Influence of rotation on axisymmetric plasma equilibria: double-null DTT scenario

Abstract

Abstract We study the influence of toroidal plasma rotation on some relevant tokamak equilibrium quantities. The Grad–Shafranov equation generalised to the rotating case is analytically solved employing two different representations for the homogenous solution. Using an expression in terms of polynomials, we describe the separatrix shape by a few geometrical parameters, reproducing different plasma scenarios such as double-null and inverse triangularity. In this setting, the introduction of toroidal rotation corresponds to variations on relevant plasma quantities, most notably an enhancement of the poloidal beta. Using a more general expression in terms of Bessel functions, we reconstruct the full plasma boundary of the double-null configuration proposed for the upcoming Divertor Tokamak Test experiment, demonstrating how said configuration is compatible with different values of the plasma velocity.