Electron Temperature Gradient Driven Transport Model for Tokamak Plasmas

Dataset · Fri Sep 02 00:00:00 EDT 2022

DOI:https://doi.org/10.11578/1888259· OSTI ID:1888259

Rafiq, Tariq; Wilson, Christopher; Luo, Lixiang; Weiland, Jan; Schuster, Eugenio; Pankin, Alexei; Guttenfelder, Walter; Kaye, Stan

A new model for electron temperature gradient (ETG) modes is developed as a component of the Multi-Mode anomalous transport module [T. Rafiq \textit{et al.,} Phys Plasmas \textbf{20}, 032506 (2013)] to predict a time dependent electron temperature profile in conventional and low aspect ratio tokamaks. This model is based on two-fluid equations that govern the dynamics of low-frequency short- and long-wavelength electromagnetic toroidal ETG driven drift modes. A low collisionality NSTX discharge is used to scan the plasma parameter dependence on the ETG real frequency, growth rate, and electron thermal diffusivity. Electron thermal transport is discovered in the deep core region where modes are more electromagnetic in nature. Several previously reported gyrokinetic trends are reproduced, including the dependencies of density gradients, magnetic shear, $$\beta$$ and gradient of $$\beta$$ $$(\betap)$$, collisionality, safety factor, and toroidicity, where $$\beta$$ is the ratio of plasma pressure to the magnetic pressure. The electron heat diffusivity associated with the ETG mode is discovered to be on a scale consistent with the experimental diffusivity determined by power balance analysis.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: SC0013977; SC0021385
• OSTI ID: 1888259
• Country of Publication: United States
• Language: English

Related Subjects

ETG
NSTX
Turbulence and transport
instabilities