The Dynamic Ergodic Divertor (DED) is under construction as a novel tool for TEXTOR-94 to control transport at the plasma edge and possiblyalso plasma rotation. The DED has been laid out for the plasma reference conditions rres(q = 3) and βpol = 1. The operational space of DED is analysed here. It has been shown that a sufficient edge ergodization can be reached for all relevant βpol values (0 ⩽ βpol ⩽ 2). By shifting the resonance layer close tothe edge, the degree of ergodization can be substantially increased (by abouta factor of 4). The power supplies allow a superposition of the base n = 4mode with the n = 2 mode at arbitrary amplitude ratios, providing a partialdecoupling of the perturbation amplitude and its penetration; by an admixtureof 20% of the n = 2 mode, the diffusion coefficient for the magnetic fieldlines is significantly increased. Analyses of the operational space arecarried out by using both novel asymptotic and mapping methods.
Reflectometry measurements during operation of the dynamic ergodic divertor at TEXTOR