Advances in physics understanding of high poloidal beta regime toward steady-state operation of CFETR
Advances in physics understanding of high poloidal beta regime toward steady-state operation of CFETR
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DOI：
10.1063/5.0032490
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发表时间：
2019-10
期刊：
影响因子：
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通讯作者：
J. Qian;A. Garofalo;X. Gong;J. Huang;S. Ding;C. Holcomb;A. Hyatt;J. Ferron;J. Mcclenaghan
中科院分区：
文献类型：
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作者：
J. Qian;A. Garofalo;X. Gong;J. Huang;S. Ding;C. Holcomb;A. Hyatt;J. Ferron;J. Mcclenaghan
在DIII-D和EAST托卡马克上进行的高βp情景的实验和建模研究表明，高βp情景具有高能量约束、避免n = 1 MHD和减少热流的核心边缘集成等优势，使其成为中国聚变工程试验堆稳态运行的一个有吸引力的选择。实验表明，在DIII-D上注入中性束（βp ~ 2.2, βN ~ 3.5, fBS ~ 50%, fGw ~ 1.0, H98y2 ~ 1.5），在EAST上注入纯射频功率（βp ~ 2.0, βN ~ 1.6, fBS ~ 50%, fGw ~ 0.8, H98y2 > 1.3），可以获得高约束和高密度的等离子体。通过调整电流密度分布图，可以实现具有局部（离轴）负剪切的q分布图，从而提高约束和MHD的稳定性。输运分析和模拟表明，高密度梯度和高沙弗拉诺夫位移的结合可以实现湍流稳定和更高的约束。采用轴向电子回旋加速器加热注入，避免了EAST上的钨积累，并在建模中得到了再现。通过对辐射导流器的主动反馈控制，可以降低热流密度（降低40%）并保持高堆芯约束，这是托卡马克长脉冲运行的重要结果。利用改进的物理理解和经过验证的建模工具，设计了1gw的CFETR稳态方案。
Experimental and modeling investigations of high βp scenarios on DIII-D and EAST tokamaks show advantages in high energy confinement, avoidance of n = 1 MHD, and core-edge integration with reduced heat flux, making this scenario an attractive option for China Fusion Engineering Test Reactor steady-state operation. Experiments show that plasmas with high confinement and high density can be achieved with neutral beam injection on DIII-D (βp ∼ 2.2, βN ∼ 3.5, fBS ∼ 50%, fGw ∼ 1.0, and H98y2 ∼ 1.5) and pure RF power on EAST (βP ∼ 2.0, βN ∼ 1.6, fBS ∼ 50%, fGw ∼ 0.8, and H98y2 > 1.3). By tailoring the current density profile, a q-profile with local (off-axis) negative shear is achieved, which yields improved confinement and MHD stability. Transport analysis and simulation suggest that the combination of a high density gradient and high Shafranov shift allows turbulence stabilization and higher confinement. Using on-axis Electron Cyclotron Heating injection, tungsten accumulation is avoided on EAST, and this is reproduced in modeling. Reduced heat flux (by > 40%) and maintenance of high core confinement is achieved with active feedback control of the radiated divertor, an important result for long pulse operation in tokamaks. The improved physics understanding and validated modeling tools are used to design a 1 GW steady-state scenario for CFETR.