arXiv 1710.033392017-10-09physics.plasm-ph

静电驱动螺旋等离子体态的性质

Properties of the electrostatically driven helical plasma state

Cihan Akçay, John M. Finn, Richard A. Nebel, Daniel C. Barnes, Neal Martin

DOI：: 10.1063/1.5006902

摘要：

发现了一种新的等离子体态[C.~ Akçay，J.~ Finn，R.~ Nebel和D.~巴恩斯，物理。等离子体\textbf{24}，052503（2017）]在周期性圆柱形几何形状中存在均匀施加的轴向磁场。该状态由螺旋电极提供的外部静电场驱动，并且取决于半径$r<r_w$和$mθ-nζ$，其中$m=n=1$、$θ$是极向角，并且$ζ=z/R$是环向角。在该文献中，发现强驱动形式的状态具有强的轴向平均电流密度，平均场线安全系数$q_0(r)$刚好高于内部电极的间距$m/n=1$，其中等离子体几乎是无力的。然而，在边缘处，电流密度具有垂直于$\mathbf{B}$的分量。这种垂直的电流密度驱动着近似Alfvénic螺旋的等离子体流，这是这些状态的一个显著特征。这种状态正在研究其可能的应用直流Transformers和可能的定制电流分布在托卡马克。我们提出了几个重要问题的结果，这些应用：瞬态导致的稳定状态，扭曲和扭曲的磁力线和它们与电流密度的关系，电流密度流线的性质和连接到电极的电流密度线的长度，速度边界条件的变化的敏感性，改变径向电阻率剖面的影响，以及集中的电极电势的影响。

英文摘要：

A novel plasma state has been found [C.~Akçay, J.~Finn, R.~Nebel and D.~Barnes, Phys.~Plasmas \textbf{24}, 052503 (2017)] in the presence of a uniform applied axial magnetic field in periodic cylindrical geometry. This state is driven by external electrostatic fields provided by helical electrodes, and depends on radius $r<r_w$ and $mθ-nζ$, where $m=n=1$, $θ$ is the poloidal angle, and $ζ=z/R$ is the toroidal angle. In this reference, the strongly driven form of the state was found to have a strong axial mean current density, with a mean-field line safety factor $q_0(r)$ just above the pitch of the electrodes $m/n=1$ in the interior, where the plasma is nearly force-free. However, at the edge the current density has a component perpendicular to $\mathbf{B}$. This perpendicular current density drives nearly Alfvénic helical plasma flows, an notable feature of these states. This state is being studied for its possible application to DC electrical transformers and possibly tailoring the current profile in tokamaks. We present results on several issues of importance for these applications: the transient leading to the steady state; the twist and writhe of the field lines and their relation with the current density; the properties of the current density streamlines and length of the current density lines connected to the electrodes; the sensitivity to changes in the velocity boundary conditions; the effect of varying the radial resistivity profile; and the effects of a concentrated electrode potential.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文