论文标题
使用现场粒子相关性诊断无碰撞能量转移:Alfven-Ion Cyclotron湍流
Diagnosing collisionless energy transfer using field-particle correlations: Alfven-Ion Cyclotron Turbulence
论文作者
论文摘要
我们应用现场粒子相关性(一种跟踪电磁场和等离子体颗粒之间能量密度转移速率的时间平均速度空间结构的技术),用于从混合Vlasov-Maxwell绘制的数据。与以前的现场粒子相关技术相关的系统不同,该系统中的能量传递预计将包括Landau和回旋波粒子共振。在此模拟中,由平行的电场$ e_ \ Parallel $介导的能量转移率约为总率的$ 60 \%$,其余由垂直电场$ e_ \ perp $介导。平行电场与质子共鸣,在整个仿真过程中,在许多点确定了Landau阻尼的规范双极速度空间特征。 $ e_ \ perp $介导的能量传递优先将$ v_ {tp} \ lyssim v_ \ perp \ perp \ lyssim 3 v_ {tp} $偶联,这与预期的环形体扩散高原的形成。我们的结果清楚地表明,现场粒子相关技术可以使用单点测量来区分不同的能量转移通道,即使在多个通道同时起作用的点,也可以用于定量确定每个通道中粒子能量的速率。
We apply field-particle correlations -- a technique that tracks the time-averaged velocity-space structure of the energy density transfer rate between electromagnetic fields and plasma particles -- to data drawn from a hybrid Vlasov-Maxwell simulation of Alfvén Ion-Cyclotron turbulence. Energy transfer in this system is expected to include both Landau and cyclotron wave-particle resonances, unlike previous systems to which the field-particle correlation technique has been applied. In this simulation, the energy transfer rate mediated by the parallel electric field $E_\parallel$ comprises approximately $60\%$ of the total rate, with the remainder mediated by the perpendicular electric field $E_\perp$. The parallel electric field resonantly couples to protons, with the canonical bipolar velocity-space signature of Landau damping identified at many points throughout the simulation. The energy transfer mediated by $E_\perp$ preferentially couples to particles with $v_{tp} \lesssim v_\perp \lesssim 3 v_{tp}$ in agreement with the expected formation of a cyclotron diffusion plateau. Our results demonstrate clearly that the field-particle correlation technique can distinguish distinct channels of energy transfer using single-point measurements, even at points in which multiple channels act simultaneously, and can be used to determine quantitatively the rates of particle energization in each channel.