The design of a correlation electron cyclotron emission system on J-TEXT

Yang, Zhoujun; Xiao, Yao; D., X.; Pan, Xiaolong; Xiao, Jinshui

doi:10.1063/1.4917271

Cited by 12 publications

(4 citation statements)

References 12 publications

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“…The correlation electron cyclotron emission (CECE) diagnostic and microwave Doppler backscattering (DBS) diagnostic are also adopted in this work to get information about plasma turbulence. The electron temperature fluctuations at different locations can be provided by the CECE diagnostic [20,21]. It includes 14 channels, and shares a set of radio frequency sources with the ECE system.…”

Section: Experimental Setup and Related Diagnosticsmentioning

confidence: 99%

Observation of the electron thermal transport and temperature fluctuations for electron cyclotron resonance heated plasmas on J-TEXT

Yang¹,

Zhang²,

Ren³

et al. 2021

Nucl. Fusion

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First dedicated experiments have been carried out on the J-TEXT tokamak for investigating the electron thermal transport and plasma fluctuations before and during electron cyclotron resonance heating (ECRH). The electron thermal diffusivities are calculated using the diffusive space-time evolution characteristic of the electron temperature perturbations produced by internal sawtooth collapse. It is found that the electron thermal diffusivity significantly increases as ECRH is turned on. The temperature fluctuations in the ECRH-assisted ohmic plasmas measured by the correlation electron cyclotron emission (CECE) diagnostic have a larger amplitude and broader bandwidth than that of pure ohmic plasmas. However, there is a slight change in the density fluctuations. The electron thermal diffusivities and the bandwidth of the electron temperature fluctuations decrease simultaneously as density increases in ohmic plasmas. However, the same trend is not found for ECRH-assisted ohmic plasmas with fixed ECRH power. The electron thermal diffusivities increase almost linearly with the ECRH power for the same discharge parameters, while the temperature fluctuations become broader at the same time. Linear stability analysis using the gyrokinetic electromagnetic numerical experiment code indicates that there is a turbulence transition from the mixed mode of ion temperature gradient mode and trapped electron mode (TEM) to the pure (broader) TEM when changing from pure ohmic to ECRH-assisted ohmic plasmas. It is consistent with the temperature fluctuations measured by CECE, which is sensitive to the long-wavelength modes. All these results suggest that the long-wavelength temperature fluctuations play an important role in electron thermal transport. In ECRH-assisted ohmic plasmas, electron thermal transport may become dominated by ETGs when TEMs are suppressed at high density.

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Section: Experimental Setup and Related Diagnosticsmentioning

confidence: 99%

Observation of the electron thermal transport and temperature fluctuations for electron cyclotron resonance heated plasmas on J-TEXT

Yang¹,

Zhang²,

Ren³

et al. 2021

Nucl. Fusion

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“…In JTEXT, the electron temperature (T e ) is measured with an electron cyclotron emission radiometer (ECE) [19]. At the same time, the fluctuation in T e for core plasma is measured using a correlation ECE radiometer (CECE) [20]. A 17channel polarizerinterferometry system (POLARIS) [21], which cov ers the whole region of JTEXT plasma from the high field side to the low field side, measures the electron density (n e ).…”

Section: Observation Of Multi-channel Non-local Transport In J-text P...mentioning

confidence: 99%

Observation of multi-channel non-local transport in J-TEXT plasmas

et al. 2018

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In cold pulse experiments in J-TEXT, not only are rapid electron temperature increases in core observed, but also steep rises of inner density are found. Moreover, some evidence of acceleration of the core toroidal rotation is also observed during the non-local transport process of electron temperature. These new findings of cold pulse experiments in J-TEXT suggest that turbulence spreading is possible mechanism for the non-local transport dynamics.

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“…However, there is an inherent limitation for a typical ECE signal on detecting the lowest level of electron temperature perturbations, especially the high frequency fluctuations (20-500 kHz) which may be related to turbulence. A technique, known as correlation electron cyclotron emission (CECE) will eliminate the thermal noise and increase the sensitivity for measurement, and has been successfully used on some fusion devices [48][49][50]. The typical method used in the CECE relies on the spectral decorrelation properties of the thermal electron cyclotron emission.…”

Section: New Developing Diagnosticsmentioning

confidence: 99%

“…In a multichannel CECE, the IF signal will be divided by a power divider, and then be processed by an amplifier, band pass filter and detector. To satisfy the spectral decorrelation, the bandwidth of IF and video frequency should be carefully selected [49,50].…”

Section: Ghz Sampling Digital Correlation Electron Cyclotron Emissionmentioning

confidence: 99%

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

Shi

Zhong

Jiang

2018

Plasma Sci. Technol.

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Sets of powerful microwave diagnostic systems have been developed on the HL-2A tokamak, including 18 subsystems with high spatial and temporal resolutions. These systems have been applied in the HL-2A tokamak experiments to investigate the core plasma transport, turbulence, MHD, energetic particle physics and so on. In this paper, the microwave diagnostics and their applications are reviewed. Some new technologies, including GHz sampling digital correlation electron cyclotron emission (DCECE), multi-channel correlation reflectometers, and solid state terahertz interferometers, are also presented in the paper.

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The design of a correlation electron cyclotron emission system on J-TEXT

Cited by 12 publications

References 12 publications

Observation of the electron thermal transport and temperature fluctuations for electron cyclotron resonance heated plasmas on J-TEXT

Observation of the electron thermal transport and temperature fluctuations for electron cyclotron resonance heated plasmas on J-TEXT

Observation of multi-channel non-local transport in J-TEXT plasmas

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

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