ExB flow shear and enhanced confinement in the Madison Symmetric Torus reversed-field pinch

被引:23
作者
Chapman, BE [1 ]
Almagri, AF [1 ]
Anderson, JK [1 ]
Chiang, CS [1 ]
Craig, D [1 ]
Fiksel, G [1 ]
Lanier, NE [1 ]
Prager, SC [1 ]
Sarff, JS [1 ]
Stoneking, MR [1 ]
Terry, PW [1 ]
机构
[1] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
关键词
D O I
10.1063/1.872855
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
Strong ExB flow shear occurs in the edge of three types of enhanced confinement discharge in the Madison Symmetric Torus [Dexter ct al., Fusion Technol. 19, 131 (1991)] reversed-field pinch. Measurements in standard (low confinement) discharges indicate that global magnetic fluctuations drive particle and energy transport in the plasma core, while electrostatic fluctuations drive particle transport in the plasma edge. This paper explores possible contributions of ExB flow shear to the reduction of both the magnetic and electrostatic fluctuations and, thus, the improved confinement. In one case, shear in the ExB flow occurs when the edge plasma is biased. Biased discharges exhibit changes in the edge electrostatic fluctuations and improved particle confinement. In two ether cases, the flow shear emerges (1) when auxiliary current is driven in the edge and (2) spontaneously, following sawtooth crashes. Both edge electrostatic and global magnetic fluctuations are reduced in these discharges, and both particle and energy confinement improve. (C) 1998 American Institute of Physics.
引用
收藏
页码:1848 / 1854
页数:7
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