International School of Cosmic Ray Astrophysics
<<Maurice M. Shapiro>>
21st Course: Astroparticle Physics: Yesterday, Today, and Tomorrow
1-7 August, 2018
1-7 August, 2018
LECTURER: Reinhard Schlickeiser
Location:
For linear MHD plasma waves the ordering B0 B E, necessary for explaining the
observed nearly isotropic cosmic ray momentum distribution functions, is the basis for
a quasilinear perturbation scheme. This perturbation scheme leads to the small cosmic
ray anisotropy and to the diusion-convection cosmic ray transport equation for the
isotropic part of the cosmic ray distribution function. Augmented with the continuous
and catastrophic momentum loss rates, the diusion-convection cosmic ray transport
equation describes all electromagnetic acceleration and transport processes discussed
today, including diusive shock acceleration and stochastic acceleration.
The determination of the cosmic ray transport parameters (spatial and momentum
diusion coecients, spatial and momentum convection rates) requires the knowledge
of the second-order correlation functions of electromagnetic
uctuations, either from
observations in the interplanetary medium or from
uctuation theory.
By expanding in terms of the eigenfunctions of the spatial diusion operator the solu-
tion of the diusion-convection transport equation can be expressed as an innite sum
where the momentum dependent expansion coecients obey simpler leaky-box equa-
tions. The conditions for generating power-law distribution functions are discussed.