ECEI characterization of pedestal fluctuations in quiescent H-mode plasmas in DIII-D

Yu, Guangyang; Nazikian, R.; Zhu, Yilun; Zheng, Yuan; Kramer, G. J.; Diallo, A.; Li, Zeyu; Chen, Xi; Ernst, D. R.; Yan, Z.; Austin, M. E.; Luhmann, Neville C.

doi:10.1088/1361-6587/ac7ee7

Cited by 9 publications

(2 citation statements)

References 54 publications

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“…This makes the electron temperature measured by ECEI appear higher than its actual value [2]. The signal intensity received by antenna at the electron cyclotron frequency and its harmonics is [9,[18][19][20][21]:…”

Section: I(ω)mentioning

confidence: 99%

A synthetic diagnostics platform for microwave imaging diagnostics in tokamaks

LI 李,

YANG 杨,

XU 徐

et al. 2024

Plasma Sci. Technol.

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Interpreting experimental diagnostics data in tokamaks, which accounts for non-ideal effects, is challenging due to the complexity of plasmas. To address this challenge, a general synthetic diagnostics (GSD) platform that serves for microwave imaging reflectometer (MIR) and electron cyclotron emission imaging (ECEI) has been established. This platform utilizes plasma profiles as input, and it incorporates finite difference time domain (FDTD), ray-tracing and radiative transfer equation to calculate the propagation of plasma spontaneous radiation and external electromagnetic field in plasmas. Benchmarks of classic cases have been conducted to verify the accuracy of every core module in GSD platform. Finally, a 2D imaging of a typical electron temperature distribution is reproduced by this platform and is consistent with the given real experimental data. This platform also has potential to be extended to 3D electromagnetic field simulations and to other microwave diagnostics such as cross-polarization scattering.

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Section: I(ω)mentioning

confidence: 99%

A synthetic diagnostics platform for microwave imaging diagnostics in tokamaks

LI 李,

YANG 杨,

XU 徐

et al. 2024

Plasma Sci. Technol.

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show abstract

“…The roll-over is often explained by a power or recombination particle sink [25] such that an overestimated ionization source can skew the particle balance. This might be overcome by the addition of molecular recombination losses in the particle balance as molecular recombination rates are relevant at higher temperatures overtaking the ionization source at higher temperatures, initiating the roll-over at lower upstream densities [25,[27][28][29].…”

Section: Comparing Scalar Quantities Of Div1d and 1d Mapped Solps-ite...mentioning

confidence: 99%

Benchmark of a self-consistent dynamic 1D divertor model DIV1D using the 2D SOLPS-ITER code

Derks

Frankemölle

Koenders

et al. 2022

Plasma Phys. Control. Fusion

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This paper presents DIV1D, a new 1D dynamic physics-based model of the divertor plasma under development to study and control the dynamics of detached plasmas. An innovative feature of DIV1D is that it mimics cross-field transport using an effective flux expansion and includes a neutral gas background outside the divertor leg. We outline a 1D mapping procedure for static 2D SOLPS-ITER simulations of divertor plasmas in the Tokamak à Configuration Variable (TCV) which can be used to benchmark 1D codes. For DIV1D good agreement is found for the most important divertor plasma quantities along the leg (e.g. densities, temperature, heat flux, and velocity) both in qualitative and quantitative sense. In addition, the comparison with SOLPS-ITER demonstrates that DIV1D self-consistently captures the evolution of divertor plasma quantities in the main heat flux channel as function of the upstream plasma density in a scan from 2 to 3 · 1019 m−3. The agreement is ascribed to the unique account of cross-field transport in DIV1D with an effective flux expansion and the interaction with an external neutral gas background

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Diagnosing the pedestal magnetic field and magnetohydrodynamics radial structure with pedestal–scrape of layer electron cyclotron emission radiation inversion in H-mode plasma (invited)

Zhu

Austin

et al. 2022

Review of Scientific Instruments

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Forward modeling is used to interpret inversion patterns of the pedestal–Scrape of Layer (SOL) Electron Cyclotron Emission (ECE) in DIII-D H-mode experiments. The modeling not only significantly improves the ECE data interpretation quality but also leads to the potential measurements of (1) the magnetic field strength |B| at the separatrix, (2) the pedestal |B| evolution during an inter-Edge Localized Mode (ELM) period, and (3) the pedestal Magnetohydrodynamics (MHD) radial structure. The ECE shine-through effect leads to three types of pedestal–SOL radiation inversions that are discussed in this paper. The first type of inversion is the non-monotonic T e, rad profile with respect to the major radius. Using the ECE frequency at the minimum T e, rad, the inversion can be applied to measure the magnetic field |B| at the separatrix and calibrate the mapping of the ECE channels with respect to the separatrix. The second type of inversion refers to the opposite phase between the radiation fluctuations δT e, rad at the pedestal and SOL. This δT e, rad phase inversion is sensitive to density and temperature fluctuations at the pedestal foot and, thus, can be used to qualitatively measure the MHD radial structure. The third type of inversion appears when the pedestal and SOL T e, rad evolve in an opposite trend, which can be used to infer the pedestal |B| field change during an inter-ELM period. The bandwidth effect on measuring δT e, rad due to pedestal MHD is also investigated in the radiation modeling.

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ECEI characterization of pedestal fluctuations in quiescent H-mode plasmas in DIII-D

Abstract: Electron cyclotron emission imaging (ECEI) is employed to characterize the magneto hydraulics dynamics (MHD) fluctuations at the quiescent H-mode pedestals in DIII-D. Pedestal MHD fluctuations cause ECE radiation temperature fluctuations δ T e … Show more

Cited by 9 publications

References 54 publications

A synthetic diagnostics platform for microwave imaging diagnostics in tokamaks

A synthetic diagnostics platform for microwave imaging diagnostics in tokamaks

Benchmark of a self-consistent dynamic 1D divertor model DIV1D using the 2D SOLPS-ITER code

Diagnosing the pedestal magnetic field and magnetohydrodynamics radial structure with pedestal–scrape of layer electron cyclotron emission radiation inversion in H-mode plasma (invited)

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