EAST自举电流条件下离散阿尔芬本征模
|
摘要
针对先进实验超导托卡马克(Experimental Advanced Superconducting Tokamak,EAST)装置,本文研究了自举电流和由气球模驱动势阱捕获的离散阿尔芬本征模(α-Induced Toroidal Alfvén Eigenmode,αTAE,α是等离子体压强梯度的标度)的联系;在自举电流条件下,高能量粒子激发αTAE为不稳定模式的情况.理论分析可得自举电流密度大的位置往往存在较大的等离子体压强梯度,而大的等离子体压强梯度很可能诱导产生αTAE.运用磁流体力学模型探讨了在自举电流条件下αTAE存在的特点,发现在小半径方向上自举电流密度较大的区间,集中存在αTAE;运用磁流体力学与回旋动理学混合模型探讨了αTAE被高能量粒子激发为不稳定模式的情况,发现在中性束注入加热等离子体和驱动等离子体电流条件下,当托卡马克中的高能量粒子和αTAE满足波粒共振条件时,αTAE都会被高能量粒子激发为不稳定模式.
Basing on experimental advanced superconducting Tokamak (EAST), we have researched relation between bootstrap current and α-induced toroidal Alfvén eigenmode (αTAE, α is a measure of plasma pressure gradient), which is investigated, in this paper, for the EAST tokamak operation condition with the bootstrap current. Our results show that the αTAE may exist in a relatively broad region of minor radius, where a large bootstrap current density is observed. In the presence of energetic particles, produced by the NBI experiments, our MHD-gyrokinetic hybrid simulations demonstrate that this quasi-marginally stable αTAE (within MHD description) can be readily destabilized by the kinetic compression upon the wave-particle resonances.
Basing on experimental advanced superconducting Tokamak (EAST), we have researched relation between bootstrap current and α-induced toroidal Alfvén eigenmode (αTAE, α is a measure of plasma pressure gradient), which is investigated, in this paper, for the EAST tokamak operation condition with the bootstrap current. Our results show that the αTAE may exist in a relatively broad region of minor radius, where a large bootstrap current density is observed. In the presence of energetic particles, produced by the NBI experiments, our MHD-gyrokinetic hybrid simulations demonstrate that this quasi-marginally stable αTAE (within MHD description) can be readily destabilized by the kinetic compression upon the wave-particle resonances.
引文
1 Alfvén H. Existence of electromagnetic-hydrodynamic waves. Nature, 1942, 150: 405–406
2 Evans T E, Valanju P M, Benesch J F, et al. Direct observation of the structure of global Alfvén eigenmodes in a tokamak plasma. Phys Rev Lett,1984, 53: 1743–1746
3 Cheng C Z, Chen L, Chance M S. High-n ideal and resistive shear Alfvén waves in tokamaks. Ann Phys, 1985, 161: 21–47
4 Chen L. Theory of magnetohydrodynamic instabilities excited by energetic particles in tokamaks. Phys Plasmas, 1994, 1: 1519–1522
5 Hu S, Chen L. Discrete Alfve?n eigenmodes in high-β toroidal plasmas. Phys Plasmas, 2004, 11: 1–4
6 Wang J, Hu S H, Dai Q P, et al. Discrete Alfvén eigenmodes in international thermonuclear experimental reactor operations with negative magneticshear. Chin Phys B, 2010, 19: 095202
7 Yao L B, Hu S H, Wang Y R, et al. Discrete Alfvén eigenmodes in present tokamaks (in Chinese). Nucl Fusion Plasma Phys, 2012, 32: 8–14 [姚龙宝, 胡双辉, 王一如, 等. 现行托卡马克参数下的离散阿尔芬本征模. 核聚变与等离子体物理, 2012, 32: 8–14]
8 Wang Y R, Hu S H, Yao L B, et al. Discrete Alfvén eigenmodes in high performance dischargesin the DⅢ-D tokamak (in Chinese). Nucl FusionPlasma Phys, 2012, 32: 140–147 [王一如, 胡双辉, 姚龙宝, 等. DⅢ-D高性能运行参数下的离散阿尔芬本征模. 核聚变与等离子体物理,2012, 32: 140–147]
9 Wang S, Long C Y, Hu S H, et al. Discrete Alfvén eigenmodes excited by energetic particles in JET (in Chinese). Nucl Fusion Plasma Phys,2013, 33: 304–311 [王帅, 龙超云, 胡双辉, 等. JET运行条件下高能量粒子激发的离散阿尔芬本征模. 核聚变与等离子体物理, 2013,33: 304–311]
10 Qin Z H, Hu S H. Kinetic analysis of discrete-Alfvén instability in tokamak (in Chinese). J Guizhao Univ (Nat Sci), 2015, 32: 18–22 [秦志豪,胡双辉. 托卡马克中离散阿尔芬不稳定性的动理学分析. 贵州大学学报(自然科学版), 2015, 32: 18–22]
11 Zheng Y H, Hu S H, Tian H N, et al. Alfvén instatabilities excited by energetic particles in the frequency range of Alfvén continuum (in Chinese).J Guizhao Univ (Nat Sci), 2015, 32: 23–27 [郑义鸿, 胡双辉, 田焕娜, 等, 连续谱频域中高能量粒子激发的阿尔芬不稳定性. 贵州大学学报(自然科学版), 2015, 32: 23–27]
12 Bickerton R J, Connor J W, Taylor J B. Diffusion driven plasma currents and bootstrap tokamak. Nat Phys Sci, 1971, 229: 110–112
13 Zarnstorff M C, Bell M G, Bitter M, et al. Bootstrap current in TFTR. Phys Rev Lett, 1988, 60: 1306–1309
14 Xu P, Zhang B C, Jia C Y, et al. Neutral beam injection heating experiments in the HT-6M device (in Chinese). Nucl Fusion Plasma Phys, 1991,11: 173–176 [须平, 张北超, 贾春雨, 等. HT-6M装置中性束注入加热初步实验. 核聚变与等离子体物理, 1991, 11: 173–176]
15 He H D, Dong J Q, Fu G Y, et al. Study of fishbone instabilities induced by energetic particles in tokamak plasmas. Nucl Fusion, 2011, 51:113012
16 Lee Y C, Van Dam J W, Drake J F, et al. Kinetic theory of ballooning instabilities and studies of tearing instabilities. In: Proceedings of 7thInternational Conference on Plasma Physics and controlled nuclear fusion. Innsbruck: International Atomic Agency, 1979
17 Connor J W, Hastie R J, Taylor J B. High mode number stability of an axisymmetric toroidal plasma. Proc R Soc A-Math Phys Eng Sci, 1979,365: 1–17
18 Connor J W, Hastie R J, Taylor J B. Shear, periodicity, and plasma ballooning modes. Phys Rev Lett, 1978, 40: 396–399
19 Chen L, Hasegawa A. Kinetic theory of geomagnetic pulsations: 1. Internal excitations by energetic particles. J Geophys Res, 1991, 96:1503–1512
20 Hu S, Chen L. Discrete Alfvén eigenmodes excited by energetic particles in high-β toroidal plasmas. Plasma Phys Control Fusion, 2005, 47:1251–1269
21 Li H, Wu B, Wang J, et al. Numerical simulation of non-inductive current driven scenario in EAST using neutral beam injection. Plasma SciTech, 2015, 17: 10–13
22 Gao X, Li G, Zhang T, et al. Long pulse H-mode scenarios sustained by RF heating on EAST. Plasma Sci Tech, 2015, 17: 448–453
23 Na Y S, Kessel C E, Park J M, et al. Simulations of KSTAR high performance steady state operation scenarios. Nucl Fusion, 2009, 49: 115018
24 Poli F M, Kessel C E, Bonoli P T, et al. Heating and current drive requirements towards steady state operation in ITER. AIP Conf Proc, 2014,1580: 33–40
2 Evans T E, Valanju P M, Benesch J F, et al. Direct observation of the structure of global Alfvén eigenmodes in a tokamak plasma. Phys Rev Lett,1984, 53: 1743–1746
3 Cheng C Z, Chen L, Chance M S. High-n ideal and resistive shear Alfvén waves in tokamaks. Ann Phys, 1985, 161: 21–47
4 Chen L. Theory of magnetohydrodynamic instabilities excited by energetic particles in tokamaks. Phys Plasmas, 1994, 1: 1519–1522
5 Hu S, Chen L. Discrete Alfve?n eigenmodes in high-β toroidal plasmas. Phys Plasmas, 2004, 11: 1–4
6 Wang J, Hu S H, Dai Q P, et al. Discrete Alfvén eigenmodes in international thermonuclear experimental reactor operations with negative magneticshear. Chin Phys B, 2010, 19: 095202
7 Yao L B, Hu S H, Wang Y R, et al. Discrete Alfvén eigenmodes in present tokamaks (in Chinese). Nucl Fusion Plasma Phys, 2012, 32: 8–14 [姚龙宝, 胡双辉, 王一如, 等. 现行托卡马克参数下的离散阿尔芬本征模. 核聚变与等离子体物理, 2012, 32: 8–14]
8 Wang Y R, Hu S H, Yao L B, et al. Discrete Alfvén eigenmodes in high performance dischargesin the DⅢ-D tokamak (in Chinese). Nucl FusionPlasma Phys, 2012, 32: 140–147 [王一如, 胡双辉, 姚龙宝, 等. DⅢ-D高性能运行参数下的离散阿尔芬本征模. 核聚变与等离子体物理,2012, 32: 140–147]
9 Wang S, Long C Y, Hu S H, et al. Discrete Alfvén eigenmodes excited by energetic particles in JET (in Chinese). Nucl Fusion Plasma Phys,2013, 33: 304–311 [王帅, 龙超云, 胡双辉, 等. JET运行条件下高能量粒子激发的离散阿尔芬本征模. 核聚变与等离子体物理, 2013,33: 304–311]
10 Qin Z H, Hu S H. Kinetic analysis of discrete-Alfvén instability in tokamak (in Chinese). J Guizhao Univ (Nat Sci), 2015, 32: 18–22 [秦志豪,胡双辉. 托卡马克中离散阿尔芬不稳定性的动理学分析. 贵州大学学报(自然科学版), 2015, 32: 18–22]
11 Zheng Y H, Hu S H, Tian H N, et al. Alfvén instatabilities excited by energetic particles in the frequency range of Alfvén continuum (in Chinese).J Guizhao Univ (Nat Sci), 2015, 32: 23–27 [郑义鸿, 胡双辉, 田焕娜, 等, 连续谱频域中高能量粒子激发的阿尔芬不稳定性. 贵州大学学报(自然科学版), 2015, 32: 23–27]
12 Bickerton R J, Connor J W, Taylor J B. Diffusion driven plasma currents and bootstrap tokamak. Nat Phys Sci, 1971, 229: 110–112
13 Zarnstorff M C, Bell M G, Bitter M, et al. Bootstrap current in TFTR. Phys Rev Lett, 1988, 60: 1306–1309
14 Xu P, Zhang B C, Jia C Y, et al. Neutral beam injection heating experiments in the HT-6M device (in Chinese). Nucl Fusion Plasma Phys, 1991,11: 173–176 [须平, 张北超, 贾春雨, 等. HT-6M装置中性束注入加热初步实验. 核聚变与等离子体物理, 1991, 11: 173–176]
15 He H D, Dong J Q, Fu G Y, et al. Study of fishbone instabilities induced by energetic particles in tokamak plasmas. Nucl Fusion, 2011, 51:113012
16 Lee Y C, Van Dam J W, Drake J F, et al. Kinetic theory of ballooning instabilities and studies of tearing instabilities. In: Proceedings of 7thInternational Conference on Plasma Physics and controlled nuclear fusion. Innsbruck: International Atomic Agency, 1979
17 Connor J W, Hastie R J, Taylor J B. High mode number stability of an axisymmetric toroidal plasma. Proc R Soc A-Math Phys Eng Sci, 1979,365: 1–17
18 Connor J W, Hastie R J, Taylor J B. Shear, periodicity, and plasma ballooning modes. Phys Rev Lett, 1978, 40: 396–399
19 Chen L, Hasegawa A. Kinetic theory of geomagnetic pulsations: 1. Internal excitations by energetic particles. J Geophys Res, 1991, 96:1503–1512
20 Hu S, Chen L. Discrete Alfvén eigenmodes excited by energetic particles in high-β toroidal plasmas. Plasma Phys Control Fusion, 2005, 47:1251–1269
21 Li H, Wu B, Wang J, et al. Numerical simulation of non-inductive current driven scenario in EAST using neutral beam injection. Plasma SciTech, 2015, 17: 10–13
22 Gao X, Li G, Zhang T, et al. Long pulse H-mode scenarios sustained by RF heating on EAST. Plasma Sci Tech, 2015, 17: 448–453
23 Na Y S, Kessel C E, Park J M, et al. Simulations of KSTAR high performance steady state operation scenarios. Nucl Fusion, 2009, 49: 115018
24 Poli F M, Kessel C E, Bonoli P T, et al. Heating and current drive requirements towards steady state operation in ITER. AIP Conf Proc, 2014,1580: 33–40