Particle acceleration in step function shear flows: A microscopic analysis

J. Randy Jokipii, G. E. Morfill

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

We present a discussion of the transport of energetic particles in a moving, scattering fluid, which has a large shear in its velocity over a distance small compared with the scattering mean free path. The analysis is complementary to an earlier paper by Earl, Jokipii, and Morfill, which considered effects of more-gradual shear in the diffusion approximation. In the present paper we consider the case in which the scattering fluid undergoes a step function change in velocity, in the direction normal to the flow. We present both an analytical, approximate calculation and a Monte Carlo analysis of particle motion. We find that particles gain energy at a rate proportional to the square of the magnitude of the velocity change. Application to the boundary of a magnetosphere suggests significant acceleration of the particles.

Original languageEnglish (US)
Pages (from-to)255-258
Number of pages4
JournalAstrophysical Journal
Volume356
Issue number1
StatePublished - Jun 10 1990

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step functions
shear flow
particle acceleration
scattering
shear
Monte Carlo analysis
particle motion
fluid
fluids
energetic particles
magnetospheres
mean free path
magnetosphere
energetics
approximation
energy
analysis
particle

Keywords

  • Cosmic rays: general
  • Hydrodynamics
  • Particle acceleration

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Particle acceleration in step function shear flows : A microscopic analysis. / Jokipii, J. Randy; Morfill, G. E.

In: Astrophysical Journal, Vol. 356, No. 1, 10.06.1990, p. 255-258.

Research output: Contribution to journalArticle

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