TY - JOUR
T1 - The 90° problem of scattering theory revisited
T2 - Dynamical turbulence versus nonlinear effects
AU - Dosch, A.
AU - Kourakis, I.
AU - Shalchi, A.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - The 90° problem of cosmic-ray transport theory is revisited in this paper. By using standard forms of the wave spectrum in the solar wind, the pitch-angle Fokker-Planck coefficient and the parallel mean free path are computed for different resonance functions. A critical comparison is made of the strength of 90° scattering due to plasmawave effects, dynamical turbulence effects and nonlinear effects. It is demonstrated that, only for low-energy cosmic particles, dynamical effects are usually dominant. The novel results presented here are essential for an effective comparison of heliospheric observations for the parallel mean free path with the theoretical model results.
AB - The 90° problem of cosmic-ray transport theory is revisited in this paper. By using standard forms of the wave spectrum in the solar wind, the pitch-angle Fokker-Planck coefficient and the parallel mean free path are computed for different resonance functions. A critical comparison is made of the strength of 90° scattering due to plasmawave effects, dynamical turbulence effects and nonlinear effects. It is demonstrated that, only for low-energy cosmic particles, dynamical effects are usually dominant. The novel results presented here are essential for an effective comparison of heliospheric observations for the parallel mean free path with the theoretical model results.
UR - http://www.scopus.com/inward/record.url?scp=36348974605&partnerID=8YFLogxK
U2 - 10.1088/0954-3899/34/12/006
DO - 10.1088/0954-3899/34/12/006
M3 - Article
AN - SCOPUS:36348974605
SN - 0954-3899
VL - 34
SP - 2595
EP - 2610
JO - Journal of Physics G: Nuclear and Particle Physics
JF - Journal of Physics G: Nuclear and Particle Physics
IS - 12
ER -