Triggered Auroral Kilometric Radiation

9312013卡尔弗特极光电子沉淀假定是在极光千米辐射(AKR)产生过程中，回旋脉泽不稳定性导致电子俯仰角散射的结果。AKR由强烈的、主要是非常模的波组成，这些波起源于地心高度为1.3到3.3地球半径的极光磁力线。AKR占极光总能量的百分之一，现在人们普遍认为它是由回旋脉泽不稳定性产生的，回旋脉泽不稳定性是高能电子进入损失锥的多普勒频移、回旋共振、俯仰角散射造成的。这一新的极光理论的关键是解释观测到的太阳无线电波触发AKR的原因，因为这一现象清楚地证实了新的理论。拟议的工作是研究这一触发，据信是由于环境密度极小值中的局部降水增加以及随之而来的可能发生射电激光的密度损耗造成的。这种射电激光由源上的波反射引起的闭环波反馈振荡组成，完全类似于传统的光学激光器，并同样产生近乎完美的离散、相干和单色发射。***

9312013 Calvert Auroral electron precipitation is hypothesized to result from electron pitch-angle scattering by the cyclotron maser instability during the generation of auroral kilometric radiation (AKR). The AKR consists of intense, primarily extraordinary-mode waves originating on auroral magnetic field lines at geocentric altitudes of 1.3 to 3.3 earth radii. Comprising up to one percent of the total power of the aurora the AKR is now widely believed to be generated by the cyclotron maser instability which results from the doppler-shifted, cyclotron-resonant, pitch-angle scattering of energetic electrons into the loss cone. Critical to this new theory of the aurora is explaining the observed triggering of the AKR by radio waves from the sun, since that phenomenon clearly confirms the new theory. The proposed work is to study this triggering, believed to be caused by enhanced local precipitation in ambient density minima and the consequent creation of density depletions in which radio lasing can occur. Such radio lasing consists of closed-loop wave feedback oscillations caused by wave reflections at the source, exactly analogous to those of conventional optical lasers and likewise producing nearly-perfect discrete, coherent, and monochromatic emissions. ***