Simulation of microtearing turbulence in national spherical torus experimenta)
Simulation of microtearing turbulence in national spherical torus experimenta)
复制标题
国家球环面实验中微撕裂湍流模拟a)
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
H. Yuh
中科院分区：
文献类型：
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作者：
W. Guttenfelder;J. Candy;S. Kaye;W. Nevins;E. Wang;J. Zhang;R. Bell;N. Crocker;G. Hammett;B. LeBlanc;D. Mikkelsen;Y. Ren;H. Yuh
国家球形环面实验 (NSTX) 无量纲参数扫描中的热能限制时间随着碰撞性的降低而增加。虽然离子热传输是新经典的，但这些放电中反常电子热传输的来源仍不清楚，这导致在推断未来碰撞性低得多的球形托卡马克（ST）装置时存在相当大的不确定性。线性回旋运动模拟发现微撕裂模式在高碰撞放电中不稳定。 NSTX 中微撕裂湍流的首次非线性回旋运动模拟表明，它们可以产生实验水平的传输。磁颤动负责几乎所有的输运（∼98%），扰动场线轨迹是全局随机的，并且测试粒子随机输运模型与模拟输运的误差在 25% 以内。最重要的是，预计微撕裂传输会随着电子碰撞而增加，这与观察到的 NSTX 限制尺度一致......
Thermal energy confinement times in National Spherical Torus Experiment (NSTX) dimensionless parameter scans increase with decreasing collisionality. While ion thermal transport is neoclassical, the source of anomalous electron thermal transport in these discharges remains unclear, leading to considerable uncertainty when extrapolating to future spherical tokamak (ST) devices at much lower collisionality. Linear gyrokinetic simulations find microtearing modes to be unstable in high collisionality discharges. First non-linear gyrokinetic simulations of microtearing turbulence in NSTX show they can yield experimental levels of transport. Magnetic flutter is responsible for almost all the transport (∼98%), perturbed field line trajectories are globally stochastic, and a test particle stochastic transport model agrees to within 25% of the simulated transport. Most significantly, microtearing transport is predicted to increase with electron collisionality, consistent with the observed NSTX confinement scaling....