Transport of fast ions is a crucial issue during the operation of ITER.Redistribution of neutral beam injection(NBI)fast ions by the ideal internal magnetohydrodynamic(MHD)instabilities in ITER is studied utilizing th...Transport of fast ions is a crucial issue during the operation of ITER.Redistribution of neutral beam injection(NBI)fast ions by the ideal internal magnetohydrodynamic(MHD)instabilities in ITER is studied utilizing the guiding-center code ORBIT(White R B and Chance M S 1984Phys.Fluids 272455).Effects of the perturbation amplitude A of the internal kink,the perturbation frequency f of the fishbone instability,and the toroidal mode number n of the internal kink are investigated,respectively,in this work.The n=1 internal kink mode can cause NBI fast ions transporting in real space from regions of 0<s≤0.32 to 0.32<s≤0.53,where s labels the normalized plasma radial coordinate.The transport of fast ions is greater as the perturbation amplitude increases.The maximum relative change of the number of fast ions approaches 5%when the perturbation amplitude rises to 500 G.A strong transport is generated between the regions of 0<s≤0.05 and 0.05<s≤0.12 in the presence of the fishbone instability.Higher frequency results in greater transport,and the number of fast ions in 0<s≤0.05 is reduced by 30%at the fishbone frequency of 100 k Hz.Perturbations with higher n will lead to the excursion of fast ion transport regions outward along the radial direction.The loss of fast ions,however,is not affected by the internal MHD perturbation.Strong transport from 0<s≤0.05 to 0.05<s≤0.12 does not influence the plasma heating power of ITER,since the NBI fast ions are still located in the plasma core.On the other hand,the influence of fast ion transport from 0<s≤0.32 to 0.32<s≤0.53 needs further study.展开更多
Based on the conventional tokamak HL-2 A-like parameters and profiles,the linear properties and the nonlinear dynamics of non-resonant kink mode(NRK)and non-resonant fishbone instability(NRFB)in reversed shear tokamak...Based on the conventional tokamak HL-2 A-like parameters and profiles,the linear properties and the nonlinear dynamics of non-resonant kink mode(NRK)and non-resonant fishbone instability(NRFB)in reversed shear tokamak plasmas are investigated by using the global hybrid kinetic-magnetohydrodynamic nonlinear code M3 D-K.This work mainly focuses on the effect of passing energetic-ions on the NRK and NRFB instabilities,which is different from the previous works.It is demonstrated that the NRFB can be destabilized by the passing energeticions when the energetic-ion betaβ;exceeds a critical value.The transition from NRK to NRFB occurs when the energetic-ion betaβ;increases to above a critical value.The resonance condition responsible for the excitation of NRFB is interestingly found to be satisfied atω;+ω;≈ω,whereω;is the toroidal motion frequency,ω;is the poloidal motion frequency andωis the mode frequency.The nonlinear evolutions of NRFB’s mode structures and Poincaréplots are also analyzed in this work and it is found that the NRFB can induce evident energeticion loss/redistribution,which can degrade the performance of the plasmas.These findings are conducive to understanding the mechanisms of NRFB induced energetic-ion loss/redistribution through nonlinear wave-particle interaction.展开更多
In the frame of weak nonlinear theory,a set of equations depicting the nonlinear interactions of barotropic Rossby waves are derived,the topography and Ekman fric-tion are involved in the equations.Starting from the e...In the frame of weak nonlinear theory,a set of equations depicting the nonlinear interactions of barotropic Rossby waves are derived,the topography and Ekman fric-tion are involved in the equations.Starting from the equations,we investigate the in -teraction of three Rossby wave packets with narrow-spread in wave vectors.When an intense primary pump Rossby wave with amplitude larger than a threshold propagates through the atmosphere ,the amplitude of one Rossby wave packet with scale greaterthan the primary one and one Rossby wave packet with scale smaller than the primaryone grow exponentially through three wave interactions,the intrinsic frequencies of the secondary waves can be varied,The threshold and the variation of the intrinsic frequ-encies of the secondary waves are related to the Ekman friction frequency dismatchtopography and spatial evolution of the secondary Rossby wave packets.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2022YFE03060002,2019YFE03090100)by the Innovation Program of Southwestern Institute of Physics(No.202001XWCXRC001)partly supported by the Youth Science and Technology Innovation Team of Sichuan Province(No.2022JDTD0003)。
文摘Transport of fast ions is a crucial issue during the operation of ITER.Redistribution of neutral beam injection(NBI)fast ions by the ideal internal magnetohydrodynamic(MHD)instabilities in ITER is studied utilizing the guiding-center code ORBIT(White R B and Chance M S 1984Phys.Fluids 272455).Effects of the perturbation amplitude A of the internal kink,the perturbation frequency f of the fishbone instability,and the toroidal mode number n of the internal kink are investigated,respectively,in this work.The n=1 internal kink mode can cause NBI fast ions transporting in real space from regions of 0<s≤0.32 to 0.32<s≤0.53,where s labels the normalized plasma radial coordinate.The transport of fast ions is greater as the perturbation amplitude increases.The maximum relative change of the number of fast ions approaches 5%when the perturbation amplitude rises to 500 G.A strong transport is generated between the regions of 0<s≤0.05 and 0.05<s≤0.12 in the presence of the fishbone instability.Higher frequency results in greater transport,and the number of fast ions in 0<s≤0.05 is reduced by 30%at the fishbone frequency of 100 k Hz.Perturbations with higher n will lead to the excursion of fast ion transport regions outward along the radial direction.The loss of fast ions,however,is not affected by the internal MHD perturbation.Strong transport from 0<s≤0.05 to 0.05<s≤0.12 does not influence the plasma heating power of ITER,since the NBI fast ions are still located in the plasma core.On the other hand,the influence of fast ion transport from 0<s≤0.32 to 0.32<s≤0.53 needs further study.
基金support of these experiments and the Supercomputer Center of Dalian University of Technology for providing computing resourcessupported by National Natural Science Foundation of China(Nos.11925501,11975068 and 11835010)+1 种基金China Postdoctoral Science Foundation(No.2021M700674)the Fundament Research Funds for the Central Universities(No.DUT21GJ205)。
文摘Based on the conventional tokamak HL-2 A-like parameters and profiles,the linear properties and the nonlinear dynamics of non-resonant kink mode(NRK)and non-resonant fishbone instability(NRFB)in reversed shear tokamak plasmas are investigated by using the global hybrid kinetic-magnetohydrodynamic nonlinear code M3 D-K.This work mainly focuses on the effect of passing energetic-ions on the NRK and NRFB instabilities,which is different from the previous works.It is demonstrated that the NRFB can be destabilized by the passing energeticions when the energetic-ion betaβ;exceeds a critical value.The transition from NRK to NRFB occurs when the energetic-ion betaβ;increases to above a critical value.The resonance condition responsible for the excitation of NRFB is interestingly found to be satisfied atω;+ω;≈ω,whereω;is the toroidal motion frequency,ω;is the poloidal motion frequency andωis the mode frequency.The nonlinear evolutions of NRFB’s mode structures and Poincaréplots are also analyzed in this work and it is found that the NRFB can induce evident energeticion loss/redistribution,which can degrade the performance of the plasmas.These findings are conducive to understanding the mechanisms of NRFB induced energetic-ion loss/redistribution through nonlinear wave-particle interaction.
文摘In the frame of weak nonlinear theory,a set of equations depicting the nonlinear interactions of barotropic Rossby waves are derived,the topography and Ekman fric-tion are involved in the equations.Starting from the equations,we investigate the in -teraction of three Rossby wave packets with narrow-spread in wave vectors.When an intense primary pump Rossby wave with amplitude larger than a threshold propagates through the atmosphere ,the amplitude of one Rossby wave packet with scale greaterthan the primary one and one Rossby wave packet with scale smaller than the primaryone grow exponentially through three wave interactions,the intrinsic frequencies of the secondary waves can be varied,The threshold and the variation of the intrinsic frequ-encies of the secondary waves are related to the Ekman friction frequency dismatchtopography and spatial evolution of the secondary Rossby wave packets.
