Alpha-particle-driven Alfven wave instability in a tandem mirror reactor

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Phys. Fluids; (United States)

OSTI ID:5508101

Hanson, J D; Ott, E

Because their energies greatly exceed the plug potential, fusion reaction alpha particles in a tandem mirror reactor will be mirror confined rather than electrostatically confined by the end plugs. Hence, the alpha particle distribution function will have a loss cone. This anisotropy in the distribution function is shown to destabilize Alfven waves in the central section of a tandem mirror reactor. The wave equation with a modified cold plasma response is used to determine the radial mode structure and real frequency of the Alfven waves in cylindrical geometry. The growth rate is calculated from the resonant particle part of the plasma response. Destabilization of the wave occurs due to a cyclotron resonance of the alpha particles. The resonant interaction of the wave with the alpha particles will pitch-angle scatter the alphas into the loss cone, effectively widening the loss cone. The instability will cause a substantial loss of alpha particle energy unless the central cell is characterized by small diameter, sharply peaked radial profile, low magnetic field, and large mirror ratio. A recent ''axicell'' reactor design is found to be stable.

• Research Organization: Laboratory for Plasma and Fusion Energy Studies, University of Maryland, College Park, Maryland 20742
• OSTI ID: 5508101
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 27:1; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700107* -- Fusion Energy-- Plasma Research-- Instabilities
700108 -- Fusion Energy-- Plasma Research-- Wave Phenomena
ALFVEN WAVES
ALPHA PARTICLES
CHARGED PARTICLES
CONFIGURATION
CYCLOTRON RESONANCE
CYLINDRICAL CONFIGURATION
DIFFERENTIAL EQUATIONS
EQUATIONS
HYDROMAGNETIC WAVES
INSTABILITY
INSTABILITY GROWTH RATES
LOSS CONE
MAGNETIC MIRROR TYPE REACTORS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
PLASMA INSTABILITY
RESONANCE
STABILITY
THERMONUCLEAR REACTORS
TMR REACTORS
WAVE EQUATIONS