Intermittent convective transport suppressed by supersonic molecular beam injection on the HL-2A tokamak

Edge localized mode (ELM)- filament statistical characteristics and intermittent convective transport are studied during ELM mitigation (10- 30 ms) induced by supersonic molecular beam injection (SMBI) on the HL- 2A tokamak. Langmuir probe data show that the burst rate of large amplitude filaments (dne > 4s) decreases by 30- 50% and their radial velocity decreases by 40- 60%, which is an indication of an (E) over right arrowx (B) over right arrow amplitude reduction. A decrease of long-range correlation along the magnetic flux surface is observed after SMBI, indicating a role of electron- ion collisionality on the filament parallel current in the ELM mitigation time. The transient particle and heat fluxes decrease about 40- 50% and 50- 60%, respectively. These observations indicate that SMBI might be an effective method to suppress the intermittent convective transport.