A hybrid-kinetic model for high-$beta$ plasmas
A hybrid-kinetic model (Vlasov ions and drift-kinetic electrons) is developed to describe the equilibrium and stability properties of collisionless high-beta plasmas in arbitrary magnetic field configurations. No ordering of ion properties (such as $omega$$/$$Omega$/subi/ and r/subL//subi//L/sub perpendicular/) is assumed, so the ions are described by the exact (unexpanded) Vlasov equation. The electrons are assumed to be strongly magnetized with $omega$$/$$Omega$/sube/ approx.r/subL//sube//L/sub perpendicular/=epsilonvery-much-less-than1, and the electron Vlasov equation is expanded in epsilon to give a drift-kinetic equation for f/sube/. Examples of linear screw-pinch equilibria are constructed to demonstrate the ease with which equilibrium solutions are found within this formalism. Also, it is shown that the hybrid-kinetic model correct to O (epsilon) includes physical effects which are important during the implosion and immediate post-implosion phases of high-density pinch experiments, where stability behavior is characterized by the fast time scale $omega$$sup -1$/subL// subH/= ($Omega$/sube/$Omega$/subi/)$sup -1$$/$$sup 2$. In particular, a local dispersion relation is derived for the modified-two-stream and lower-hybrid-drift instabilities, which have characteristic growth rates of order ($Omega$/sube/ $Omega$/subi/)$sup 1$$/$$sup 2$ when $omega$$sup 2$/subp//sube//$Omega$$sup 2$/sube/ very-much-greater-than1. (AIP)
- Research Organization:
- Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742
- NSA Number:
- NSA-33-014474
- OSTI ID:
- 4111441
- Journal Information:
- Phys. Fluids, v. 18, no. 11, pp. 1507-1523, Journal Name: Phys. Fluids, v. 18, no. 11, pp. 1507-1523; ISSN PFLDA
- Country of Publication:
- United States
- Language:
- English
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