Turnstiles and Topological Index in Fusion Reactor Divertors

This lecture explores the mathematical analysis of magnetic field topology in fusion reactor divertors, focusing on turnstiles and topological indices. Discover how 'x'-points create diversion of field lines to increase separation between plasma and wall in fusion reactors. Learn about a numerical algorithm that evaluates turnstile area directly from stellarator coil solutions using Meiss's action principle. Examine how magnetic topology and chaos can be controlled in reactor edges through analysis of configurations from the QUASR database with novel divertor topologies. Understand how turnstile mechanisms create complex features in connection length plots used for divertor heat load analysis in W7-X low-iota configurations. Explore optimization results for W7-X and other configurations where fixed-point topology and stochasticity in the divertor region are controlled.