Relationship between onset thresholds, trigger types and rotation shear for them/n= 2/1 neoclassical tearing mode in a high-β spherical torus

S.P. Gerhardt, D.P. Brennan, R. Buttery, R.J. La Haye, S. Sabbagh, E. Strait, M. Bell, R. Bell, E. Fredrickson, D. Gates, B. LeBlanc, J. Menard (+3 others)
2009 Nuclear Fusion  
The onset conditions for the m/n=2/1 neoclassical tearing mode (NTM) are studied in terms of neoclassical drive, triggering instabilities, and toroidal rotation or rotation shear, in the spherical torus NSTX [M. Ono, et al., Nuclear Fusion 40, 557 (2000)]. There are three typical onset conditions for these modes, given in order of increasing neoclassical drive required for mode onset: triggering by energetic particle modes, triggering by edge localized modes, and cases where the modes appear to
more » ... the modes appear to grow without a trigger. In all cases, the required drive increases with toroidal rotation shear, implying a stabilizing effect from the shear.
doi:10.1088/0029-5515/49/3/032003 fatcat:z3rz75ivebeo7czxj4exrswspq