Faculty Mentor(s)
Dr. Zachary Williams, Physics
Document Type
Poster
Event Date
4-12-2024
Abstract
Reversed-Field Pinches (RFPs) operating in the Quasi-Single-Helicity (QSH) magnetic geometry exhibit significant improvements in confinement time as compared to standard discharges due to the efficient saturation of large-scale tearing modes. This modification to the magnetic geometry and profiles introduces new instabilities which drive transport. This work focuses on diagnosing the microinstabilities and microturbulence in a non-reversed Madison Symmetric Torus QSH experiment. Local gyrokinetic simulations are conducted with the GENE code to identify the dominant instabilities as ion-temperature-gradient (ITG) and density-gradient-driven trapped-electron-mode (TEM) at core and edge radial locations, respectively. It has been previously observed in the RFP (Williams PoP 2017) that residual tearing fluctuations in RFPs degrade zonal flows; the degree to which this affected turbulence and transport in that work depended on the driving instability. While initial investigations reveal strong zonal flow activity, an ad-hoc magnetic perturbation is employed to model magnetic fluctuations present in the RFP. These fluctuations degrade the zonal flow structure, resulting in a more substantial increase in electrostatic fluxes for the TEM-dominated position than for its ITG counterpart.
Recommended Citation
Repository citation: Kaipainen, Nicholas J.; De Jong, Y. L.; Helder, L.; Pueschel, M. J.; Sarff, J. S.; Terry, P. W.; and VanMeter, P. D., "Turbulence and Zonal-Flow Impact in the Madison Symmetric Torus in Quasi-Single Helicity" (2024). 23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024). Paper 45.
https://digitalcommons.hope.edu/curca_23/45
April 12, 2024. Copyright © 2024 Hope College, Holland, Michigan.
Comments
This work used the Dutch national e-infrastructure with the support of the SURF Cooperative using grant no. EINF-4067. This work was also supported via computational resources provided by the ACCESS Explore allocation PHY2300068, as well as the Jobe and Julia Morrison Family Faculty Development Fund.
Additional authors appear on poster that are not listed in the abstract booklet: Y. L. De Jong (Eindhoven University of Technology), L. Helder (Utrecht University), M. J. Pueschel (Dutch Institute for Fundamental Energy Research), J. S. Sarff (University of Wisconsin Madison), P. W. Terry (University of Wisconsin Madison), and P. D. VanMeter (University of Wisconsin Madison).