On a variational formulation of the weakly nonlinear magnetic Rayleigh–Taylor instability
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
The magnetic-Rayleigh–Taylor (MRT) instability is a ubiquitous phenomenon that occurs in magnetically-driven Z-pinch implosions. It is important to understand this instability since it can decrease the performance of such implosions. In this work, I present a theoretical model for the weakly nonlinear MRT instability. I obtain such a model by asymptotically expanding an action principle, whose Lagrangian leads to the fully nonlinear MRT equations. After introducing a suitable choice of coordinates, I show that the theory can be cast as a Hamiltonian system, whose Hamiltonian is calculated up to the sixth order in a perturbation parameter. The resulting theory captures the harmonic generation of MRT modes. It is shown that the amplitude at which the linear magnetic-Rayleigh–Taylor instability exponential growth saturates depends on the stabilization effect of the magnetic-field tension. Overall, the theory provides an intuitive interpretation of the weakly nonlinear MRT instability and provides a systematic approach for studying this instability in more complex settings.
- Research Organization:
- Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC04-94AL85000; NA0003525
- OSTI ID:
- 1605728
- Alternate ID(s):
- OSTI ID: 1601906
OSTI ID: 1646039
- Report Number(s):
- SAND--2020-2688J; 684470
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 27; ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nonlinear Rayleigh-Taylor instabilities in fast Z pinches
Nonlinear Rayleigh-Taylor instabilities in fast z-pinches
Effects of compressibility on the magneto-Rayleigh-Taylor instability in Z-pinch implosions with sheared axial flows
Journal Article
·
Sun Mar 15 00:00:00 EDT 2009
· Physics of Plasmas
·
OSTI ID:21274185
Nonlinear Rayleigh-Taylor instabilities in fast z-pinches
Journal Article
·
Tue Sep 16 00:00:00 EDT 2008
· Physics of Plasmas
·
OSTI ID:965069
Effects of compressibility on the magneto-Rayleigh-Taylor instability in Z-pinch implosions with sheared axial flows
Journal Article
·
Tue Feb 14 23:00:00 EST 2006
· Physics of Plasmas
·
OSTI ID:20782510