Progress of microwave diagnostics development on the HL-2A tokamak

Shi, Z.B.; Zhong, Weizhi; Jiang, M.

doi:10.1088/2058-6272/aad27b

Cited by 16 publications

(9 citation statements)

References 48 publications

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“…Key diagnostic tools employed include a multi-channel electron cyclotron emission (ECE) system, which shares a common sightline and horn antenna with the CECE system, and a Doppler backscattering (DBS) reflectometer located at a toroidal angle of 22.5 • relative to the ECE window. [38] The DBS instrument provides valuable information about plasma rotation, density fluctuations, and radial electric fields.…”

Section: Methodsmentioning

confidence: 99%

Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas

Shi 石,

Fang 方,

Li 李

et al. 2024

Chinese Phys. B

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The dynamics of long-wavelength ($k_\theta<1.4 \mathrm{\ cm^{-1}}$), broadband (20-200 kHz) electron temperature fluctuations ($\tilde T_e/T_e$) of plasmas in gas-puff experiments were observed for the first time in HL-2A tokamak. In a relative low density ($n_e(0) \simeq 0.91 \sim 1.20 \times10^{19}/m^3$) scenario, after gas-puffing the core temperature increases and the edge temperature drops. On the contrary, temperature fluctuation drops at the core and increases at the edge. Analyses show the non-local emergence is accompanied with a long radial coherent length of turbulent fluctuations. While in a higher density ($n_e(0) \simeq 1.83 \sim 2.02 \times10^{19}/m^3$) scenario, the phenomena were not observed. Furthermore, compelling evidence indicates that $\textbf{E} \times \textbf{B}$ shear serves as a substantial contributor to this extensive radial interaction. This finding offers a direct explanatory link to the intriguing core-heating phenomenon witnessed within the realm of non-local transport.

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Section: Methodsmentioning

confidence: 99%

Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas

Shi 石,

Fang 方,

Li 李

et al. 2024

Chinese Phys. B

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“…The beat frequency of the system is calibrated to a constant value at the plasma edge with a well-designed control waveform. These techniques can simplify the data analysis and improve the measurement without hardware modification [26]. Measurement of the density profiles during an ELM event illustrate the improvement of the system.…”

Section: Turbulence Diagnostic Developmentmentioning

confidence: 99%

“…Wenjin Chen developed seven channels of MSE on HL-2A in order to observe the safety factor profile directly. Jie Wen reported the data analysis method for Doppler Reflectometer [26], in which the dual Gaussian fitting was shown to improve the accuracy of the turbulence measurement. Lin Nie compared three kinds of probes to adopt them in plasmas with Maxwellian and bi-Maxwellian velocity distributions, in order to measure the radial electric field and its shear correctly [80].…”

Section: Ep Modeling and Diagnostic Developmentmentioning

confidence: 99%

Summary of the 8th Asia-Pacific Transport Working Group (APTWG) Meeting

Shi

Cheng

et al. 2019

Nucl. Fusion

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This conference report gives a summary on the contributed papers and discussions presented at the 8th Asia-Pacific Transport Working Group Meeting held at the Engineering & Technical College of Chengdu University of Technology, Leshan, China, from 12 to 15 June 2018. The objective of the meeting is to develop a predictive understanding of the physical mechanisms responsible for particle, energy and momentum transport in magnetically confined plasmas. In order to achieve this objective, five technical working groups were organized under the headings: (A) edge/SOL turbulence and L-H/H-L transition, (B) core-edge turbulence coupling, and transport in high beta plasmas, (C) transport and turbulence in 3D magnetic topology, (D) interaction between energetic particles, MHD instabilities and turbulence, and (E) model reduction and experiments for validation. A summary of the selected significant progresses from the presentations in the five technical working groups is given. The Young Researchers Forum which was held in this meeting is described.

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“…ECE radiometry is a powerful Te and Te perturbation (δTe) diagnostic with high spatial-temporal resolution and it has been established on many tokamaks [1][2][3][4]. The calibration of the ECE radiometry is the key step in obtaining the absolute or relative Te profile.…”

Section: Introductionmentioning

confidence: 99%

Upgrade of the relative calibration methods and Bayesian inference processing for electron cyclotron emission radiometry

Shi

Yang

et al. 2023

EPJ Web Conf.

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An upgraded local oscillator (LO) hopping calibration method based on a blackbody hot source and a perturbation analysis of the magnetic field difference method are introduced in this work. The blackbody hot source is used to evaluate the difference in the relative coefficients between the two LO hopping frequencies in the same channels. Then the coefficients are obtained by multiplying the LO hopping frequencies coefficients by LO hopping calibration coefficients. In this way, it is more flexible and stable than the in-situ calibration. The magnetic field difference method provides another calibration method to obtain the relative calibration coefficients of the electron cyclotron emission radiometers (ECE). In general, the magnetic field difference method needs two similar shots but with a difference of 2.1% (for HL-2M) in the magnetic field. Meanwhile, there are some errors because of the deviation of detection positions in the same channels between the two shots. For evaluating the calibration errors, the impact of the displacement, Te perturbation of the core region, and magnetic field difference has been discussed. The result shows that a larger magnetic field difference can improve the accuracy of the calibration. In the end, Bayesian inference has been utilized to evaluate the calibration coefficients and get the most probable calibration coefficients along with its the confidence interval.

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Progress of microwave diagnostics development on the HL-2A tokamak

Cited by 16 publications

References 48 publications

Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas

Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas

Summary of the 8th Asia-Pacific Transport Working Group (APTWG) Meeting

Upgrade of the relative calibration methods and Bayesian inference processing for electron cyclotron emission radiometry

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