Issues in tokamak/stellarator transport and confinement enhancement mechanisms

Technical Report · Wed Aug 01 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/6681563· OSTI ID:6681563

Perkins, F W

At present, the mechanism for anomalous energy transport in low-{beta} toroidal plasmas -- tokamaks and stellarators -- remains unclear, although transport by turbulent E {times} B velocities associated with nonlinear, fine-scale microinstabilities is a leading candidate. This article discusses basic theoretical concepts of various transport and confinement enhancement mechanisms as well as experimental ramifications which would enable one to distinguish among them and hence identify a dominant transport mechanism. While many of the predictions of fine-scale turbulence are born out by experiment, notable contradictions exist. Projections of ignition margin rest both on the scaling properties of the confinement mechanism and on the criteria for entering enhanced confinement regimes. At present, the greatest uncertainties lie with the basis for scaling confinement enhancement criteria. A series of questions, to be answered by new experimental/theoretical work, is posed to resolve these outstanding contradictions (or refute the fine-scale turbulence model) and to establish confinement enhancement criteria. 73 refs., 4 figs., 5 tabs.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 6681563
• Report Number(s): PPPL-2708; ON: DE90014821; TRN: 90-025306
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
STELLARATORS
ENERGY TRANSPORT
TOKAMAK DEVICES
CONFINEMENT TIME
PLASMA CONFINEMENT
PLASMA MICROINSTABILITIES
POWER LOSSES
TURBULENCE
CLOSED PLASMA DEVICES
CONFINEMENT
ENERGY LOSSES
INSTABILITY
LOSSES
PLASMA INSTABILITY
THERMONUCLEAR DEVICES
700103* - Fusion Energy- Plasma Research- Kinetics