Compressional Alfvin Eigenmode Dispersion in Low Aspect Ratio Plasmas
- Princeton Plasma Physics Laboratory
Recent observations of new fast ion beam driven instabilities in MHz frequency range in National Spherical Torus experiments (NSTX) are suggested to be Compressional Alfvin Eigenmodes (CAEs). A new theory of CAEs applicable to low aspect ratio toroidal plasmas is developed based on the ballooning representation for the poloidal dependence of the perturbed quantities. In agreement with observations, the analytical theory predicts that CAEs are discrete modes with frequencies correlated with the characteristic Alfvin velocity of the plasma. Plasma equilibrium structure is essential to determine accurately the dispersion of CAEs. The mode structure is localized in both the minor radius and the poloidal directions on the low magnetic field side.
- Research Organization:
- Princeton Plasma Physics Lab., NJ (US)
- Sponsoring Organization:
- USDOE Office of Science (US)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 795724
- Report Number(s):
- PPPL-3663.pdf
- Country of Publication:
- United States
- Language:
- English
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