Models for impurity effects in tokamaks

Technical Report · Sat Mar 01 00:00:00 EST 1980

DOI:https://doi.org/10.2172/5658884· OSTI ID:5658884

Hogan, J. T.

Models for impurity effects in tokamaks are described with an emphasis on the relationship between attainment of high ..beta.. and impurity problems. We briefly describe the status of attempts to employ neutral beam heating to achieve high ..beta.. in tokamaks and propose a qualitative model for the mechanism by which heavy metal impurities may be produced in the startup phase of the discharge. We then describe paradoxes in impurity diffusion theory and discuss possible resolutions in terms of the effects of large-scale islands and sawtooth oscillations. Finally, we examine the prospects for the Zakharov-Shafranov catastrophe (long time scale disintegration of FCT equilibria) in the context of present and near-term experimental capability.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5658884
• Report Number(s): ORNL/TM-7219; TRN: 80-007227
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
IMPURITIES
MATHEMATICAL MODELS
TOKAMAK DEVICES
BETA RATIO
FLUX CONSERVING TOKAMAKS
HIGH-BETA PLASMA
MAGNETIC ISLANDS
NEUTRAL ATOM BEAM INJECTION
SHEAR
BEAM INJECTION
CLOSED PLASMA DEVICES
MAGNETIC FIELD CONFIGURATIONS
PLASMA
THERMONUCLEAR DEVICES
700105* - Fusion Energy- Plasma Research- Plasma Kinetics-Theoretical- (-1987)