Simulation study on impacts of the parallel electron response and the Hall effect on edge localized mode for HL-3

In this paper, we first investigate impacts of the parallel electron response and the Hall effect on edge localized mode (ELM) crash using the BOUT++ three-field model for a 1 MA H-mode discharge on HL-3. A scan of edge safety factor q and magnetic shear s shows that the ratio HD of the Hall scaling factor to the dynamo scaling factor exceed 0.3, indicating the Hall effect at the pedestal cannot be neglected on HL-3. Simulations reveal that the Drift-Alfvén Wave (DAW) instability, driven by the parallel electron response, enhances the linear growth rate and hinders turbulence propagate to the inner of pedestal and the SOL, thereby reducing ELM size. Impacts of E_r shear on the DAW instability are studied by modulating shear flows. Both co-directional (while the shear flow is in the same direction of the ion diamagnetic drift) and counter-directional (while the shear flow is in the different direction of the ion diamagnetic drift) flows do not alter DAW destabilization but weaken its suppression of turbulence transport and reduce the inward shift of the crash location. Compared to counter-flow, the DAW instability can lead to premature termination of the ELM crash and the suppressive effect of DAW instability on the ELM crash is significantly reduced when considering co-flow.