The resistive inner layer code developed to solve the inner layer resistive MHD equations, using the new algorithm for solving coupled differential equations with singular solutions, was modified to include a spatially varying density profile within the inner layer. The results confirm that the analytic varying density model developed by Greene and Miller yields physically meaningful results over the full range of normalized growth rates, not just in the ideal limit where the analytic model is tractable. Provided care is taken to normalize the density profile so that the total mass within the inner layer is fixed, the dispersion curves are insensitive to the form of the density profile. Also, the calculations revealed that there are parameter regimes where the dispersion relations do not depend on certain key equilibrium parameters. This is being investigated further.
The inductive motor model has been implemented in the ONETWO transport code to simulate the slowing down of plasma toroidal rotation due to a magnetic error field as observed in resistive wall mode experiments. Initial results show that the model can qualitatively describe the reduction of plasma rotation. However, detailed features are not explained, which suggests that additional physics is needed to include in the model to fully describe the observed slowdown.
Disclaimer
These highlights are reports of research work in progress and are accordingly subject to change or modification