Drift-cyclotron instability with trapped particle effects in a linear multiple mirror

Journal Article · Sun Sep 01 04:00:00 EDT 1985 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.865203· OSTI ID:5424344

Makowski, M A; Emmert, G A

A drift-cyclotron instability is observed at low magnetic field strengths in a linear multiple mirror. It is characterized by a frequency which decreases with increasing magnetic field strength, propagation in the direction of the electron diamagnetic current, and an azimuthal mode number of 2. The mode is observed when the ion-cyclotron frequency is less than the ion diamagnetic frequency. The frequency is Doppler-shifted by an E x B drift. Effects of particles trapped in the mirror cells alter the characteristics of the instability. The frequency decreases slightly and the fluctuation level increases with increasing mirror ratio for mirror ratios less than 1.1, but then levels off at higher mirror ratios. The drift wave is analyzed by a linear theory which treats finite ion gyroradius, an electron temperature gradient, and trapped electrons. The theory predicts three unstable modes, only one of which is consistent with all of the above measurements. This instability is a Doppler-shifted drift-cyclotron instability modified by trapped particle effects.

• Research Organization: University of Wisconsin, Madison, Wisconsin 53706
• OSTI ID: 5424344
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 28:9; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CYCLOTRON INSTABILITY
DOPPLER EFFECT
ELECTRON DRIFT
INSTABILITY
MAGNETIC FIELDS
MAGNETIC MIRRORS
MIRROR RATIO
OPEN PLASMA DEVICES
PLASMA
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
THERMONUCLEAR DEVICES
TRAPPING