Small-Scale, Shear-Driven Irregularities and Associated Particle Heating

该提案的目的是利用实验室等离子体实验来确定与空间相关的波动、小尺度不规则和由速度剪切驱动机制引起的粒子加热的物理和特征特征。特别是，该项目将尝试，1.)确定Kelvin-Helmholz、非均匀能量密度驱动和电子-离子混合Kelvin-Helmholtz激发阈值与剪切参数的关系，2。测试在等离子体势中非线性演化的开尔文-亥姆霍兹旋涡边缘产生剪切驱动湍流的能力，3。区分不同剪切驱动波引起的离子加热和电流驱动波引起的离子加热，以及4.确定引入小浓度的第二种阳离子物种对上述第1-3项的影响。具体的长期目标是改进对极光弧缘和黑色极光中产生的动态强烈地磁活动的解释，并与用于解释空间观测的理论模型进行定量比较。

The objective of the proposal is to utilize laboratory plasma experiments to identify the physics and characterize the signatures of space-relevant fluctuations, small-scale irregularities, and particle heating induced by velocity-shear driven mechanisms. In particular, the project will attempt to, 1.) determine the dependence of Kelvin-Helmholz, inhomogeneous energy-density driven, and electron-ion hybrid Kelvin-Helmholtz excitation thresholds on shear parameters, 2.) test the ability to seed shear-driven turbulence at the edges of nonlinearly evolved Kelvin-Helmholtz vortices in plasma potential, 3.) distinguish the ion heating induced by different shear-driven waves from that resulting from current-driven waves, and 4.) determine the influence of introducing small concentrations of a second positive-ion species on items 1-3 above. The specific long range goals are to improve the interpretation of the dynamically intense geomagnetic activity that arises at the edges of auroral arcs and in black aurora and to provide quantitative comparisons to theoretical models used to interpret space observations.