Validation of NSFsim as a Grad-Shafranov equilibrium solver at DIII-D

Clark, Randall; Nurgaliev, Maxim; Khairutdinov, Eduard; Subbotin, Georgy; Welander, Anders; Orlov, Dmitri M.

doi:10.1016/j.fusengdes.2024.114765

Validation of NSFsim as a Grad-Shafranov equilibrium solver at DIII-D

Journal Article · Mon Dec 16 00:00:00 EST 2024 · Fusion Engineering and Design

DOI:https://doi.org/10.1016/j.fusengdes.2024.114765· OSTI ID:2483889

^[1]; ^[2]; ^[2]; ^[2]; Welander, Anders ^[3]; ^[1]

University of California San Diego, La Jolla, CA (United States)
Next Step Fusion S.a.r.l. (Luxembourg)
General Atomics, San Diego, CA (United States)

Plasma shape is a significant factor that must be considered for any Fusion Pilot Plant (FPP) as it has significant consequences for plasma stability and core confinement. A new simulator, NSFsim, has been developed based on a historically successful code, DINA [1], offering tools to simulate both transport and plasma shape. Specifically, NSFsim is a free boundary equilibrium and transport solver and has been configured to match the properties of the DIII-D tokamak. This paper is focused on validating the Grad-Shafranov (GS) solver of NSFsim by analyzing its ability to recreate the plasma shape, the poloidal flux distribution, and the measurements of the simulated diagnostic signals originating from flux loops and magnetic probes in DIII-D. Five different plasma shapes are simulated to show the robustness of NSFsim to different plasma conditions; these shapes are Lower Single Null (LSN), Upper Single Null (USN), Double Null (DN), Inner Wall Limited (IWL), and Negative Triangularity (NT). The NSFsim results are compared against real measured signals, magnetic profile fits from EFIT [2], and another plasma equilibrium simulator, GSevolve [3]. EFIT reconstructions of shots are readily available at DIII-D, but GSevolve was manually ran by us to provide simulation data to compare against.

View Accepted Manuscript (DOE)

Research Organization:: General Atomics, San Diego, CA (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Grant/Contract Number:: FC02-04ER54698

OSTI ID:: 2483889

Journal Information:: Fusion Engineering and Design, Journal Name: Fusion Engineering and Design Vol. 211; ISSN 0920-3796

Publisher:: ElsevierCopyright Statement

Country of Publication:: United States

Language:: English

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