Impact of plasma core profiles on MHD stability at tokamak edge pedestal
Impact of plasma core profiles on MHD stability at tokamak edge pedestal
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DOI：
10.1088/0029-5515/54/11/114007
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发表时间：
2013-11
期刊：
影响因子：
3.3
通讯作者：
N. Aiba;H. Urano
中科院分区：
文献类型：
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作者：
N. Aiba;H. Urano
为了扩展小振幅草边局域模（ELM）的工作范围，数值研究了托卡马克边缘基座等离子体芯轮廓对磁流体动力学（MHD）稳定性的影响。在EPED 1模型可以预测基座压力分布和草ELM的触发是理想的气球模式的假设下，研究了等离子体极向β和等离子体内部电感对边缘MHD稳定性的影响，这些参数与等离子体芯部分布有关，是JET准双零等离子体中草ELMy H模的重要参数。数值结果表明，气球模式可以通过减少极向β和/或内部电感不稳定。与此相反，它被证实，基座密度，这也是一个重要的参数，实现草ELMy H模式，可以稳定的气球模式。结合这些趋势，可以通过仔细调整参数来放松草ELMy H模式的必要条件，尽管由于边缘电流密度的增加，这种放松更容易使I型ELM不稳定。
Impact of plasma core profiles on magnetohydrodynamics (MHD) stability at tokamak edge pedestal is investigated numerically to extend an operation regime for small amplitude grassy edge localized mode (ELM). With the hypotheses that pedestal pressure profile can be predicted with the EPED1 model and the trigger of grassy ELM is an ideal ballooning mode, the impacts of plasma poloidal beta and plasma internal inductance on edge MHD stability are investigated, the parameters of which are related to plasma core profiles and are important parameters for grassy ELMy H-modes in JET quasi-double null plasma. The numerical results indicate that a ballooning mode can be destabilized by decreasing poloidal beta and/or internal inductance. In contrast, it is confirmed that pedestal density, which is also an important parameter for realizing grassy ELMy H-mode, can stabilize a ballooning mode. In combination with these trends, it is possible to relax the necessary conditions for grassy ELMy H-mode by adjusting the parameters carefully, though this relaxation destabilizes type-I ELM more easily due to the increase in edge current density.