Second-order quasilinear theory of cosmic ray transport
- Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum und Astrophysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)
The problem of pitch-angle diffusion close to 90 deg. is well known in cosmic ray astrophysics. If the pitch-angle Fokker-Planck coefficient for pure slab geometry is calculated, the quasilinear approximation results in vanishing pitch-angle scattering. For a realistic wave spectrum with a steep dissipation range this vanishing coefficient generates an infinitely large parallel mean free path. It is well known from numerical simulations that the 90 deg. problem is a problem of quasilinear theory and not a problem of reality. In the current paper quasilinear theory is used to calculate corrections of the unperturbed orbit. These corrections can be resubstituted into transport theory to calculate a second-order pitch-angle Fokker-Planck coefficient. The second-order quasilinear theory is an applicable theory which agrees with simulations for pitch-angle diffusion.
- OSTI ID:
- 20722104
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Detailed numerical investigation of 90∘ scattering of energetic particles interacting with magnetic turbulence
A NEW COSMIC RAY TRANSPORT THEORY IN PARTIALLY TURBULENT SPACE PLASMAS: EXTENDING THE QUASILINEAR APPROACH
PITCH-ANGLE DIFFUSION COEFFICIENTS OF CHARGED PARTICLES FROM COMPUTER SIMULATIONS
Journal Article
·
Tue Apr 15 00:00:00 EDT 2014
· Physics of Plasmas
·
OSTI ID:22253010
A NEW COSMIC RAY TRANSPORT THEORY IN PARTIALLY TURBULENT SPACE PLASMAS: EXTENDING THE QUASILINEAR APPROACH
Journal Article
·
Tue May 10 00:00:00 EDT 2011
· Astrophysical Journal
·
OSTI ID:21576865
PITCH-ANGLE DIFFUSION COEFFICIENTS OF CHARGED PARTICLES FROM COMPUTER SIMULATIONS
Journal Article
·
Wed Dec 09 23:00:00 EST 2009
· Astrophysical Journal
·
OSTI ID:21389342