Analysis of Dependence of Transport Coefficients on Safety Factor Profile in DIII-D

We have expanded previous work [Mordijck NF 2020] on the dependence of plasma transport coefficients on collisionality to analyze dependence on safety factor profile, q, by examining shots over a range of q₉₅. Future fusion devices will have edge pedestals that will ionize neutrals outside of the separatrix [Romanelli NF 2015], meaning these pedestals will be dominated by charged particle and heat transport. Gas puff modulation is a common method to extract perturbed transport coefficients. Curvature pinch transport is linked to the gradient of q(r), motivating our investigation. This technique is well established for the core but allowing the source term of the particle balance equation to vary and optimizing our fitted transport profile with the source included extends our analysis to the edge. Future work could also include Lyman-alpha diagnostics for absolute edge source measurements. Currently, we are developing a self-consistent set of tools to extract transport coefficients from a wider range of data to advance understanding of transport dependence on various parameters. Future work can apply these tools to develop predictive transport modelling, and extend to comparison of models with non-modulated shots.