An Obliquely Propagating Electromagnetic Drift Instability in the Lower Hybrid Frequency Range

Technical Report · Fri Jun 10 04:00:00 EDT 2005

DOI:https://doi.org/10.2172/841011· OSTI ID:841011

Ji, Hantao ^[1]; Kulsrud, Russell; Fox, William; Yamada, Masaaki

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1. Princeton Plasma Physics Laboratory

By employing a local two-fluid theory, we investigate an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field current or relative drifts between electrons and ions. The theory self-consistently takes into account local cross-field current and accompanying pressure gradients. It is found that the instability is caused by reactive coupling between the backward propagating whistler (fast) waves in the moving electron frame, and the forward propagating sound (slow) waves in the ion frame when the relative drifts are large. The unstable waves we consider propagate obliquely to the unperturbed magnetic field and have mixed polarization with significant electromagnetic components. A physical picture of the instability emerges in the limit of large wave number characteristic of the local approximation. The primary positive feedback mechanism is based on reinforcement of initial electron density perturbations by compression of electron fluid via induced Lorentz force. The resultant waves are qualitatively consistent with the measured electromagnetic fluctuations in reconnecting current sheet in a laboratory plasma.

• Research Organization: Princeton Plasma Physics Lab., Princeton, NJ (US)
• Sponsoring Organization: US Department of Energy; USDOE Office of Science (SC) (US)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 841011
• Report Number(s): PPPL-4078
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPRESSION
DRIFT INSTABILITY
ELECTRON DENSITY
ELECTRONS
FEEDBACK
FLUCTUATIONS
FREQUENCY RANGE
INSTABILITY
LANDAU LIQUID HELIUM THEORY
LORENTZ FORCE
LOWER HYBRID WAVES
MAGNETIC FIELDS
MAGNETIC RECONNECTION
PLASMA
POLARIZATION
PRESSURE GRADIENTS
STABILITY
MICROINSTABILITY
WHISTLERS