Microinstability properties of small-aspect-ratio tokamaks
- Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543-0451 (United States)
Advanced tokamak configurations can have improved stability properties for high-{ital n} microinstabilities such as the toroidal drift mode (trapped-electron-{eta}{sub {ital i}} mode) and the kinetically-calculated magnetohydrodynamic (MHD) ballooning mode. A promising means to achieve this end involves employing tokamak configurations with very small aspect ratio, as in the proposed National Spherical Tokamak Experiment (NSTX) [M. Ono {ital et} {ital al}., Bull. Am. Phys. Soc. {bold 40}, 1655 (1995)] or the existing Small Tight Aspect Ratio Tokamak (START) experiment [R. J. Colchin {ital et} {ital al}., Phys. Fluids B {bold 5}, 2481 (1993)]. Kinetic instabilities are analyzed here using a comprehensive toroidal eigenvalue code with realistic equilibria for cases based on NSTX and START along with artificial cases to study parametric sensitivities. It is found that, as the aspect ratio decreases, the amount of {open_quote}{open_quote}bad{close_quote}{close_quote} magnetic curvature decreases, causing stabilization of both electrostatic and electromagnetic high-{ital n} instabilities at sufficiently small aspect ratio. {copyright} {ital 1996 American Institute of Physics.}
- Research Organization:
- Princeton Plasma Physics Laboratory
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 283356
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geometrical influences on neoclassical magnetohydrodynamic tearing modes
Excitation of toroidally localized harmonics of global Alfvén eigenmodes