Study of the Current Circulation through the End Region of a Tandem Mirror and Its Suppression

串联镜端部环流及其抑制的研究

基本信息

批准号：
09680454
负责人：
SAITO Teruo
金额：
$ 2.24万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680454/
关键词：
Plasma Tandem Mirror End Plate Current Control Non ambipolar current ブラズマ

项目摘要

Electrically floating end plates are used for suppression of the non ambipolar diffusion stemming from the open filed configuration in a tandem mirror. However, experiments show that many issues are still open. 1. A residual non ambipolar diffusion remains. 2. Secondary electron emission due to ECRH - induced end loss electrons leads to a thermal loss to the end plates. 3. The mechanism of the three dimensional potential profile is not clear.Therefore, the present research has been carried out on the GAMMA 10 tandem mirror with two main objectives. 1. To Evaluate the non ambipolar current at the end plate from an integrated analysis of the current balance at the end plate. 2. To obtain a physical picture of the current circulation through the end plate and to reveal the current distribution through the plasma and the vacuum vessel.Main results of the present research are1. Necessity of a new current component at the end plate has been shown which compensates the current imbalance. This current amounts to a few tens of percent of the end loss electron current.2. Two ion current components have been discovered as counter parts of the new current. One is the ion current through the backside of the end plate ant the other originates from ionization neutral hydrogen atoms in the end region.3. A radial ion current has been observed during ECRH as a limiter current in the plug/barrier cell.4. A strong correlation has been shown between the radial ion current and the new current component at the end plate, which indicates a current circuit is formed between the plug/ barrier cell and the end plate. Furthermore, a current component has been observed in the radial ion current that likely originates in the central cell region.

电浮动端板用于抑制串联镜中开放场配置引起的非双极扩散。然而，实验表明许多问题仍然悬而未决。 1.残留的非双极扩散仍然存在。 2. 由于 ECRH 引起的端损电子导致二次电子发射，导致端板热损失。 3.三维电势分布的机理尚不清楚。因此，目前对GAMMA 10串列镜进行的研究有两个主要目标。 1. 通过端板电流平衡综合分析来评估端板非双极性电流。 2.获得流经端板的电流环流的物理图像，揭示流经等离子体和真空容器的电流分布。本研究的主要成果有： 1．已经证明在端板上需要一个新的电流元件来补偿电流不平衡。该电流相当于端损电子电流的百分之几十。2．已发现两个离子电流分量作为新电流的对应部分。一种是通过端板背面的离子电流，另一种源自端部区域电离中性氢原子。3．在 ECRH 期间观察到径向离子电流作为塞/势垒电池中的限制器电流。4。径向离子电流和端板处的新电流分量之间显示出很强的相关性，这表明在塞/阻挡单元和端板之间形成电流电路。此外，在可能起源于中心细胞区域的径向离子电流中观察到电流分量。