The effects of main-ion dilution on turbulence in low q95 C-Mod ohmic plasmas, and comparisons with nonlinear GYRO
Abstract
Recent experiments on C-mod seeding nitrogen into ohmic plasmas with q95 = 3.4 found that the seeding greatly reduced long-wavelength (ITG-scale) turbulence. The long-wavelength turbulence that was reduced by the nitrogen seeding was localized to the region of r/a ≈ 0.85, where the turbulence is well above marginal stability (as evidenced by Qi/QGB $$\gg$$ 1). The nonlinear gyrokinetic code GYRO was used to simulate the expected turbulence in these plasmas, and the simulated turbulent density fluctuations and turbulent energy fluxes quantitatively agreed with the experimental measurements both before and after the nitrogen seeding. Unexpectedly, the intrinsic rotation of the plasma was also found to be affected by the nitrogen seeding, in a manner apparently unrelated to a change in the electron-ion collisionality that was proposed by other experiments.
- Authors:
-
[3];
[1];
[1];
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
- General Atomics, San Diego, CA (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Publication Date:
- Research Org.:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- Contributing Org.:
- Alcator C-Mod Team
- OSTI Identifier:
- 1894488
- Alternate Identifier(s):
- OSTI ID: 1283415
- Grant/Contract Number:
- FC02-99ER54512; FG02-94ER54235; FC02-99-ER54512-CMOD; FG02-94-ER54235
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 23; Journal Issue: 8; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Plasma confinement; Leptons; Energy production, transmission and distribution; Plasma discharges; Energy flux; Chemical elements; Turbulence simulations; Control theory; Optical instruments; Fusion reactors
Citation Formats
Ennever, P., Porkolab, M., Candy, J., Staebler, G., Reinke, M. L., Rice, J. E., Rost, J. C., Ernst, D., Hughes, J., and Baek, S. G. The effects of main-ion dilution on turbulence in low q95 C-Mod ohmic plasmas, and comparisons with nonlinear GYRO. United States: N. p., 2016.
Web. doi:10.1063/1.4960315.
Ennever, P., Porkolab, M., Candy, J., Staebler, G., Reinke, M. L., Rice, J. E., Rost, J. C., Ernst, D., Hughes, J., & Baek, S. G. The effects of main-ion dilution on turbulence in low q95 C-Mod ohmic plasmas, and comparisons with nonlinear GYRO. United States. https://doi.org/10.1063/1.4960315
Ennever, P., Porkolab, M., Candy, J., Staebler, G., Reinke, M. L., Rice, J. E., Rost, J. C., Ernst, D., Hughes, J., and Baek, S. G. Fri .
"The effects of main-ion dilution on turbulence in low q95 C-Mod ohmic plasmas, and comparisons with nonlinear GYRO". United States. https://doi.org/10.1063/1.4960315. https://www.osti.gov/servlets/purl/1894488.
@article{osti_1894488,
title = {The effects of main-ion dilution on turbulence in low q95 C-Mod ohmic plasmas, and comparisons with nonlinear GYRO},
author = {Ennever, P. and Porkolab, M. and Candy, J. and Staebler, G. and Reinke, M. L. and Rice, J. E. and Rost, J. C. and Ernst, D. and Hughes, J. and Baek, S. G.},
abstractNote = {Recent experiments on C-mod seeding nitrogen into ohmic plasmas with q95 = 3.4 found that the seeding greatly reduced long-wavelength (ITG-scale) turbulence. The long-wavelength turbulence that was reduced by the nitrogen seeding was localized to the region of r/a ≈ 0.85, where the turbulence is well above marginal stability (as evidenced by Qi/QGB $\gg$ 1). The nonlinear gyrokinetic code GYRO was used to simulate the expected turbulence in these plasmas, and the simulated turbulent density fluctuations and turbulent energy fluxes quantitatively agreed with the experimental measurements both before and after the nitrogen seeding. Unexpectedly, the intrinsic rotation of the plasma was also found to be affected by the nitrogen seeding, in a manner apparently unrelated to a change in the electron-ion collisionality that was proposed by other experiments.},
doi = {10.1063/1.4960315},
journal = {Physics of Plasmas},
number = 8,
volume = 23,
place = {United States},
year = {Fri Aug 05 00:00:00 EDT 2016},
month = {Fri Aug 05 00:00:00 EDT 2016}
}
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Works referencing / citing this record:
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