Rotational shear effects on edge harmonic oscillations in DIII-D quiescent H-mode discharges
Rotational shear effects on edge harmonic oscillations in DIII-D quiescent H-mode discharges
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DOI：
10.1088/0029-5515/56/7/076011
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发表时间：
2015-11
期刊：
影响因子：
3.3
通讯作者：
Xi Chen;K. Burrell;N. Ferraro;T. Osborne;M. Austin;A. Garofalo;R. Groebner;G. Kramer;N. Luhmann;G. McKee;C. Muscatello;R. Nazikian;X. Ren;P. Snyder;W. Solomon;B. Tobias;Zheng Yan
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文献类型：
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作者：
Xi Chen;K. Burrell;N. Ferraro;T. Osborne;M. Austin;A. Garofalo;R. Groebner;G. Kramer;N. Luhmann;G. McKee;C. Muscatello;R. Nazikian;X. Ren;P. Snyder;W. Solomon;B. Tobias;Zheng Yan
在静态H模(QH模)区，边缘谐振荡(EHO)通过提供良性和连续的边缘粒子输运，在避免瞬时边缘局域模(ELM)功率流方面起着重要作用。对DiI-D QH模等离子体中低n(n⩽5)EHO进行了详细的理论、实验和模型比较。从扩展的磁流体力学(MHD)程序M3D-C1计算的线性本征模结构，与来自外部磁性数据和内部测量的相干EHO性质，以及理想的MHD代码精英所发现的扭结/剥离模式性质，以及使用欧洲经委会、北京谱仪、欧洲经委会成像和微波成像反射仪(MIR)的诊断结果非常接近。数值研究表明，M3D-C1的低n类EHO解因旋转和/或旋转剪切而失稳，而高n模则稳定。这一效应与旋转方向无关，这表明EHO原则上可以通过在任何一个方向上的旋转而不稳定。模拟结果与EHO的观测结果一致，支持了EHO是一种边缘E×B旋转剪切失稳的低n扭结/剥离模的理论，提高了我们对在现有和未来器件中产生和维持QH模的理解和信心。
In the quiescent H-mode (QH-mode) regime, edge harmonic oscillations (EHOs) play an important role in avoiding transient edge localized mode (ELM) power fluxes by providing benign and continuous edge particle transport. A detailed theoretical, experimental and modeling comparison has been made of low-n (n ⩽ 5) EHO in DIII-D QH-mode plasmas. The calculated linear eigenmode structure from the extended magentoohydrodynamics (MHD) code M3D-C1 matches closely the coherent EHO properties from external magnetics data and internal measurements using the ECE, BES, ECE-Imaging and microwave imaging reflectometer (MIR) diagnostics, as well as the kink/peeling mode properties found by the ideal MHD code ELITE. Numerical investigations indicate that the low-n EHO-like solutions from M3D-C1 are destabilized by rotation and/or rotational shear while high-n modes are stabilized. This effect is independent of the rotation direction, suggesting that EHOs can be destabilized in principle with rotation in either direction. The modeling results are consistent with observations of EHO, support the proposed theory of the EHO as a low-n kink/peeling mode destabilized by edge E × B rotational shear, and improve our understanding and confidence in creating and sustaining QH-mode in present and future devices.