Stability of the Global Alfven Eigenmode in the presence of fusion alpha particles in an ignited tokamak plasma

Technical Report · Mon May 01 04:00:00 EDT 1989

DOI:https://doi.org/10.2172/5467703· OSTI ID:5467703

Fu, G. Y.; Van Dam, J. W. ^[1]

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1. Texas Univ., Austin, TX (USA). Inst. for Fusion Studies

The stability of the Global Alfven Eigenmodes is investigated in the presence of super-Alfvenic energetic particles, such as the fusion-product alpha particles in an ignited deuterium-tritium tokamak plasma. Alpha particles tend to destabilize these modes when {omega}{sub *{alpha}} > {omega}{sub A}, where {omega}{sub A} is the shear-Alfven modal frequency and {omega}{sub *{alpha}} is the alpha particle diamagnetic drift frequency. This destabilization due to alpha particles is found to be significantly enhanced when the alpha particles are modeled with a slowing-down distribution function rather than with a Maxwellian. However, previously neglected electron damping due to the magnetic curvature drift is found to be comparable in magnitude to the destabilizing alpha particle term. Furthermore, the effects of toroidicity are also found to be stabilizing, since the intrinsic toroidicity induces poloidal mode coupling, which enhances the parallel electron damping from the sideband shear-Alfven Landau resonance. In particular, for the parameters of the proposed Compact Ignition Tokamak, the Global Alfven Eigenmodes are found to be completely stabilized by either the electron damping that enters through the magnetic curvature drift or the damping introduced by finite toroidicity. 29 refs., 8 figs., 1 tab.

• Research Organization: Texas Univ., Austin, TX (USA). Inst. for Fusion Studies
• Sponsoring Organization: DOE/ER; TXAERF; TXATECH
• DOE Contract Number: FG05-80ET53088
• OSTI ID: 5467703
• Report Number(s): DOE/ET/53088-370; IFSR--370; ON: DE89016618
• 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
CLOSED PLASMA DEVICES
DAMPING
EQUILIBRIUM
FUNCTIONS
HYDROMAGNETIC WAVES
INSTABILITY
LANDAU DAMPING
MHD EQUILIBRIUM
PLASMA INSTABILITY
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
WAVE FUNCTIONS