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

这个项目将研究一种新的方法来成功地推导出空间等离子体中撕裂模不稳定性的线性理论的可能性。这样的线性理论将构成无胶原子等离子体中磁重联的完全非线性理论的基础。以前关于线性撕裂模的分析工作依赖于使用渐近方法来使方程易于处理。然而，完全动态的粒子模拟表明，渐近方法在大多数逼真的几何图形中是错误的。这项探索性研究的目的有三个：1)确定渐近近似分解的原因，并发展一种新的方法，使用精确的线性Vlasov求解器来确定发生从线性理论到非线性湍流的直接转变的条件；2)确定二次撕裂岛的形成是否由于线性不稳定性；3)检验有争议的问题，即线性模式特性是否对大系统中由此产生的重联率有显著影响。这是一个有可能改变等离子体理论和模拟中处理磁重联的方式的项目。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.