Cooper, W. A.Graves, J. P.Reimerdes, H.Sauter, O.Albergante, M.Brunetti, D.Halpern, F.Pfefferlé, D.Rossel, J.Pochelon, A.Coda, S.Duval, B. P.Labit, B.Chapman, I. T.Turnbull, A. D.Evans, T. E.Lao, L.Buttery, R.Ferron, J. R.Hollman, E.Petty, C.van Zeeland, M.Lazarus, E. A.Turco, F.Hanson, J.Fernstermacher, M. E.Lanctot, M. J.Cole, A. J.Jardin, S. C.Tobias, B. J.2012-11-152012-11-152012-11-152012https://infoscience.epfl.ch/handle/20.500.14299/86895Tokamaks with weak to moderate reversed central shear in which the minimum rotational transform $q_{min}$ is in the neighbourhood of unity can trigger bifurcated MagnetoHydrodynamic (MHD) equilibrium states, one of which is similar to a saturated ideal internak kink mode. Peaked prescribed pressure profiles reproduce the ``snake'' structures observed in many tokamaks which has led to a novel explanation of the snake as a bifurcated equilibrium state.Snake equilibrium structures are computed in simulations of the TCV, DIII-D and MAST tokamaks. The internal helical deformations only weakly modulate the plasma-vacuum interface which is more sensitive to ripple and resonant magnetic perturbations. On the other hand, the external perturbations do not alter the helical core deformation in a significant manner. The confinement of fast particles in MAST simulations deteriorate with the amplitude of the helical core distortion. These three-dimensional bifurcated solutions constitute a paradigm shift that motivates the applications of tools developed for stellarator research in tokamak physics investigations.Equlibriumbifurcationhelicaltext::conference output::conference proceedings::conference paper