An alpha loss-cone instability in the central cell of a tandem mirror reactor

Technical Report · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6458406

Ho, Shu Kay

D-T fusion-born alpha particles are mirror-confined in the central cell of a tandem mirror reactor. The resulting anisotropic loss-cone distribution of the alpha particles in velocity space is capable of destabilizing low frequency plasma waves, thus affecting the energy balance in a tandem mirror plasma. The low frequency waves of a cold, cylindrical, sharp-boundary, D-T plasma are studied. Techniques have been developed to trace the wave propagation regions and search the wave eigenfrequencies. Three branches of waves are found, namely the Alfven, hybrid, and fast waves; but only the Alfven wave is destabilized by the alpha loss-cone instability. The modeling of the alpha distribution function for the linear and quasi-linear instability calculations is done by a diffusion-front method and a numerical finite difference method, respectively. Their validity is established by comparing them with a converged 80-term Legendre function expansion model of the alpha distribution. The growth rate of the instability is basically determined by the alpha number density, the loss-cone angle, and the polarization of the wave. These quantities are in turn mainly affected by the density and temperature of the plasma ions and electrons, the mirror ratio, and the plasma radius. 83 refs., 58 figs.

• Research Organization: Illinois Univ., Urbana (USA). Fusion Studies Lab.
• DOE Contract Number: FG02-86ER52127
• OSTI ID: 6458406
• Report Number(s): DOE/ER/52127-12; ON: DE87011044
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ALFVEN WAVES
ALPHA PARTICLES
CHARGED PARTICLES
D-T REACTORS
ELECTRON DENSITY
ELECTRON TEMPERATURE
FUNCTIONS
HYDROMAGNETIC WAVES
INSTABILITY
ION DENSITY
ION TEMPERATURE
LEGENDRE POLYNOMIALS
LOSS CONE INSTABILITY
MAGNETIC MIRROR TYPE REACTORS
MATHEMATICAL MODELS
MATHEMATICS
MIRROR RATIO
NUMERICAL ANALYSIS
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA WAVES
POLYNOMIALS
SCATTERING
THERMONUCLEAR REACTORS
TMR REACTORS