From Single Helical relaxed states to helical equilibria

Abstract

This paper analyzes the relationship between the Single Helical relaxed states studied in R. Paccagnella, Phys. of Plasmas 23 (2016) 092512 and the so called 'helical ohmic equilibria', i.e. plasma states that are solutions of the helical Grad Shafranov equation and that satisfy the constraint imposed by the Ohm law. The existence of marginally stable helical equilibria is clearly demonstrated, while the ohmic constraint is not exactly satisfied within the proposed first order perturbation theory. The model predictions are however satisfactorily compared with experimental trends.