Investigations on Confinement Improvement by Supressing Microscopic Instabilities in Toroidal Plasmas

通过抑制环形等离子体中微观不稳定性来改善约束的研究

• 批准号: 02808003
• 负责人: ITOH Kimitaka
• 金额: $ 1.41万
• 依托单位: National Institute for Fusion Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02808003/
• 关键词: Anomalous Transport; Toroidal Plasma; Microscopic Instability; Magnetiv Hill; Current Diffusivity; Disruptive Instability; 微視見不安定性; 磁場配位; ドリフト反転; スクレイプオフ層; 境界条件

The objective of this research is to develop the method to reduce the anomalous transport. Based on the working hypothesis that the cross field transport is driven by microscopic instabilities, we study the way to reduce the transport coefficient by suppressing the microinstabilities.By this research project, we have obtained a new theoretical result on the anomalous transport in Torsatron/Heliotron configurations. The theory includes the roles of the current diffusivity. This new model formula, though appricable only to the systems with the magnetic hill, explains the majority of the experimental observations on confinement in such devices. If further verification will be gained through future examination with experiments, this method will give a guiding principle to predict a cofiguration, in which anomalous transport is reduced. In tokamaks, it has been shown that the toroidicity is a critical element to cause the anomalous transport. The theoretical model can be extended to systems with the magnetic well, by employing the ballooning formalism. The extension and generalization are left for the future study.By studying the current diffusicity, we have obtained a new phsics picture of the disruptive phenomena. The mechanism of the accelerated growth of the global instabilities is presented. The magnetic braiding by the global instabilities gives rise to the enhanced current diffusivity, which then increases the growth rate of the mode.In summary, this research project has shown a considerable progress in the original programme as well as in the unexpected area of the research.

这项研究的目的是开发减少异常运输的方法。基于以下假设：跨场传输是由微观不稳定性驱动的，我们研究了通过抑制微型施加能力来降低运输系数的方法。通过该研究项目，我们已经获得了托托隆/螺旋体构型中异常运输的新理论结果。该理论包括当前扩散率的作用。这个新的模型公式虽然仅适用于带有磁性山的系统，但它解释了大多数有关此类设备限制的实验观察结果。如果将通过实验进行进一步的验证，则该方法将提供指导原则以预测合理化，其中降低了异常运输。在Tokamaks中，已经表明，环形性是引起异常运输的关键要素。理论模型可以通过采用气囊形式主义来扩展到具有磁孔的系统。扩展和概括是未来的研究。通过研究当前的扩散性，我们获得了破坏性现象的新phsics图片。提出了全球不稳定性加速增长的机制。全球不稳定性的磁编织会导致当前的扩散率增强，从而提高了模式的增长率。总而言之，该研究项目在原始程序以及研究的意外领域都取得了很大的进步。

项目成果

長崎 白伸: "Magnetic Field Stwcture near Plasma Boundary in Helical Systems and Diverfor Tokamaks" Japanese J.Apple Phys.29. 1336-1344 (1990)

Hakunobu Nagasaki：“螺旋系统和 Diverfor Tokamaks 中等离子体边界附近的磁场结构”Japan J.Apple Phys.29 (1990)。

A.J.Lichtenberg,K.Itoh,S.-I.Itoh and A.Fukuyama: "Role of Stochasticity in Sawtooth Oscillation" Nucl.Fusion. 32. (1992)

A.J.Lichtenberg、K.Itoh、S.-I.Itoh 和 A.Fukuyama：“随机性在锯齿振荡中的作用”Nucl.Fusion。

東井 和夫: "Role of Edge Magnetic Shear on the Limiter Hーmode Transition of the JlPP TーIIU Tokamak" Phys Rev.Lett.64. 1895-1898 (1990)

Kazuo Toi：“边缘磁剪切对 JlPP T-IIU 托卡马克限制器 H 模式转变的作用”Phys Rev.Lett.64 (1990)。

伊藤 早苗: "改善モ-ドとその閉じ込め改善度への評価" 核融合研究. 63. 356-379 (1990)

伊藤早苗：“约束力改善程度的改善模式及其评价” Fusion Research 63. 356-379 (1990)。

K. Itoh, H. Sanuki, J. Todoroki, T. Kamimura, S. -I. Itoh, A. Fukuyama and K. Hanatani: "Loss cone Region in Toroidal Helical Systems." Phys. Fluids B. 3. 1294-1296 (1991)

K. Itoh、H. Sanuki、J. Todoroki、T. Kamimura、S. -I。