EAGER: Addressing Key Unsolved Issues in Reconnection Physics Through Linear Theory of Tearing Instability

本项目将探讨一种新的方法来推导空间等离子体撕裂模式不稳定性的线性理论的可能性。这样的线性理论将会成为无碰撞等离子体中磁重联的完整非线性理论的基础。以前对线性撕裂模式的分析工作依赖于使用渐近方法来使方程易于处理。然而，完全动力学的粒子模拟表明，在大多数现实几何中，渐近方法是行不通的。本探索性研究的目的有三个：1)确定渐近方法失效的原因，并使用精确线性Vlasov解算器开发一种新方法来确定从线性理论直接过渡到非线性湍流发生的条件；2)确定二次撕裂岛形成是否由于线性不稳定；3)研究有争议的问题，即线性模态性质是否对大系统中产生的重联率有显著影响。这个项目有可能改变等离子体理论和模拟中处理磁重联的方式。它可能会影响我们对太阳、太阳风、行星磁层和天体物理等离子体现象的理解。

This project will investigate the possibility that a new approach to deriving a linear theory of the tearing mode instability in space plasmas can be successfully developed. Such a linear theory would then form the basis of a full non-linear theory of magnetic reconnection in a collisonless plasma. Previous analytical work on the linear tearing mode relied on using an asymptotic approach to make the equations tractable. However, fullly kinetic, particle simulations have indicated that the asymptotic approach breakes down in most realistic geometries. The purpose of this exploratory resarch is threefold: 1) Determine why the asymptotic appoach breaks down and develop a new approach using an exact linear Vlasov solver to determine the conditions where a direct transition from linear theory to non-linear turbulence occurs; 2) Determine whether or not the formation of secondary tearing island formation is due to a linear instability; 3) Examine the controversial question of whether linear mode properties have a significant influence on the resulting reconnection rate in large systems. This is a project that has the potential to transform the way magnetic reconnection is treated in plasma theory and simulations. It could affect our understanding of phenomena on the sun, in the solar wind, in planetary magnetospheres and in astrophysical plasmas.