Ian Stewart

Postdoctoral Fellow

Ian is a postdoctoral research scientist in plasma physics, who earned his PhD from Columbia University in 2021. His PhD research focused on experimental analysis of turbulence and transport processes in tokamaks, focusing on H-mode (high-confinement mode) physics in the HBT-EP experiment. H-mode is an attractive regime of tokamak operation, in which the turbulence and turbulent transport at the edge of the plasma are suppressed by strongly sheared flows. This reduction of heat and particle transport increases the pressure profile and the confinement time, leading to high performance plasmas. His dissertation research centered on understanding turbulence suppression by sheared flows and the generation of the strong flows which cause the L-H (low to high confinement) transition.

Joining the Paz-Soldan research group in 2021, Ian's postdoctoral research focuses on equilibrium reconstruction sensitivity studies on the future SPARC tokamak. In particular, the design and optimization of the in-vessel magnetic sensor layout for robust reconstruction of the plasma equilibrium is needed for the successful operation of the future fusion device. This includes the ability to accurately reconstruct the equilibrium with various experimental complications, such as sensor noise and eddy currents in the conducting structures.