Rl. Viana et Db. Vasconcelos, FIELD-LINE STOCHASTICITY IN A TOKAMAK WITH AN ERGODIC MAGNETIC LIMITER, Dynamics and stability of systems, 12(2), 1997, pp. 75-88
We estimate the threshold value of the perturbation strength needed to
cause magnetic field-line stochasticity in the peripheral region of a
Tokamak with an ergodic magnetic limiter, accoriding to a Hamiltonian
description for field lines. We model the limiter action as a periodi
c sequence of impulsive excitations. Two global stochasticity prescrip
tions are used: Chirikov's overlapping criterion and the renormalizati
on scheme of Escande, Doveil and Benkadda.