论文标题
在MHD湍流中捕获宇宙射线
Trapping of cosmic rays in MHD turbulence
论文作者
论文摘要
天体物理等离子体是湍流和磁化的。宇宙射线（CRS）和磁流失动力（MHD）湍流之间的相互作用是一个基本的天体物理过程。基于当前对MHD湍流的理解，我们在MHD湍流的背景下重新审视了磁性镜的捕获。在可压缩的MHD湍流中，各向同性快速模式占据了CRS的捕获和回旋散射。捕获的存在显着抑制了螺距角散射和CRS沿磁场的空间扩散。所得的平行扩散系数在较高能量下对Cr能量的依赖性较弱。在不可压缩的MHD湍流中，伪alfvén模式的捕获在各种螺距角上由各向异性alfvén和伪alfvén模式占主导地位，并在所有螺距角度上占据主导地位，并导致CRS的扩散。
Astrophysical plasmas are turbulent and magnetized. The interaction between cosmic rays (CRs) and magnetohydrodynamic (MHD) turbulence is a fundamental astrophysical process. Based on the current understanding of MHD turbulence, we revisit the trapping of CRs by magnetic mirrors in the context of MHD turbulence. In compressible MHD turbulence, isotropic fast modes dominate both trapping and gyroresonant scattering of CRs. The presence of trapping significantly suppresses the pitch-angle scattering and the spatial diffusion of CRs along the magnetic field. The resulting parallel diffusion coefficient has a weaker dependence on CR energy at higher energies. In incompressible MHD turbulence, the trapping by pseudo-Alfvén modes dominates over the gyroresonant scattering by anisotropic Alfvén and pseudo-Alfvén modes at all pitch angles and prevents CRs from diffusion.
