117; 639/766/1960/1136; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Computer science; Energy; Filaments; Heat; Humanities and Social Sciences; Magnetic fields; Magnetically confined plasmas; multidisciplinary; Plasma; Science; Science & Technology - Other Topics; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-21671-w

The analysis of turbulence in plasmas is fundamental in fusion research. Despite extensive progress in theoretical modeling in the past 15 years, we still lack a complete and consistent understanding of turbulence in magnetic confinement devices, such as tokamaks. Experimental studies are challenging due to the diverse processes that drive the high-speed dynamics of turbulent phenomena. This work presents a novel application of motion tracking to identify and track turbulent filaments in fusion plasmas, called blobs, in a high-frequency video obtained from Gas Puff Imaging diagnostics. We compare four baseline methods (RAFT, Mask R-CNN, GMA, and Flow Walk) trained on synthetic data and then test on synthetic and real-world data obtained from plasmas in the Tokamak à Configuration Variable (TCV). The blob regime identified from an analysis of blob trajectories agrees with state-of-the-art conditional averaging methods for each of the baseline methods employed, giving confidence in the accuracy of these techniques. By making a dataset and benchmark publicly available, we aim to lower the entry barrier to tokamak plasma research, thereby greatly broadening the community of scientists and engineers who might apply their talents to this endeavor.