“Nontwist Magnetic Field Line Map in Tokamak with Ergodic Limiter and Safety Factor Profile: Formation of Degenerate Systems”

https://pubmed.ncbi.nlm.nih.gov/38115434

This study presents a nontwist magnetic field line map for a tokamak with an ergodic magnetic limiter and arbitrary safety factor profile, demonstrating the formation of degenerate systems like twin islands, shearless curves, and separatrix reconnection.