2024/11/20 by H. R. Strauss, Strauss, H. R. · 1 citation
Decision Sciences · Engineering · Health Professions · #Electrical Fault Detection and Protection #FOS: Physical sciences #Plasma Physics (physics.plasm-ph) #Quality and Safety in Healthcare #Risk and Safety Analysis
paper · pdf · doi:10.48550/arxiv.2411.13256
openalex publication_date 2024/11/20 · openalex created_date 2024/11/24 · openalex updated_date 2026/07/28
Resistive wall tearing modes (RWTM) can cause major disruptions. A signature of RWTMs is that the rational surface is sufficiently close to the wall. For (m,n) = (2,1) modes, at normalized minor radius ρ= 0.75, the value of q is q75 < 2. This is confirmed in simulations and theory and in a DIII-D locked mode disruption database. The q75 < 2 criterion is valid at high β as well as at low β. A very important feature of RWTMs is that they produce major disruptions only when the q75 < 2 criterion is satisfied. If it is not satisfied, or if the wall is ideally conducting, then the mode does not produce a major disruption, although it can produce a minor disruption. Feedback, or rotation of the mode at the wall by complex feedback, can emulate an ideal wall, preventing major disruptions. The q75 criterion is analyzed in a linear simulations, and a simple geometric model is given.