Two-dimensional axisymmetric and three-dimensional helical equilibrium in the line-tied screw pinch
Two-dimensional axisymmetric and three-dimensional helical equilibrium in the line-tied screw pinch
复制标题
线绑螺钉夹紧中的二维轴对称和三维螺旋平衡
DOI：
10.1063/1.3592998
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发表时间：
2011
影响因子：
2.2
通讯作者：
C. Forest
中科院分区：
文献类型：
--
作者：
C. Paz;M. Brookhart;A. Clinch;D. Hannum;C. Forest
在导电阳极处的线连接条件被证明是对体等离子体抗磁性存在时人们熟知的一维螺旋收缩平衡的局部修正。抗磁电流不能在导电阳极附近流动，并被测量为在局部边界层中消失，导致微弱的镜面构型，打破一维平衡，并产生大的平行压力梯度，暗示着显著的径向外流。对于足够大的等离子体电流，平行电流的顺磁性质将平衡推向顺磁，并破坏镜面效应。在临界等离子体电流下，轴对称平衡转变为长寿命、旋转、螺旋的三维平衡状态。通过多点相关分析技术对这种状态的内部测量表明，它保留了轴对称平衡的流量面和压力分布。测量表明，尽管磁通表面在阳极处漂移，但不一定违反线约束边界条件。
The line-tying condition at a conducting anode is shown to provide a localized modification to the well-understood 1-D screw pinch equilibrium in the presence of bulk plasma diamagnetism. Diamagnetic currents cannot flow near the conducting anode and are measured to disappear in a localized boundary layer, causing a weak mirror configuration that breaks 1-D equilibrium and causes large parallel pressure gradients suggestive of significant radial outflows. For sufficiently large plasma currents, the paramagnetic nature of parallel current drives the equilibrium to paramagnetism and destroys the mirror effect. At a critical plasma current, the axisymmetric equilibrium is found to transition to a long-lived, rotating, helical 3-D equilibrium state. Internal measurements of this state via multi-point correlation analysis techniques illustrate that it preserves the flux surfaces and pressure profile of the axisymmetric equilibrium. Measurements indicate that despite the fact that the flux surfaces wander at the anode, the line-tied boundary conditions are not necessarily violated.