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Nuclear Fusion and Plasma Physics ›› 2025, Vol. 45 ›› Issue (1): 69-75.DOI: 10.16568/j.0254-6086.202501012

• Plasma Physics • Previous Articles     Next Articles

Effect of EAST density pedestal on linear peeling-ballooning mode stability

LIU Zhi-yang1, 2, WANG Yi-feng1, LI Yong-liang1, ZHANG Tao1, WANG Min-rui1, 2, ZANG Qing1, 2, LIU Hai-qing1, 2, XU Guo-sheng1, 2   

  1. (1. Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031; 2. University of Science and Technology of China, Hefei 230026)
  • Received:2023-01-16 Revised:2024-04-17 Online:2025-03-15 Published:2025-03-15

EAST密度台基对线性剥离气球模稳定性的影响

刘志洋1, 2,王一丰1,李永亮1,张  涛1,王敏锐1, 2,臧  庆1, 2,刘海庆1, 2,徐国盛*1, 2   

  1. (1. 中国科学院合肥物质科学研究院等离子体物理研究所,合肥 230031;2. 中国科学技术大学,合肥 230026)
  • 通讯作者: 徐国盛(1977-),男,安徽合肥人,研究员,博士研究生导师,从事核聚变等离子体诊断和边界台基物理研究。
  • 作者简介:刘志洋(1997-),男,湖北黄冈人,硕士研究生,从事核聚变等离子体边界台基物理研究。
  • 基金资助:
    国家磁约束核聚变能发展研究专项(2019YFE03030000,2022YFE03020004);国家自然科学基金青年科学基金(12005263)

Abstract:

To understand the effects of parameters related to the pedestal density profile (separatrix density, pedestal top density and normalized pedestal top collisionality) on the stability of linear peeling-ballooning mode in the pedestal, the simulations have been performed with the ELITE code based on the EAST experimental data. The results show that with the decrease of separatrix density(the pedestal temperature profile is kept invariant), the pedestal gradually moves from near the ballooning mode boundary dominated by high-n mode to near the peeling mode boundary dominated by low-n mode, this is mainly because the decrease of the separatrix density, increases the pressure gradient, and the ion diamagnetic frequency, resulting in a more stable high-n ballooning mode.As the pedestal top density decreases(the pedestal temperature profile remains invariant), the pedestal moves from the unstable region of the peeling-ballooning mode to the stable one. The normalized pedestal top collisionality was adjusted by changing the density and temperature. Its decrease causes the pedestal moving from the stable region of the peeling-ballooning mode to the unstable one.

Key words: Peeling-ballooning mode, Separatrix density, Pedestal top density, Normalized pedestal top collisionality

摘要:

为了理解台基密度分布相关参数(分界面密度、台基顶部密度和归一化台基顶部碰撞率)对台基区线性剥离气球模稳定性的影响,基于EAST实验数据并利用ELITE程序进行了模拟研究。研究表明,随着分界面密度的降低(保持台基温度分布不变),台基从高环向模数主导的气球模边界附近逐渐移动到较低环向模数主导的剥离模边界附近,这主要是因为分界面密度降低,使压强梯度增加,离子逆磁频率增加,导致高环向模数的气球模更加稳定;随着台基顶部密度的降低(保持台基温度分布不变),台基从剥离气球模不稳定区域移动到稳定区;通过改变密度、温度来改变归一化台基顶部碰撞率,随着归一化台基顶部碰撞率的降低,台基从剥离气球模稳定区域移动到不稳定区。

关键词: 剥离气球模, 分界面密度, 台基顶部密度, 归一化台基顶部碰撞率

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