Solitary magnetic structures known as SLAMS (short large‐amplitude magnetic structures) have been considered as essential elements of collisionless shocks with quasi‐parallel geometries. Yet the physics underlying their formation remains an open question. In this paper, we use measurements from the magnetospheric multiscale mission combined with fully kinetic simulations to study the formation of SLAMS. We find that gyro‐resonance between solar wind ions and right‐hand circularly polarized electromagnetic waves results in magnetic field amplification. Gyro‐trapping by the growing magnetic field buildup the plasma density that further enhances the current and field. The solitary nature of SLAMS stems from a beat‐like magnetic field envelope where the maximum sets the initial location for nonlinear growth. Our results present a conceptual advance on SLAMS, and may shed new light on the open question of magnetic field amplification at astrophysical shocks.

中文翻译：

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准平行无碰撞冲击下的孤立磁结构：形成

称为SLAMS（短大振幅磁性结构）的孤立磁性结构已被视为具有准平行几何形状的无碰撞冲击的基本要素。然而，形成它们的物理基础仍然是一个悬而未决的问题。在本文中，我们将磁层多尺度任务的测量结果与全动力学模拟相结合，以研究SLAMS的形成。我们发现，太阳风离子与右旋圆极化电磁波之间的陀螺共振会导致磁场放大。随着磁场的不断增加，陀螺陷阱会增加等离子体密度，从而进一步增强电流和磁场。SLAMS的孤立特性来自于像拍子一样的磁场包络，其中最大值决定了非线性增长的初始位置。