Cosmic-ray pitch angle scattering in isotropic turbulence. II. Sensitive dependence on the dissipation range spectrum

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169340· OSTI ID:6265299

Smith, C W; Bieber, J W; Matthaeus, W H ^[1]

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1. Bartol Research Institute, Newark, DE (USA)

The leading-order quasi-linear expressions for cosmic-ray pitch-angle scattering in isotropic magnetic turbulence were analyzed using three separate spectral forms: the Gaussian, the exponential, and the power-law. It is shown that the low-energy limit for the pitch-angle diffusion coefficient did not universally yield the slab results obtained with a Gaussian dissipation range by Bieber et al. (1988). Instead, it was found that the low-energy limit depends on the steepness of the dissipation range spectrum, and the asymptotic functional forms can range between the slab results and the Fisk et al. (1974) results. It is also shown that the 90-deg pitch-angle limit displays a sensitive dependence on the form of the dissipation range spectrum and can depart dramatically from either the slab result or the result of Fisk. 41 refs.

• OSTI ID: 6265299
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 363; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED PARTICLES
COSMIC RADIATION
DIFFERENTIAL EQUATIONS
DIFFUSION
ENERGY LOSSES
EQUATIONS
FLUID MECHANICS
FOKKER-PLANCK EQUATION
HYDRODYNAMICS
IONIZING RADIATIONS
ISOTROPY
LOSSES
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
PARTIAL DIFFERENTIAL EQUATIONS
QUASILINEAR PROBLEMS
RADIATIONS
SCATTERING
SOLAR ACTIVITY
SOLAR WIND
TURBULENCE