Abstract Details
Abstracts
Author: Kemal Atay
Requested Type: Poster
Submitted: 2026-03-19 20:38:01
Co-authors: M.J. Pueschel, P.W. Terry, T. Jitsuk
Contact Info:
University of Wisconsin-Madison
1150 University Ave
Madison, WI 53706
United States
Abstract Text:
Multiscale gyrokinetic simulations are important in understanding the full behavior of turbulence in magnetically confined plasmas. In reversed-field pinch (RFP) plasmas, the gyrokinetic code GENE is used to model the linear behavior of tearing modes and drift waves, and in the nonlinear regime, their interactions over the multiple scales that separate them. In an RFP equilibrium, the toroidal field typically reverses sign. The mapping between the toroidal flux and the radius is double valued. Since the toroidal field is often used to label magnetic flux surfaces and enters into quantities employed in coordinate definitions and magnetic-field characterization, changes to the framework may be needed to treat radial regions that include the reversal surface where the field crosses zero. Indeed, calculation of linear mode behavior close to the reversal surface using GENE results in the need for very small time steps as wavenumbers become smaller. This leaves gaps in data. In this work, we introduce such changes to the GENE code and perform tests for linear flux-tube simulations that include the reversal surface continuously across a range of wavenumbers. Furthermore, we run nonlinear local simulations over this region to analyze turbulent states. These results are compared against global simulations covering the reversal surface, in preparation of global tearing and microturbulence simulations spanning most of the device.
Characterization: 4.0
Comments: