Microtearing Instabilities and Electron Thermal Transport in Low and High Collisionality NSTX Discharges

T, Rafiq; S, Kaye; W, Guttenfelder; J, Weiland; E, Schuster; J, Anderson; L, Luo

doi:10.11578/1814945

Title: Microtearing Instabilities and Electron Thermal Transport in Low and High Collisionality NSTX Discharges

Dataset
Other Related Research

Abstract

Microtearing mode (MTM) real frequency, growth rate, magnetic fluctuation amplitude and resulting electron thermal transport are studied in systematic NSTX scans of relevant plasma parameters. The dependency of the MTM real frequency and growth rate on plasma parameters, suitable for low and high collision NSTX discharges, is obtained by using the reduced MTM transport model [T. Rafiq, et al., Phys. Plasmas 23, 062507 (2016)]. The plasma parameter dependencies are compared and found to be consistent with the results obtained from MTM using the Gyrokinetic GYRO code. The scaling trend of collision frequency and plasma beta is found to be consistent with the global energy confinement trend observed in the NSTX experiment. The strength of the magnetic fluctuation is found to be consistent with the gyrokinetic estimate.In earlier studies, it was found that the version of the Multi-Mode (MM) anomalous transport model, which did not contain the effect of MTMs, provided an appropriate description of the electron temperature profiles in standard tokamak discharges and not in spherical tokamaks. When the MM model, which involves transport associated with MTMs, is incorporated in the TRANSP code and is used in the study of electron thermal transport in NSTX discharges, it is observed thatmore »« less

Authors:: T, Rafiq; S, Kaye; W, Guttenfelder; J, Weiland; E, Schuster; J, Anderson; L, Luo

Publication Date:: Fri Feb 19 00:00:00 EST 2021

DOE Contract Number:: AC02-09CH11466

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

Keywords:: magnetic confinement; microtearing; instabilities; tokamaks; turbulence and transport; fusion plasma technology;

OSTI Identifier:: 1814945

DOI:: https://doi.org/10.11578/1814945

Citation Formats


                    T, Rafiq, S, Kaye, W, Guttenfelder, J, Weiland, E, Schuster, J, Anderson, and L, Luo. Microtearing Instabilities and Electron Thermal Transport in Low and High Collisionality NSTX Discharges.  United States: N. p., 2021. 
        Web.  doi:10.11578/1814945.

Copy to clipboard


                    T, Rafiq, S, Kaye, W, Guttenfelder, J, Weiland, E, Schuster, J, Anderson, & L, Luo. Microtearing Instabilities and Electron Thermal Transport in Low and High Collisionality NSTX Discharges.  United States.  doi:https://doi.org/10.11578/1814945

Copy to clipboard


                    T, Rafiq, S, Kaye, W, Guttenfelder, J, Weiland, E, Schuster, J, Anderson, and L, Luo. 2021.  
"Microtearing Instabilities and Electron Thermal Transport in Low and High Collisionality NSTX Discharges".  United States.  doi:https://doi.org/10.11578/1814945.  https://www.osti.gov/servlets/purl/1814945. Pub date:Fri Feb 19 00:00:00 EST 2021

Copy to clipboard


                    
@article{osti_1814945,

  title        = {Microtearing Instabilities and Electron Thermal Transport in Low and High Collisionality NSTX Discharges},

  author       = {T, Rafiq and S, Kaye and W, Guttenfelder and J, Weiland and E, Schuster and J, Anderson and L, Luo},

  abstractNote = {Microtearing mode (MTM) real frequency, growth rate, magnetic fluctuation amplitude and resulting electron thermal transport are studied in systematic NSTX scans of relevant plasma parameters. The dependency of the MTM real frequency and growth rate on plasma parameters, suitable for low and high collision NSTX discharges, is obtained by using the reduced MTM transport model [T. Rafiq, et al., Phys. Plasmas 23, 062507 (2016)]. The plasma parameter dependencies are compared and found to be consistent with the results obtained from MTM using the Gyrokinetic GYRO code. The scaling trend of collision frequency and plasma beta is found to be consistent with the global energy confinement trend observed in the NSTX experiment. The strength of the magnetic fluctuation is found to be consistent with the gyrokinetic estimate.In earlier studies, it was found that the version of the Multi-Mode (MM) anomalous transport model, which did not contain the effect of MTMs, provided an appropriate description of the electron temperature profiles in standard tokamak discharges and not in spherical tokamaks. When the MM model, which involves transport associated with MTMs, is incorporated in the TRANSP code and is used in the study of electron thermal transport in NSTX discharges, it is observed that the agreement with the experimental electron temperature profile is substantially improved.},

  doi          = {10.11578/1814945},

  journal      = {},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {Fri Feb 19 00:00:00 EST 2021},

  month        = {Fri Feb 19 00:00:00 EST 2021}

}

Copy to clipboard

Dataset:

View Dataset

DOI: https://doi.org/10.11578/1814945

Save / Share:

Export Metadata

Save to My Library

Similar records in DOE Data Explorer and OSTI.GOV collections:

Microtearing instabilities and electron thermal transport in low and high collisionality NSTX discharges

Journal Article Rafiq, T. ; Kaye, S. ; Guttenfelder, W. ; ... - Physics of Plasmas

Microtearing mode (MTM) real frequency, growth rate, magnetic fluctuation amplitude, and resulting electron thermal transport are studied in systematic NSTX scans of relevant plasma parameters. The dependency of the MTM real frequency and growth rate on plasma parameters, suitable for low and high collision NSTX discharges, is obtained by using the reduced MTM transport model [T. Rafiq et al., Phys. Plasmas 23, 062507 (2016)]. The plasma parameter dependencies are compared and found to be consistent with the results obtained from MTM using the gyrokinetic GYRO code. The scaling trend of collision frequency and plasma beta is found to be consistentmore »« less
Microtearing instabilities and electron thermal transport in low and high collisionality NSTX discharges

Journal Article Rafiq, T. ; Kaye, S. ; Guttenfelder, W. ; ... - Physics of Plasmas

Microtearing mode (MTM) real frequency, growth rate, magnetic fluctuation amplitude, and resulting electron thermal transport are studied in systematic NSTX scans of relevant plasma parameters. The dependency of the MTM real frequency and growth rate on plasma parameters, suitable for low and high collision NSTX discharges, is obtained by using the reduced MTM transport model [T. Rafiq et al., Phys. Plasmas 23, 062507 (2016)]. The plasma parameter dependencies are compared and found to be consistent with the results obtained from MTM using the gyrokinetic GYRO code. The scaling trend of collision frequency and plasma beta is found to be consistentmore »« less
Linear ion-scale micro-stability analysis of high and low-collisionality NSTX discharges and NSTX-U projections

Dataset Clauser, Cesar ; Guttenfelder, Walter ; Rafiq, Tariq ; ...
Enhanced Pedestal H-mode at low edge ion collisionality on NSTX

Dataset Battaglia, D J ; Guttenfelder, W ; Bell, R E ; ...

The Enhanced Pedestal (EP) H-mode regime is an attractive wide-pedestal ELM-free high-betap scenario for NSTX-U and next-step devices as it achieves enhanced energy confinement (H98y,2 > 1.5), large normalized pressure (betaN > 5) and significant bootstrap fraction (f_BS > 0.6) at I_p/B_T = 2 MA/T. This regime is realized when the edge ion collisionality becomes sufficiently small that a positive feedback interaction occurs between a reduction in the ion neoclassical energy transport and an increase in the particle transport from pressure-driven edge instabilities. EP H-mode was most often observed as a transition following a large ELM in conditions with lowmore »« less
Microtearing Instabilities and Electron Transport in the NSTX Spherical Tokamak

Technical Report Wong, K. L. ; Kaye, S. ; Mikkelsen, D. R. ; ...

We report a successful quantitative account of the experimentally determined electron thermal conductivity χe in a beam-heated H mode plasma by the magnetic fluctuations from microtearing instabilities. The calculated χe based on existing nonlinear theory agrees with the result from transport analysis of the experimental data. Without using any adjustable parameter, the good agreement spans the entire region where there is a steep electron temperature gradient to drive the instability.

Similar Records