Beam ion driven instabilities in the National Spherical Tokamak Experiment

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

22

Macroinstabilities, Magnetohydrodynamic Waves, Magnetohydrodynamics, Plasma Heating By Particle Beams, Tokamaks, Spherical Tokamaks, Fueling, Heating And Ignition, Safety, Magnetohydrodynamic And Fluid Equation, Plasma Kinetic Equations

Scientific paper

Recent progress in the analysis of the low and high frequency beam ion driven instabilities in the National Spherical Tokamak Experiment (NSTX) [S. Kaye et al., Fusion Technol. 36, 16 (1999)] plasma is reported. The low Alfvén speed with respect to the beam ion injection velocity in NSTX offers a window in the plasma parameter space to study instabilities driven by super-Alfvénic fusion alphas, which are expected in the International Tokamak Experimental Reactor-ITER [D. J. Campbell, Phys. Plasmas 8, 2041 (2001)]. Low frequency magnetic field activities identified as an instability of toroidicity-induced Alfvén eigenmodes (TAEs) have been observed in NSTX and analyzed with the linear hybrid kinetic magnetohydrodynamic stability code NOVA-K [C. Z. Cheng, Phys. Rep. 1, 211 (1992)]. The comparison between the TAE analysis and observations in NSTX and DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] similarity experiments confirms that the toroidal mode number of the most unstable TAE modes scales with q-2 and is independent of plasma major radius, where q is the safety factor. This scaling helps validate the predictive capability of the NOVA-K code for studying TAE stability in future burning plasma devices. The subion cyclotron frequency magnetic activities in NSTX are identified as compressional and global shear Alfvén eigenmodes (AEs) (CAEs and GAEs). CAE and GAE instabilities are driven by beam ions via the Doppler shifted cyclotron resonance by the velocity space bump-on-tail distribution function in the perpendicular velocity. Results of the GAE/CAE theoretical and numerical analysis are presented.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Beam ion driven instabilities in the National Spherical Tokamak Experiment does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Beam ion driven instabilities in the National Spherical Tokamak Experiment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Beam ion driven instabilities in the National Spherical Tokamak Experiment will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1552643

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.