Liu P, Wei X, Lin Z, Brochard G, Choi G J, Heidbrink W W, Nicolau J H, McKee G R
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
College of Engineering, University of Wisconsin, Madison, Wisconsin 53706, USA.
Phys Rev Lett. 2022 May 6;128(18):185001. doi: 10.1103/PhysRevLett.128.185001.
Global gyrokinetic simulations of mesoscale reversed shear Alfven eigenmodes (RSAE) excited by energetic particles (EP) in fusion plasmas find that RSAE amplitude and EP transport are much higher than experimental levels at nonlinear saturation, but quickly diminish to very low levels after the saturation if background microturbulence is artificially suppressed. In contrast, in simulations coupling micro-meso scales, the RSAE amplitude and EP transport decrease drastically at the initial saturation but later increases to the experimental levels in the quasisteady state with bursty dynamics due to regulation by thermal ion temperature gradient (ITG) microturbulence. The quasisteady state EP transport is larger for a stronger microturbulence. The RSAE amplitude in the quasisteady state ITG-RSAE turbulence from gyrokinetic simulations, for the first time, agrees very well with experimental measurements.
对聚变等离子体中由高能粒子（EP）激发的中尺度反向剪切阿尔文本征模（RSAE）进行的全球陀螺动力学模拟发现，在非线性饱和时，RSAE幅度和EP输运远高于实验水平，但如果人为抑制背景微湍流，饱和后它们会迅速降至非常低的水平。相比之下，在微观-中观尺度耦合模拟中，RSAE幅度和EP输运在初始饱和时急剧下降，但随后由于热离子温度梯度（ITG）微湍流的调节，在具有爆发性动力学的准稳态下增加到实验水平。对于更强的微湍流，准稳态EP输运更大。陀螺动力学模拟得到的准稳态ITG-RSAE湍流中的RSAE幅度首次与实验测量结果非常吻合。
