Study Of Edge Magnetic Topology And Heat Transport Changed By Resonant Magnetic Perturbation On EAST

During the tokamak experiments,edge localized mode is a kind of magnetohydrodynamic instability in H-mode discharges.Resonant magnetic perturbation(RMP)is a effective method to the control of edge localized mode ? The control mechanism is still unclear ? The change of magnetic topology induced by RMP is consider a essential factor.Based on EAST tokamak,three dimensional pattern of particle flux and enhancement of electron heat transport confirm the change of magnetic topology during ELM control experiments,which will contribute to further understanding of ELM control mechanism.The influence of mixed toroidal harmonic on divertor particle flux have validated the change of edge magnetic topology and particle flux could be dynamically controlled by rotating n=2harmonic,which are consistent with simulation results.Strike point splitting and three dimensional pattern of particle flux are observed.By rotating n=2 component of perturbation field,particle flux at additional strike point could be dynamically controlled.Comparing the simulation results of magnetic footprint by TOP2 D code and the ion saturation current pattern on divertor,a consistence between them is obtained.When ELM are not totally suppressed,particle flux pulses due to ELM will also show strike point splitting,which means the mode structure of ELM could be coupled tothree dimensional magnetic topology induced by resonant magnetic perturbation.Investigation of electron heat transport using the electron temperature perturbation induced by ELM burst for the first time indicates that electron heat transport is enhanced at edge region in the cases ELM mitigation effects has been achieved during the RMP control ELM experiments on EAST.The radial propagation of electron temperature perturbations with or without RMP is nearly the same and propagation process is not a typical heat transport process,which means this process may is mainly affected by ELM itself.Through simplifying and solving the electron heat balance equation,local electron temperature recovery process is analyzed and recovery characteristic time could be obtained as transport characteristic time.During the application of RMP,observation of faster recovery of electron temperature indicates that electron heat transport is enhanced at edge region.With the increase of radial position,the electron heat transport enhancement factor becomes larger,which could run up to 3 at edge of plasma.Change of edge topology is confirmed by three dimensional pattern of particle flux and enhancement of electron heat transport,which will helpful for further study of edge localized mode control mechanism and.expands the potential method to control the power load on target.