Self-organized helical equilibria as a new paradigm for ohmically heated fusion plasmas

A reversed-field pinch is a toroidal device for magnetically confining plasmas, and a potential alternative to the tokamak for a future fusion reactor. Observations of the evolution of a reversed-field-pinch plasma towards a self-organized single-helicity state suggest that instability problems, which have previously hindered the development of these devices, could now be overcome.