Fast-Particle-Driven Alfvenic Modes in a Reversed Field Pinch

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.109.115003· OSTI ID:1055197

Koliner, J. J. ^[1]; Forest, C. B. ^[1]; Sarff, J. S. ^[1]; Anderson, J. ^[1]; Liu, D ^[1]; Nomberg, M. D. ^[1]; Waksman, J. ^[1]; Lin, L. ^[2]; Brower, D. L. ^[2]; Ding, W. X. ^[2]; Spong, Donald A ^[3]

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1. University of Wisconsin, Madison
2. University of California, Los Angeles
3. ORNL

Alfvenic modes are observed due to neutral beam injection for the first time in a reversed field pinch plasma. Modeling of the beam deposition and slowing down shows that the velocity and radial localization are high. This allows instability drive from inverse Landau damping of a bump-on-tail in the parallel distribution function or from free energy in the fast ion density gradient. Mode switching from a lower frequency toroidal mode number n = 5 mode that scales with beam injection velocity to a higher frequency n = 4 mode with Alfvenic scaling is observed.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1055197
• Journal Information: Physical Review Letters, Vol. 109, Issue 11; ISSN 0031--9007
• Country of Publication: United States
• Language: English