Cosmic ray streaming in the diffusion approximation
Heading:
| 1Fedorov, YI 1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2021, 37(3):3-23 |
| https://doi.org/10.15407/kfnt2021.03.003 |
| Start Page: Space Physics |
| Language: Ukrainian |
Abstract: The propagation of cosmic rays in the interplanetary medium is considered based on the kinetic Fokker-Planck equation. The analytical expression for anisotropic part of cosmic ray distribution function is derived in the approximation of the small anisotropy. It is shown that under isotropic scattering of energetic charged particles on interplanetary magnetic field fluctuations the cosmic ray distribution function depends exponentially on the cosine of the angle between particle velocity and radial direction. The expression for the cosmic ray streaming density is obtained. It is shown that the value of the particle streaming density is defined by the spatial distribution of the cosmic ray density and by the temporal dependence of the particle density. The cosmic ray transport equations have been derived (the hyperdiffusion equation and the telegraph equation). On the basis of these equations the spatio-temporal distribution of solar cosmic ray intensity and the anisotropy of the particle angular distribution are investigated. |
| Keywords: cosmic rays, interplanetary medium, kinetic equation, transport equation |
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