Investigation of the effectiveness of non-inductive `multi-harmonic' electron cyclotron current drive through modeling multi-pass absorptions in the EXL-50 spherical tokamak
D. Banerjee, S. D. Song, H. S. Xie, B. Liu, M. Y. Wang, W. J. Liu, B. Chen, L. Han, D. Luo, Y. Y. Song, Yu. V. Petrov, X. M. Song, M. S. Liu, R. W. Harvey, Y. J… 展开作者
D. Banerjee, S. D. Song, H. S. Xie, B. Liu, M. Y. Wang, W. J. Liu, B. Chen, L. Han, D. Luo, Y. Y. Song, Yu. V. Petrov, X. M. Song, M. S. Liu, R. W. Harvey, Y. J. Shi, Y. K. M. Peng, the EXL50 team
备注：
22 pages, 15 figures. Submitted to the Nuclear Fusion journal
The effectiveness of multiple electron cyclotron resonance (ECR) harmonics has been thoroughly investigated in context of high current drive efficiency, generally observed in fully non-inductive operation of the low aspect ratio EXL-50 spherical tokamak (ST) powered by electron cyclotron (EC) waves. The Fokker-Plank equation is numerically solved to obtain electron distribution function, under steady state of the relativistic nonlinear Coulomb collision and quasi-linear diffusion operators, for calculating plasma current driven by the injected EC wave. For the extra-ordinary EC wave, simulation results unfold a mechanism by which electrons moving around the cold second harmonic ECR layer strongly resonate with higher harmonics via the relativistic Doppler shifted resonance condition. This feature is in fact evident above a certain value of input EC wave power in simulation, indicating it to be a non-linear phenomenon. Similar to the experimental observation, high efficiency in current drive (over 1 A/W) has indeed been found in simulation for a typical low density ($\sim 1\times10^{18}~m^{-3}$), low temperature ($\lesssim 100$ eV) plasma of EXL-50 by taking into account multi-pass absorptions in our simulation model. However, such characteristic is not found in the ordinary EC-wave study for both single-pass and multi-pass simulations, suggesting it as inefficient in driving current on our ST device.
A Doppler backscattering diagnostic for the EXL-50U spherical tokamak: plasma considerations and preliminary quasioptical design
A*STAR Research Entities（新加坡科学研究局）；Imperial College London（帝国理工学院）；Nanyang Technological University（南洋理工大学）；UCLA（加州大学洛杉矶分校）；ENN Science & Technology Development Co., Ltd（新奥科技发展有限公司）
Non-Inductive Current Start-Up Using Multi-Harmonic Electron Cyclotron Wave and Current Ramp-Up Through Combined Electron Cyclotron Wave and Ohmic Heating in EXL-50U Spherical Torus
East China University of Science and Technology（华东理工大学）；Hebei Key Laboratory of Compact Fusion（河北省紧凑型聚变重点实验室）；ENN Science and Technology Development Co., Ltd.（新奥科技发展有限公司）；DISAT, Polytechnic University of Turin（都灵理工大学DISAT学院）；School of Nuclear Science and Technology, University of South China（南华大学核科学技术学院）；School of Resource Environment and Safety Engineering, University of South China（南华大学资源环境与安全工程学院）；North China Institute of Aerospace Engineering（北华航天工业学院）；Southwestern Institute of Physics（西南物理研究院）；Forschungszentrum Jülich GmbH, Institute of Fusion Energy and Nuclear Waste Management - Plasmaphysik（于利希研究中心有限公司聚变能与核废料管理研究所-等离子体物理）
Reinforcement learning for vertical position control on the EXL-50U spherical tokamak
Beijing ENN Fusion Energy Science and Technology Co., Ltd.（北京恩诺聚变能源科技有限公司）；Beijing Key Laboratory of High Magnetic Field Spherical Torus Fusion Energy（北京市高磁场球形托卡马克聚变能重点实验室）；Hebei Key Laboratory of Compact Fusion（河北省紧凑型聚变重点实验室）；School of Nuclear Science and Engineering, East China University of Technology（华东理工大学核科学与技术学院）；Institute of Robotics and Automatic Information System, Nankai University（南开大学机器人与自动化信息系统研究所）；Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics, Dalian University of Technology（大连理工大学物理学院教育部 beam 材料改性重点实验室）；Dalian University of Technology（大连理工大学）
Observer-Based Model Predictive Control for Isoflux Regulation in the EXL-50U Spherical Tokamak
Institute of Robotics and Automatic Information System, Nankai University（南开大学机器人与自动化信息研究所）；Beijing ENN Fusion Energy Science and Technology Co., Ltd.（北京新奥聚变能源科技有限公司）
A Novel Numerical Algorithms Optimization Method with Machine Learning Frameworks: Application on Real-time Plasmas Equilibrium Reconstruction in EXL-50U Spherical Torus
Nankai University（南开大学）；ENN Science and Technology Development Co., Ltd.（新奥科技发展有限公司）；Southwestern Institute of Physics（西南物理研究院）
AI Surrogate Modeling for Real-Time Tokamak Equilibrium Prediction: Benchmarking Neural Architectures and Validation on EXL-50U
Beijing ENN Fusion Energy Science and Technology Co., Ltd.（北京新奥聚变能源科技有限公司）；Xi’an University of Science and Technology（西安科技大学）；Xi’an Jiaotong University（西安交通大学）；Nankai University（南开大学）
Achievement of 1 MA Discharges in Hydrogen-Boron Plasmas on EXL-50U
Hebei Key Laboratory of Compact Fusion（河北紧凑型聚变重点实验室）；ENN Science and Technology Development Co., Ltd.（新奥科技发展有限公司）；Hefei University of Technology（合肥工业大学）；Southwestern Institute of Physics（西南物理研究院）；Forschungszentrum Jülich GmbH, Institute of Fusion Energy and Nuclear Waste Management- Plasmaphysik（于利希研究中心核能与核废物管理研究所等离子体物理部）
Non-thermal electron cyclotron emission during runaway plateau in tokamak disruptions from a highly anisotropic dielectric tensor
Seoul National University（首尔大学）；Nuclear Research Institute for Future Technology and Policy, Seoul National University（首尔大学未来技术与政策核研究所）；POSTECH（浦项工科大学）
Gyrotropy-Induced Symmetry Breaking of Erosion Hot Spots on Antenna Limiters during High-Power Tokamak RF Operation: Mechanisms and Mitigation Strategies
Mechanism of Ionization Avalanche in Tokamak Microwave Gas Breakdown
Seoul National University（首尔大学）；Nuclear Research Institute for Future Technology and Policy, Seoul National University（首尔大学未来技术与政策核研究所）；Korea Institute of Fusion Energy（韩国聚变能源研究所）；United Kingdom Atomic Energy Authority（英国原子能管理局）；General Atomics（通用原子公司）
Parametric instabilities of the inhomogeneous near SOL tokamak plasma, driven by the coupled effect of the high harmonic fast wave and of the ion and electron temperatures gradients, and anomalous heating of the near SOL ions
Plasma Research Center, Pusan National University（釜山国立大学等离子体研究中心）；Department of Electrical Engineering, Pusan National University（釜山国立大学电气工程系）
Oblique electron-cyclotron-emission radial and phase detector of rotating magnetic islands applied to alignment and modulation of electron-cyclotron-current-drive for neoclassical tearing mode stabilization
Advantage-level Aggregation Reinforcement Learning for X-point Target Magnetic Configuration Control in an EXL-50U Experiment-Calibrated Simulation Environment
Beijing ENN Fusion Energy Science and Technology Co., Ltd.（北京新奥融合能源科技有限公司）；Beijing Key Laboratory of High Magnetic Field Spherical Torus Fusion Energy（北京强磁场球形托卡马克聚变能源重点实验室）；Hebei Key Laboratory of Compact Fusion（河北省紧凑型聚变重点实验室）；Dalian University of Technology（大连理工大学）；School of Physics, Dalian University of Technology（大连理工大学物理学院）；Key Laboratory of Materials Modification by Beams of the Ministry of Education（教育部材料表面与界面工程重点实验室）；School of Nuclear Science and Engineering, East China University of Technology（东华理工大学核科学与工程学院）；East China University of Technology（东华理工大学）；School of Mechanics and Engineering Science, Peking University（北京大学力学与工程科学学院）；Peking University（北京大学）
Analytic stability boundaries for compressional and global Alfvén eigenmodes driven by fast ions. I. Interaction via ordinary and anomalous cyclotron resonances
A Rapid Integrated Tokamak Modelling Approach for Coupled Profile and Equilibrium Evolution
Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics, Dalian University of Technology（大连理工大学物理学院材料束改性教育部重点实验室）；Beijing VeloAlpha Technology Co., Ltd.（北京维洛阿尔法科技有限公司）
Non-modal kinetic theory of the stability of the compressed-sheared plasma flows generated by the inhomogeneous microscale turbulence in the tokamak edge plasma
Hollow toroidal rotation profiles in strongly electron heated H-mode plasmas in the ASDEX Upgrade tokamak
Max Planck Institute for Plasma Physics（马克斯·普朗克等离子体物理研究所）；Department of Applied Physics and Applied Mathematics, Columbia University（哥伦比亚大学应用物理与应用数学系）；VTT（芬兰技术研究中心VTT）
Role of kinetic instability in runaway electron avalanche and elevated critical electric fields
研究了动力学哨声波不稳定性对逃逸电子雪崩的影响。从DIII-D实验的参数，我们表明，稀土散射激发哨声波可以解释几个不太了解的实验结果中看到的各种托卡马克。我们发现雪崩增长率和阈值电场的增加，使本模型更接近观察比以前的结果。动力学不稳定性的激发和共振电子的散射计算自洽使用准线性模型。我们还解释了在DIII-D静态RE实验中观察到的电子回旋发射（ECE）信号的快速增长和极低频哨声模的激发[D. A. Spong等人，提交至Phys. Rev. Lett.]。这些结果表明，通过控制背景热等离子体温度，可以在托卡马克破裂中自发激发等离子体波，并抑制逃逸电子的雪崩产生。
