Figures-Observation of filament-like structures in ELMy H-mode plasma with a VUV imaging system developed on the EAST tokamak

Fig.1 shows an example of the SVD analysis performed on the raw VUV images taken during one ELM cycle with high framing rate.Ocilations are observed in Chronos during the inter-ELM phase, and filament-like structures appear on the Topos.Fig.2 Conditional average analysis shows the poloidal velocity of the filament-like structure is about 4.2 km/s.Fig.3 Auto-condition averages for different thresholds shos noe clear asymmetry due to the poor temporal resolution of the experimental data.Fig.4 Synthetic image can be produced by assuming plausible two-dimensional emission perturbation.

By comparing the synthetic images and experimental image, the mode structures can be derived.