Research of Disruptive Instability based on Anomalous Transport

基于反常输运的破坏性不稳定性研究

• 批准号: 07680545
• 负责人: ITOH Kimitaka
• 金额: $ 1.47万
• 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 Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07680545/
• 关键词: disruptive instability; anomalous transport; strong turbulence; current diffusivity; transition of turbulence; magnetic trigger; pressure gradient; toroidal plasmas; ディスラプティブ不安定性; 異常輸送; 強い乱流; 電流拡散係数; 乱流遷移; 磁気トリガー; 圧力勾配; トロイダルプラズマ; toroidal

The object of this research project is to study the physics mechanisms for the abrupt growth of the plasma deformation (trigger phenomena), which plays the central role in the disruption events, and the rapid evolution of plasma profiles.In this course of research, it is theoretically predicted that there is a turbulence-turbulence transition. It is shown that the abrupt start of growth of the perturbation is possible to occur owing to the transition of turbulence. The sudden change of the growth rate at the onset of the collapse is the direct cause of the collapse events.The details of theoretical finding is as follows. The growth rate of the perturbation is not a smooth function of the plasma parameters, which are driving force of the instabilities. In contrast, the growth rate is subject to a bifurcation when the global driving force reaches a certain threshold value. The evolution of the perturbation turns to be explosive. Plasma deformation that leads to disruption is not a consequence of the linear instabilities, but behaves as a subcritical turbulence. The hysteresis relation between the driving force and the growth rate of perturbations is theoretically predicted.These theoretical view is examined by reviewing experimental observations. By surveying the observations on collapse events, it is found that the abrupt jump of the growth rate is commonly observed for almost all the disruptive phenomena. The new physics picture will be a basis of the future progress of the physics of disruptive phenomena.

该研究项目的目的是研究血浆变形突然生长（触发现象）的物理机制，该血浆变形（触发现象）在破坏事件中起着核心作用，以及血浆概况的快速演变。在这项研究过程中，理论上预测存在湍流扰动过渡。结果表明，由于湍流的过渡，可能会发生扰动的突然开始。崩溃开始时生长速率的突然变化是崩溃事件的直接原因。理论发现的细节如下。扰动的生长速率不是等离子体参数的平滑函数，而血浆参数是不稳定性的驱动力。相比之下，当全球驱动力达到一定的阈值时，增长率会受到分叉的约束。扰动的演变变成爆炸性。导致破坏的血浆变形不是线性不稳定性的结果，而是表现为亚临界湍流。从理论上预测了驱动力与扰动的增长率之间的滞后关系。通过审查实验观察，可以检查这些理论观点。通过调查对崩溃事件的观察结果，发现几乎所有破坏性现象通常都观察到生长速率的突然跳跃。新的物理图片将是破坏性现象物理学的未来进步的基础。

项目成果

K.Itoh, H.Sanuki: "Effect of radial electric field (in Japanese)" J.Plasma and Fusion Research. Vol.73, No.5 (in press). (1998)

K.Itoh、H.Sanuki：“径向电场的效应（日语）”J.Plasma and Fusion Research。

K.Itoh: "Current-diffusive interchange mode turbulence (in Japanese)" J.Plasma and Fusion Research. Vol.73, No.5 (in press). (1996)

K.Itoh：“电流扩散交换模式湍流（日语）”J.Plasma and Fusion Research。

K.Itoh, S.-I.Itoh and A.Fukuyama: "A Sawtooth Model based on the Transport Catastrophe" Plasma Phys. Control. Fusion. Vol.37, No.11. 1287-1297 (1995)

K.Itoh、S.-I.Itoh 和 A.Fukuyama：“基于传输灾难的锯齿模型”等离子体物理。

A.Fujisawa, ..., K.ITOH, et al.: "Dynamic Behavior of potential in the plasma core of the CHS Heliotron/torsatron" Phys.Rev.Lett.79. 1054-1057 (1997)

A.Fujisawa, ..., K.ITOH 等人：“CHS Heliotron/torsatron 等离子体核心电势的动态行为”Phys.Rev.Lett.79。

K.Itoh and S.-I.Itoh: "The Role of the Electric field in Confinement" Plasma Phys. Control. Fusion. Vol.38, No.1. 1-49 (1996)

K.Itoh 和 S.-I.Itoh：“电场在约束中的作用”等离子体物理学。