| The main goal of magnetic confinement fusion is to produce a high-pressure,steady-state plasma,so as to improve the economic benefits of future nuclear fusion applications.In the magnetic confinement fusion device,the external kink mode driven by plasma current or pressure is an important macro MHD instability,which is an obstacle for the achievement of higher pressure.Its characteristic time scale is in the order of microseconds.We defined the conductor wall with zero resistance as ideal wall and with finite resistance as resistive wall.The theoretical study shows that when the ideal wall around the plasma is close enough to the plasma,the external kink mode can be stabilized.In fact,there is no ideal wall.Under the condition of resistive wall,the external kink mode can not be completely stablized,and its residual unstable mode is called the resistive wall mode.Its characteristic time scale increases from microsecond to millisecond.The diffusion time of the magnetic disturbance through the resistance wall is defined as the characteristic time of the resistive wall mode.When the discharge time of advanced Tokamak(high-voltage,large bootstrap current,long pulse)is longer than the characteristic time of the resistive wall mode,the resistive wall mode will affect the stable operation of the Tokamak,and even cause the discharge termination.Therefore,it is necessary to control the resistive wall mode instability in long pulse steady-state discharge.There are three ways to control the resistive wall mode: the first one is passive control,which is to stabilize the resistive wall mode by plasma rotation and kinetic damping;the second one is active control,which is to stabilize the resistive wall mode by adding feedback coil to compensate the magnetic field;the last one is a combination of active and passive control.The main work of this thesis is as follows: 1.Based on the 9 MA equilibrium configuration of ITER,the resistive wall mode is controlled respectively by plasma rotation and coil feedback,and the control of resistive wall mode by the combination plasma rotation and feedback are studied by using MARS program;2.Based on the 2 MA equilibrium configuration of HL-2M,the influence of kinetic effect on the resistive wall mode stabilized by plasma rotation,the influence of feedback control combined with kinetic on the resistive wall mode,and the evolution of feedback control system at any time are studied by using MARS program.This thesis is divided into five chapters:In chapter 1,briefly introduces the research background,and the research and development of some magnetic confinement fusion devices and resistive wall models.In chapter 2,the development history of MARS program and its physical model are briefly introduced.In chapter 3,based on the 9 MA equilibrium configuration of ITER,the control of plasma rotation on the resistive wall mode is studied by using Mars program firstly;then,the active control of the middle group,the upper and lower groups and all three groups of coils to the resistive wall mold is studied by using the flux-current control method;finally,the combination of plasma rotation and feedback control on the resistive wall mode is studied.In chapter 4,based on the 2 MA equilibrium configuration of HL-2M,we introduce the effect of plasma rotation on the resistive wall mode in the dynamic model.It is found that the rotation frequency of the stable resistive wall mode can be reduced by adding the kinetic effect.Then,the synergy between feedback control and kinetic effect is studied by using flux-voltage feedback control.Finally,in the kinetic model,the evolution of the feedback system at any time and the relationship between the minimum voltage of the stable resistive wall mode and the plasma rotation frequency and the feedback gain amplitude are studied.The chapter 5 is the summary and discussion of the dissertation. |
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