We report the first direct measurement of the internal magnetic field structure associated with a 3D helical equilibrium generated spontaneously in the core of an axisymmetric toroidal plasma containment device. Magnetohydrodynamic equilibrium bifurcation occurs in a reversed-field pinch when the innermost resonant magnetic perturbation grows to a large amplitude, reaching up to 8% of the mean field strength. Magnetic topology evolution is determined by measuring the Faraday effect, revealing that, as the perturbation grows, toroidal symmetry is broken and a helical equilibrium is established. © 2011 American Physical Society.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
Bergerson, W. F., Auriemma, F., Chapman, B. E., Ding, W. X., Zanca, P., Brower, D. L., ... Terranova, D. (2011). Bifurcation to 3D helical magnetic equilibrium in an axisymmetric toroidal device. Physical Review Letters, 107(25), -. . https://doi.org/10.1103/PhysRevLett.107.255001