The Study Of Three-dimensional Topology Physics Induced By Magnetic Perturbations In Tokamaks

This dissertation focuses on the three dimensional magnetic topology change in-duced by the actively applied non-axisymmetric resonant magnetic perturbations(RMPs)and the resulted 3D divertor power load distribution as well as 3D edge plasma trans-port.The divertor power load control is one of the main concerns of tokamaks ap-proaching long pulse and high confinement regime and future reactors.Edge localized mode(ELM)can be controlled by RMPs so the transient divertor power load can be removed.However the physical mechanism of the ELM-control is still unclear.The feasibility of using a dynamic RMP to control the steady state divertor power load in ELM-free H-mode is still under investigation.By comparing simulation results by the TOP2D code with the experimental observations,it is revealed that the plasma response plays a key role in determine the magnetic topology.The the 3D edge transport and the divertor power load can also be changed.The effectiveness of using a dynamical RMP field to control the divertor 3D power load is also confirmed by various experiments.By developing the field line tracing code TOP2D and taking into account the magnetic field from the plasma response calculated by magnetohydrodynamics code MARS-F,the magnetic topology can be modeled either in vacuum field assumption or in plasma response model.The modeling results show that the plasma response will influence the magnetic topology.The screening or amplifying effect of the plasma re-sponse will also weaken or enhance 3D magnetic topology change predicted by the the vacuum assumption.The field line penetration depth in the divertor magnetic footprint is then changed.The modeling results on D?-D show that the plasma response will also change the strike line splitting shape.In experiments,the 3D magnetic topology observation is mainly based on diagnostics measuring the 3D divertor heat and particle fluxes.These conclusions are also confirmed in EAST and D?-D experiments.The effectiveness of dynamic RMPs on steady state power load control is validated by experiments in EAST and D?-D.RMP schemes such as rigid rotating,spectrum scanning mixed toroidal harmonics are operated.The temporal evolution of divertor particle and heat flux profiles are changed along with the dynamic RMPs,while the ELM-control effect is not changed by the toroidally rotating harmonics.The RMP field applied on D?-D is a combination of the static n = 3 and rotating n=2 harmonics.The current change required in each coil is reduced,which will reduce the total energy consumption and the mechanical damage to the RMP coils.The EMC3-EIRENE code is used for the 3D edge plasma transport simulation and extended from the vacuum field assumption to the plasma response model.It is proved that the 3D magnetic topology will determine the 3D edge plasma transport charac-teristics.So the RMP resonance and the plasma response will influence the plasma transport in the edge.The comparisons between simulations and experiments indicate that the screening effect of the plasma response will reduce the width of edge stochas-tic layer,lead to the weakened plasma edge particle and energy transport,reduce the strike line splitting and weaken the ELM-control effect.A field line diffusion module,which bases on the simplified scrape-off layer transport model,is also developed in the TOP2D code.The heat flux distribution on divertor targets can be predicted much faster.The reliability of the field line diffusion code is confirmed by comparing with the EMC3-EIRENE simulation results.For the 3D physics research in EAST,this dissertation provides a simulation basis.The simulations can take into account plasma responses that calculated by MARS-F.The research on plasma response effects improves the understanding of ELM-control mechanism.The effectiveness of using dynamic RMPs to control the divertor power load is validated and related experiments provide more experimental data for extrapo-lating to future devices.