Alpha particle driven Alfven wave instability in a tandem mirror reactor

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5002143

Hanson, J D

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 anisotrophy 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. In a typical fusion plasma (central ion temperature T/sub io/ = 20 keV, central electron temperature T/sub eo/ = 20 keV, central beta ..beta../sub c/ = 0.4, vacuum magnetic field B/sub v/ = 3T) we find 60% of the alpha particle energy is lost when the effects of the instability are included, whereas only 17% is lost without the instability.

• Research Organization: Maryland Univ., College Park (USA)
• OSTI ID: 5002143
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ALFVEN WAVES
ALPHA PARTICLES
CHARGED PARTICLES
CYCLOTRON RESONANCE
DISTRIBUTION FUNCTIONS
FUNCTIONS
HYDROMAGNETIC WAVES
INSTABILITY
MAGNETIC MIRROR TYPE REACTORS
PLASMA INSTABILITY
PLUGGING
RESONANCE
THERMONUCLEAR REACTORS
TMR REACTORS