Finite Larmor radius magnetohydrodynamics of the Rayleigh{endash}Taylor instability
- Beam Physics Branch, Plasma Physics Division, Naval Research Laboratory, Washington, D.C. 20375 (United States)
The evolution of the Rayleigh{endash}Taylor instability is studied using finite Larmor radius (FLR) magnetohydrodynamic (MHD) theory. Finite Larmor radius effects are introduced in the momentum equation through an anisotropic ion stress tensor. Roberts and Taylor [Phys. Rev. Lett. {bold 3}, 197 (1962)], using fluid theory, demonstrated that FLR effects can stabilize the Rayleigh{endash}Taylor instability in the short-wavelength limit ({ital kL}{sub {ital n}}{gt}1, where {ital k} is the wave number and {ital L}{sub {ital n}} is the density gradient scale length). In this paper a linear mode equation is derived that is valid for arbitrary {ital kL}{sub {ital n}}. Analytic solutions are presented in both the short-wavelength ({ital kL}{sub {ital n}}{gt}1) and long-wavelength ({ital kL}{sub {ital n}}{lt}1) regimes, and numerical solutions are presented for the intermediate regime ({ital kL}{sub {ital n}}{approximately}1). The long-wavelength modes are shown to be the most difficult to stabilize. More important, the nonlinear evolution of the Rayleigh{endash}Taylor instability is studied using a newly developed two-dimensional (2-D) FLR MHD code. The FLR effects are shown to be a stabilizing influence on the Rayleigh{endash}Taylor instability; the short-wavelength modes are the easiest to stabilize, consistent with linear theory. In the nonlinear regime, the FLR effects cause the {open_quote}{open_quote}bubbles and spikes{close_quote}{close_quote} that develop because of the Rayleigh{endash}Taylor instability to convect along the density gradient and to tilt. Applications of this model to space and laboratory plasma phenomena are discussed. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 285571
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Finite Larmor radius magnetohydrodynamic analysis of the Rayleigh-Taylor instability in Z pinches with sheared axial flow
Regimes of the magnetized Rayleigh{endash}Taylor instability