Speaker: Prof. Carl Sovinec, UW-Madison, Engineering Physics
Abstract: Full-scale operation of the ITER experiment will produce plasma thermal energy and releasable magnetic energy on the order of hundreds of mega-Joules. Unplanned disruptions to these discharges will be capable of causing significant material damage to plasma-facing components and structures. Efforts to understand disruptive dynamics, and to engineering mitigation systems, include the development of comprehensive numerical models that can make predictions without destructive testing. In this presentation, previous efforts for simulating different forms of disruption are reviewed, and a relatively recent effort, based on the NIMROD code (https://nimrodteam.org) is presented. We find that the modeling of heat flux at the domain boundary has more significance than the modeling of particle flux for the evolution of global parameters and for the longevity of the simulated discharge. Fully three-dimensional simulations show that surface contact enhances instabilities which develop near the plasma surface, and these asymmetries lead to net horizontal forcing on the chamber wall. These results also highlight the importance of physical effects at the boundary of the modeled region. Plans for including more realistic boundary effects are discussed.