Helicon Wave Studies

螺旋波是磁化等离子体中的有界电磁波，其频率介于离子回旋频率wci和电子回旋频率wce之间，满足wciwwce和wwcewpe2。它们很重要，因为它们不受等离子体密度的限制，而且它们代表着一种相对廉价的技术，可以在越来越多的应用中利用高等离子体密度。其中包括：大半径射频离子激光器；等离子体处理；用于加速器的多电荷离子源；用于集体等离子体加速器的离子推进器；用于基本等离子体实验的等离子体源。这些研究的目的是使螺旋子源适应大型稳态高密度等离子体(密度为1013 cm~(-3)-1014 cm~(-3)或更高)的有效产生和加热，探索目前的应用和寻找新的应用。研究将包括：径向功率沉积分布的控制；无密度截止的m=+1表面模；对源的有质量动力效应；磁流体稳定性；中性物的作用；以及脉冲源的特性。实验将建立在轴对称镜面等离子体(例如，有质动力和旋转场天线，允许控制方位射频模式)的过去经验的基础上。理论将把以前的分析理论扩展到更高的频率，并利用代码Antena的丰富经验来分析射频场数据。

Helicon waves are bounded electromagnetic waves in magnetized plasmas with frequencies between the ion cyclotron frequency wci and the electron gyrofrequency wce which satisfy wciwwce and wwcewpe2. They are important because they are not limited by plasma density, and they represent a relatively inexpensive technology that can be employed in a growing list of applications which can take advantage of high plasma density. These include: large radii RF ion lasers; plasma processing; sources of multi-charged ions for accelerators; in collective plasma accelerators; ion thrusters for spacecraft; and plasma sources for basic plasma experiments. The objective of these studies is the adaption of helicon sources to the efficient production and heating of large steady-state high density plasmas (with densities of 1013cm-3 - 1014cm-3 and higher), to explore the present applications and to find new applications. Studies will include: control of the radial power deposition profile; the m = + 1 surface mode which has no density cutoff; ponderomotive effects on source; magnetohydrodynamic stability; the role of neutrals; and characteristics of pulsed sources. Experiments will build on past experience with axisymmetric mirror plasmas (e.g. ponderomotive force and rotating field antennas which allow control of azimuthal rf modes). Theory will extend previous analytic theory to higher frequencies and take advantage of extensive experience with the code ANTENA to analyze rf field data.