Comparison of ELM-Filament Mitigation Between Supersonic Molecular Beam Injection and Pellet Injection on HL-2A

On HL-2A, two different injections (supersonic molecular beam injection (SMBI) and pellet injection (PI)) are used to mitigate edge localized mode (ELM)-filament convective transport. The changes of their characteristics are studied in this paper. A high spatiotemporal resolution probe shows there are many similar phenomena, and the filament density amplitude and radial velocity are both suppressed. Our statistical results indicate that: the velocity suppression comes from the decrease of filament density and temperature; the transient particle and heat fluxes drop strongly; and long-range correlation along a magnetic flux surface also decreases, when the electron-ion collisionality increases significantly, which may have a role on the filament parallel current during ELM mitigation.