Global gyrokinetic simulation of edge coherent mode in EAST. (1st February 2023)
- Record Type:
- Journal Article
- Title:
- Global gyrokinetic simulation of edge coherent mode in EAST. (1st February 2023)
- Main Title:
- Global gyrokinetic simulation of edge coherent mode in EAST
- Authors:
- Xie, Baoyi
Ye, Lei
Chen, Yang
Zhao, Pengfei
Ye, Yang
Lin, Xin
Lan, Heng
Guo, Wenfeng
Xiang, Nong - Abstract:
- Abstract: Linear and nonlinear simulations are carried out for the edge coherent mode (ECM) using the global gyrokinetic code GEM based on the EAST experimental parameters. The linear simulation results show that ECM is an electrostatic mode with dominant toroidal mode number n = 18 and frequency about 48 kHz, and propagates along the direction of electron diamagnetic drift, which are consistent with the experimental results. In addition, the density and electron temperature gradients destabilize the mode, while the collision stabilizes the mode. The nonlinear simulation results show that the saturated particle and heat fluxes induced by ECM are mainly due to the perturbed electrostatic ExB drift, and the fluxes of electrons and ions are almost equal. The ECM drives significant outward particle and heat fluxes, thus greatly promoting the maintenance of the long pulse H-mode. The Fourier decomposition of fluxes and potentials demonstrate that the intermediate- n modes of n = 14, 18 grow fastest in the linear phase, while in the nonlinear saturation phase, the low-n modes such as n = 4, 6 dominate and the fluxes are mainly contributed by the mode of n = 10. It is found that zonal flow is not the dominant saturation mechanism of the turbulence. The inverse spectral cascade of turbulence is inevitably observed in the nonlinear saturation process, indicating that it is a more universal turbulence saturation mechanism. It is also found that radial electric field can greatly reduceAbstract: Linear and nonlinear simulations are carried out for the edge coherent mode (ECM) using the global gyrokinetic code GEM based on the EAST experimental parameters. The linear simulation results show that ECM is an electrostatic mode with dominant toroidal mode number n = 18 and frequency about 48 kHz, and propagates along the direction of electron diamagnetic drift, which are consistent with the experimental results. In addition, the density and electron temperature gradients destabilize the mode, while the collision stabilizes the mode. The nonlinear simulation results show that the saturated particle and heat fluxes induced by ECM are mainly due to the perturbed electrostatic ExB drift, and the fluxes of electrons and ions are almost equal. The ECM drives significant outward particle and heat fluxes, thus greatly promoting the maintenance of the long pulse H-mode. The Fourier decomposition of fluxes and potentials demonstrate that the intermediate- n modes of n = 14, 18 grow fastest in the linear phase, while in the nonlinear saturation phase, the low-n modes such as n = 4, 6 dominate and the fluxes are mainly contributed by the mode of n = 10. It is found that zonal flow is not the dominant saturation mechanism of the turbulence. The inverse spectral cascade of turbulence is inevitably observed in the nonlinear saturation process, indicating that it is a more universal turbulence saturation mechanism. It is also found that radial electric field can greatly reduce the turbulence intensity and transport level. From the analyses of frequency and transport channels, it can be concluded that ECM appears to be the collisionless trapped electron mode. … (more)
- Is Part Of:
- Nuclear fusion. Volume 63:Number 2(2023)
- Journal:
- Nuclear fusion
- Issue:
- Volume 63:Number 2(2023)
- Issue Display:
- Volume 63, Issue 2 (2023)
- Year:
- 2023
- Volume:
- 63
- Issue:
- 2
- Issue Sort Value:
- 2023-0063-0002-0000
- Page Start:
- Page End:
- Publication Date:
- 2023-02-01
- Subjects:
- global gyrokinetic simulation -- edge coherent mode -- trapped electron mode -- turbulent transport -- zonal flow -- inverse spectral cascade
Nuclear fusion -- Periodicals
621.48405 - Journal URLs:
- http://www.iop.org/EJ/journal/0029-5515 ↗
http://iopscience.iop.org/0029-5515/ ↗
http://ioppublishing.org/ ↗ - DOI:
- 10.1088/1741-4326/acadf1 ↗
- Languages:
- English
- ISSNs:
- 0029-5515
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - BLDSS-3PM
British Library STI - ELD Digital store - Ingest File:
- 25637.xml