Fractional resonances between waves and energetic particles in tokamak plasmas
- Author(s): Kramer, GJ
- Chen, L
- Fisher, RK
- Heidbrink, WW
- Nazikian, R
- Pace, DC
- Van Zeeland, MA
- et al.
Published Web Locationhttps://doi.org/10.1103/PhysRevLett.109.035003
From numerical simulation and analytical modeling it is shown that fast ions can resonate with plasma waves at fractional values of the particle drift-orbit transit frequency when the plasma wave amplitude is sufficiently large. The fractional resonances, which are caused by a nonlinear interaction between the particle orbit and the wave, give rise to an increased density of resonances in phase space which reduces the threshold for stochastic transport. The effects of the fractional resonances on spatial and energy transport are illustrated for an energetic particle geodesic acoustic mode but they apply equally well to other types of MHD activity. © 2012 American Physical Society.
Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.