TMX-U thermal-barrier experiments

Journal Article · Mon Feb 01 00:00:00 EST 1988 · IEEE Trans. Plasma Sci.; (United States)

DOI:https://doi.org/10.1109/27.3782· OSTI ID:5041398

Simonen, T C; Allen, S L; Barter, J D; Casper, T A; Correll, D L; Carter, M R; Clauser, J F; Dimonte, G; Foote, J H; Futch, A H

This review of thermal-barrier experiments in the Tandem Mirror Experiment Upgrade (TMX-U) describes our progress at Lawrence Livermore National Laboratory in plasma confinement and central-cell heating. Thermal barriers in TMX-U improved axial confinement by two orders of magnitude over a limited range of densities, compared with confinement in single-cell mirrors at the same ion temperature. Our study shows that central-cell radial nonambipolar confinement scales as neoclassical theory and can be eliminated by floating the end walls. Radial ambipolar losses can also be measured and reduced. The electron energy balance is improved in tandem mirrors to near classical, resulting in T/sub e/ up to 0.28 keV. Electron cyclotron heating (ECH) efficiencies up to 42 percent, with low levels of electron microinstability, were achieved when hot electrons in the thermal barrier were heated to average betas as large as 15 percent. The hot-electron distribution is measured from X rays and is modeled by a Fokker-Planck code that includes heating from cavity radio-frequency (RF) fields. Neutral-beam injection in the central cell created average ion betas up to 5 percent with radial profiles of hot ions that are modeled accurately by a radial Fokker-Planck code. Gas fueling between two fundamental ion cyclotron heating (ICH) resonances resulted in symmetrical heating of passing ions toward both ends.

• Research Organization: Lawrence Livermore National Lab., Univ. of California, Livermore, CA (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5041398
• Journal Information: IEEE Trans. Plasma Sci.; (United States), Journal Name: IEEE Trans. Plasma Sci.; (United States) Vol. 16:1; ISSN ITPSB
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700208* -- Fusion Power Plant Technology-- Inertial Confinement Technology
BENCH-SCALE EXPERIMENTS
CONFINEMENT
DISTRIBUTION FUNCTIONS
EFFICIENCY
ELECTRONS
ELEMENTARY PARTICLES
ENERGY BALANCE
FERMIONS
FUNCTIONS
LAWRENCE LIVERMORE LABORATORY
LEPTONS
MAGNETIC MIRRORS
NATIONAL ORGANIZATIONS
OPEN PLASMA DEVICES
PLASMA
PLASMA CONFINEMENT
TANDEM MIRRORS
THERMAL BARRIERS
THERMAL EFFICIENCY
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TMX DEVICES
US AEC
US DOE
US ERDA
US ORGANIZATIONS