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Title: ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the κ distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized κ distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index α, where f{sub e} ∼ v {sup –α} is close to the average index observed during the quiet-time solar wind condition, i.e., α ∼ O(6.5) whereas α{sub average} ∼ 6.69, accordingmore » to observation.« less
Authors:
 [1] ;  [2]
  1. Permanent address: Department of Physics, Forman Christian College, Lahore, Punjab 54000, Pakistan. (Pakistan)
  2. Also at SSR, KHU, Yongin, Korea. (Korea, Republic of)
Publication Date:
OSTI Identifier:
22270848
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 775; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; ASTROPHYSICS; ASYMPTOTIC SOLUTIONS; DISTRIBUTION FUNCTIONS; ELECTRONS; INDEXES; KINETIC EQUATIONS; LANGMUIR FREQUENCY; NONLINEAR PROBLEMS; SOLAR WIND; SUN; TURBULENCE