标题： 脉冲星磁层中双生产极限环的模型 显示英文标题

标题： A Model for Pair Production Limit Cycles in Pulsar Magnetospheres

摘要： 最近有人提出，由于自洽的$e^{\pm}$对产生而导致的电场振荡可能是脉冲星相干射电辐射的来源。 对此过程的直接粒子模拟（PIC）显示，由于该对级联屏蔽了平行电场，当级联中产生的对逃离间隙区域时，平行电场会反复被激发，从而表现为一个极限环。 在本工作中，我们开发了一个简化的随时间变化的动能模型，用于描述脉冲星磁层中的$e^{\pm}$对级联，该模型能够再现对产生和电场屏蔽的极限环行为。 该模型包括磁层电流的影响、$e^{\pm}$的逃逸以及对产生率与等离子体密度和能量的动态依赖关系。 利用这个简单的理论模型，我们表明，在多个极限环上平均的电场振荡功率谱与观测到的脉冲星射电谱相容。 显示英文摘要

摘要： It was recently proposed that the electric field oscillation as a result of self-consistent $e^{\pm}$ pair production may be the source of coherent radio emission from pulsars. Direct Particle-in-Cell (PIC) simulations of this process have shown that the screening of the parallel electric field by this pair cascade manifests as a limit cycle, as the parallel electric field is recurrently induced when pairs produced in the cascade escape from the gap region. In this work, we develop a simplified time-dependent kinetic model of $e^{\pm}$ pair cascades in pulsar magnetospheres that can reproduce the limit-cycle behavior of pair production and electric field screening. This model includes the effects of a magnetospheric current, the escape of $e^{\pm}$, as well as the dynamic dependence of pair production rate on the plasma density and energy. Using this simple theoretical model, we show that the power spectrum of electric field oscillations averaged over many limit cycles is compatible with the observed pulsar radio spectrum.