Fluid moment models for Landau damping with application to the ion-temperature-gradient instability

• Published in: Physical review letters Vol. 64; no. 25; pp. 3019 - 3022
• Main Authors: Hammett, GW, Perkins, FW
• Format: Journal Article
• Language: English
• Published: United States 18-06-1990
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 700107 - Fusion Energy- Plasma Research- Instabilities; DAMPING; DATA; DISPERSION RELATIONS; DISTRIBUTION FUNCTIONS; EQUATIONS; FUNCTIONS; INFORMATION; INSTABILITY; LANDAU DAMPING; NONLINEAR PROBLEMS; NUMERICAL DATA; PLASMA; PLASMA INSTABILITY; PLASMA MICROINSTABILITIES; RESPONSE FUNCTIONS; TEMPERATURE GRADIENTS; THEORETICAL DATA; TURBULENCE; USES
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.64.3019

A closed set of fluid moment equations is developed which represents kinetic Landau damping physics and which takes a simple form in wave-number space. The linear-response function corresponds to a three-pole (or four-pole) approximation to the plasma dispersion function {ital Z}. Alternatively, the response is exact for a distribution function which is close to Maxwellian, but which decreases asymptotically as 1/{ital v}{sup 4} (or 1/{ital v}{sup 6}). Among other applications, these equations should be useful for nonlinear studies of turbulence driven by the ion-temperature-gradient or other drift-wave microinstabilities.