Study on a Current Channel Shrinkage and a Heating Enhancement Due to a Maqnetic Compressionof ULQ Plasmas

ULQ等离子体磁力压缩引起的电流通道收缩和加热增强的研究

• 批准号: 04402049
• 负责人: OGAWA Yuichi
• 金额: $ 21.76万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04402049/
• 关键词: Plasma; Nuclear Fusion; ULQ; VLQ; Magnetic compression; Magnetic fluctuations; H_<alpha> signal; Ion anomalous heating; Dynamo electric field; H_αシグナル; 異常加熱; MHD緩和; 不純物輸送; プラズマ・壁相互作用

The magnetic compresseion has been applied for a Ultra-low-q (ULQ) plasma with a safety factor q (a) of less than unity, where the toroidal magetic field B_t was increased from 0.1 T to 0.3 T.During the magnetic compression phase, the increases of the loop voltage and magnetic fluctuations have been observed, indicating the enhancement of the resistance anomaly. This might be accounted for a poloidal electric field induced by the rapid increase of the toroidal magnetic field, the direction of which is opposite to the incident dynamo electric field. H_<alpha> signals have drastically suppressed during the magnetic compression, accompanied by the shrinkage of the plasma column with a few centimenter.Just after the magnetic compression the plasma current begins to increase, and the loop voltage and magentic fluctuations are kept at low levels during this phase. Compared with the scaling of resistance anomaly for ULQ plasmas, the plasma resistance of this phase is quite low, and more stable and quiescent ULQ plasmas have been realized by applying the magnetic compression for ULQ plasmas. This stable ULQ configuration terminates when the rational surface appears at the plasma surface, accompanied by the increase of magnetic fluctuations and the anomalous ion heating. It is found that the magnetic compression is very powerful to introduce an externally-induced poloidal electric field and to understand the role of the dynamo electric field in ULQ plasmas.

对安全系数q (a)小于1的超低q （ULQ）等离子体进行磁压缩，环形磁场B_t从0.1 T增加到0.3 T。在磁压缩阶段，观察到回路电压和磁波动的增加，表明电阻异常增强。这可能是由于环形磁场的迅速增加所引起的极向电场，其方向与入射发电机电场相反。磁压缩过程中，H_< α >信号被剧烈抑制，等离子体柱收缩了几厘米。磁压缩后，等离子体电流开始增加，环路电压和磁波动在这一阶段保持在较低水平。与超低密度等离子体电阻异常的标度相比，该相位的等离子体电阻很低，通过对超低密度等离子体进行磁压缩可以实现更稳定、更静态的超低密度等离子体。当合理表面出现在等离子体表面时，伴随着磁波动的增加和异常离子加热，这种稳定的ULQ结构终止。发现磁压缩对引入外感极向电场和理解发电机电场在超光速等离子体中的作用是非常有力的。

项目成果

S.Shinohara,S.Ohadaci et al.: "Movable Limiter Insertion and First Pump Limiter Experiments in a Reversed-Field Pinch" Physics of Fluid B. 5. 464-470 (1993)

S.Shinohara、S.Ohadaci 等人：“反向场收缩中的可移动限制器插入和第一泵限制器实验”流体物理学 B. 5. 464-470 (1993)

Z.Yshida and A.Hasegawa: "Transit-time Magnetic Pumping Induced by Spontaneous Fluctumatuons in a Magnetohynamic Relazation Process" Phtsics of Fluids B. 4. 3013-3015 (1992)

Z.Yshida 和 A.Hasekawa：“磁力松弛过程中自发波动引起的渡越磁泵浦”流体物理学 B.4. 3013-3015 (1992)

Z.Yoshida: "Self-Organization and Anomalous Heating in Plasmas" Butsuri. 48. 73-78 (1993)

Z.Yoshida：“等离子体中的自组织和异常加热”Butsuri。

S.Shinohara,S.Ohdachi et al.: "Movable Limiter Insertion and First Pump Limiter Experiments in a Reversed-Field Pinch" Physics of Fluid B. 5. 464-470 (1993)

S.Shinohara、S.Ohdachi 等人：“反向场收缩中的可移动限制器插入和第一泵限制器实验”流体物理学 B. 5. 464-470 (1993)

Z.Yoshida and A.Hasegawa: "Transit-Time Magnetic Pumping Induced by Spontaneous Fluctuations in a Magnetohydrodynamic Relaxation Process" Physics of Fluid B. 4. 3013-3015 (1992)

Z.Yoshida 和 A.Hasekawa：“磁流体动力学弛豫过程中自发波动引起的时空磁泵浦”流体物理学 B.4. 3013-3015 (1992)