Finite Larmor radius stability theory of ELMO Bumpy Torus plasmas

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.864456· OSTI ID:5880308

Berk, H L; Cheng, C Z; Rosenbluth, M N; Van Dam, J W

An eikonal ballooning mode formalism is developed to describe curvature-driven modes of hot electron plasmas in bumpy tori. The formalism treats frequencies comparable to the ion cyclotron frequency, as well as arbitrary finite Larmor radius and field polarization, although the detailed analysis is restricted to E/sub parallel/ = 0. Moderate hot electron finite Larmor radius effects are found to lower the background beta core limit, whereas strong finite Larmor radius effects produce stabilization. The critical finite Larmor radius parameter with weak curvature is FR = k/sup 2//sub perpendicular/ rho/sup 2//sub h/R/ ..delta../sub b/ (1+P/sup prime//sub parallel// P/sup //sub perpendicular/) where k/sub perpendicular/ is the perpendicular wavenumber, rho/sub h/ the hot electron Larmor radius, R the magnetic field radius of curvature at the hot-electron layer, ..delta../sub b/ the magnetic field scale length in the diamagnetic well, and P/sup prime//sub parallel,perpendicular/ are the parallel and perpendicular pressure gradients. The interchange instability arises if 1>FR>1-..beta../sub c/R/ (2..delta..(1+P/sup //sub parallel//P/sup prime//sub perpendicular/)), whereas all modes are stable if FR>1, where ..beta../sub c/ is the core plasma beta and ..delta.. is the core plasma pressure gradient length.

• Research Organization: Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712
• DOE Contract Number: FG05-80ET53088
• OSTI ID: 5880308
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 26:9; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
700108 -- Fusion Energy-- Plasma Research-- Wave Phenomena
ALFVEN WAVES
BALLOONING INSTABILITY
ELMO BUMPY TORUS
ELMO DEVICES
HOT PLASMA
HYDROMAGNETIC WAVES
INSTABILITY
LARMOR RADIUS
MAGNETIC FIELDS
MAGNETIC MIRRORS
OPEN PLASMA DEVICES
OPERATION
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
STABILITY
THERMONUCLEAR DEVICES