Nonlinear saturation of the turbulent alpha effect

We study the saturation of the turbulent alpha effect in the nonlinear regime. A numerical experiment is constructed based on thr full nonlinear magnetohydrodynamics equations that allows the alpha effect to be measured for different values of the mean magnetic field. rile object is to distinguish between two possible theories of nonlinear saturation. It is found that the results are in close agreement with the theories that predict strong suppression and are incompatible with those that predict that the turbulent alpha effect persists up to mean fields of order of the equipartition energy.