On the bounce-averaging of scattering rates and the calculation of bounce period

Journal Article · Thu Sep 15 00:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3638137· OSTI ID:22043513

Orlova, K G ^[1]; Shprits, Y Y ^[2]

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1. Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095 (United States)
2. Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095 (United States)

For many applications to planetary magnetospheres and elsewhere in the Universe, it is desirable to average physical quantities such as particle and plasma transport coefficients over a charged particle's bounce motion between magnetic mirror points along field lines. In this paper, we perform such bounce-averaging in a way that avoids singularities in the integrands of expressions that arise in calculations of this sort. Our method applies in principle to an almost arbitrary magnetic field model. We illustrate the advantage of using our method for removing the integrand's singularity through a change of variables (rather than by truncating the integral over latitude at points progressively nearer to the mirror point) by computing the component of the bounce-averaged momentum-space diffusion tensor in a dipolar magnetic field both ways for resonance interaction of geomagnetically trapped relativistic (1 MeV) electrons with field-aligned whistler-mode plasma waves at L = 6 (a field line that passes near synchronous altitude). Moreover, we develop improved analytical approximations for particle bounce periods in a dipolar magnetic field by minimizing mean square errors with respect to expansion coefficients in algebraic representations of the bounce period.

• OSTI ID: 22043513
• Journal Information: Physics of Plasmas, Vol. 18, Issue 9; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
APPROXIMATIONS
CHARGED PARTICLES
DIFFUSION
EXPANSION
INTERACTIONS
MAGNETIC FIELDS
MAGNETIC MIRRORS
MEV RANGE 01-10
MIRRORS
PLANETARY MAGNETOSPHERES
PLASMA WAVES
RELATIVISTIC PLASMA
RELATIVISTIC RANGE
RESONANCE
SCATTERING
TRAPPING
UNIVERSE
WHISTLER INSTABILITY
WHISTLERS