Study on RF Tandem Mirror

射频串联镜研究

• 批准号: 62420051
• 负责人: ITATANI Ryohei
• 金额: $ 11.78万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62420051/
• 关键词: Tandem Mirror; Ion Cyclotron Heating; Helicon Wave; Ion Hybrid Resonance; MHD Stability; Potential; Confinement; Thermal Barrier; タンデムミラー; MHD安定化; RF安定化

The main purpose of the RF tandem mirror project is to demonstrate plasma confinement in purely axisymmetric magnetic field configuration by using ICRF power only. We have revealed that the plasma production, MHD-stabilization, ion heating, and plug and thermal barrier potential formation can all be achieved by a combination of the central RF and the plug RF.The highest peak density produced by the helicon/fast wave excited by the central RF is 1.8X10^<13>cm^<-3> with the beta value of - 10 % for helium plasma. In a two-ion-species plasma, ion temperatures of Ti_1 - 220 eV have been achieved at densities of 0.4x10^<13>cm^<-3>. This heating is due to the mode conversion of the helicon/fast wave into the slow Alfven wave at the hybrid resonance. The plasma is MHD-stable due to the RF ponderomotive effect. The central RF produces the potential dip at the plug midplane. This dip is formed by the sloshing ion distribution created by the minority ion heating in the plug cell. The plug potential phi c of 60- 80V is observed resulting in reduced end loss flux. The axial confinement time is improved by a factor of 2-3. By the additional application of the plug RF, the thermal barrier potential of phi B - 90 V is created with phi c - 100 V. The value of phi B increases with the plug RF power. it is likely that the barrier pumping is provided by the non-ambipolar ion convection driven by the azimuthal ponderomotive force of the plug cell RF.

RF 串联镜项目的主要目的是仅使用 ICRF 功率来演示纯轴对称磁场配置中的等离子体约束。我们发现，等离子体的产生、MHD 稳定、离子加热以及栓塞和热垒电势的形成都可以通过中心 RF 和栓塞 RF 的组合来实现。由螺旋/快波激发产生的最高峰值密度中心 RF 的辐射强度为 1.8X10^<13>cm^<-3>，对于氦等离子体，β 值为 - 10%。在两种离子种类的等离子体中，在0.4x10^13cm^-3的密度下已经实现了Ti_1-220eV的离子温度。这种加热是由于混合共振时螺旋/快波模式转换为慢阿尔文波所致。由于射频有质动力效应，等离子体是 MHD 稳定的。中央射频在插头中板处产生电位下降。这种下降是由插头电池中少数离子加热产生的晃动离子分布形成的。观察到插头电势 phi c 为 60-80V，导致端部损耗磁通减少。轴向限制时间提高了 2-3 倍。通过额外应用插头 RF，可以在 phi c - 100 V 的情况下创建 phi B - 90 V 的热障电势。 phi B 的值随着插头 RF 功率的增加而增加。势垒泵浦可能是由插头电池 RF 的方位有质动力驱动的非双极离子对流提供的。

项目成果

Y. YASAKA: "ICRF Stabilization and Potential Formation in HIEI" Proc. of Workshop on Control of Potential and Transport, pp.27-31, 1990.

Y. YASAKA：“HIEI 中 ICRF 的稳定和潜力形成”Proc。

Y.Yasaka: "Experiments on Effectiveness of Mode Controlled ICRF to both Axisymmetric Mirrors and Tokamaks" Plasma Physics and Controlled Nuclear Fusion Research. 1. 727-732 (1989)

Y.Yasaka：“模式控制 ICRF 对轴对称镜和托卡马克的有效性实验”等离子体物理和受控核聚变研究。

R.Itatani: "Experiments in the HIEI Tandem Mirror" Summary Report of Q-115 Workshop on Radial Transport in Tandem Mirrors(U.Wisconsin). (1989)

R.Itatani：“HIEI串联镜中的实验”Q-115串联镜径向传输研讨会的总结报告（威斯康星州威斯康星州）。

Y.YASAKA: Nuclear Fusion. 28. 1765-1770 (1988)

Y.YASAKA：核聚变。

H.HOJO: "Potential Enhancement due to RF-Induced Parallel Velocity Space Diffusion in a Tandem Mirror" J.Phys.Soc.Jpn. 59. 789-792 (1990)

H.HOJO：“串联镜中射频感应平行速度空间扩散的潜在增强”J.Phys.Soc.Jpn。