Electron Density Measurement by Raman Calibration of the HuanLiuqi-2A Thomson Scattering System

Liu, Chunhua; Yuan, Huan; Feng, Zhaochi; Yao, Ke; Nie, Lin; Shang, Jie; Liang, Yi; Shi, Z.B.; Yang, Qingwei; Duan, Xuru

doi:10.1585/pfr.9.1402042

Cited by 6 publications

(2 citation statements)

References 15 publications

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“…A fixed spatial point is considered as an example in this study. It is known that each spatial point corresponds to four spectral channels ( j=1-4), and the spectral intensity [17] obtained for channel j can be written as a function of the electron temperature T e and the electron density where c geo is called the geometrical factor and can be obtained with Raman calibration [18], P is the incident laser power, Δl is the length along the laser beam of the scattering volume, r e =e 2 /(4πε 0 m e c 2 )=2.81×10 −15 m is the electron classic radius, τ j is the spectral transmission coefficient, and S is the form factor. The Selden expression is applied for the form factor S:…”

Section: The Maximum Likelihood Methodsmentioning

confidence: 99%

Integrated data analysis on the electron temperature profile of HL-2A with the Bayesian probability inference method

Pan¹,

Wang²,

Wang³

et al. 2022

Plasma Sci. Technol.

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The data analysis on tokamak plasmas is mainly based on various diagnostic systems, which are usually modularized and independent of each other. This leads to a large amount of data not fully and effectively exploited, so that it is not conducive to reveal the deep physical mechanism. In this paper, Bayesian probability inference (BPI) with machine learning methods has been applied to the electron cyclotron emission (ECE) and Thomson scattering (TS) diagnostic systems on HL-2A/2M, and the effects of integrated data analysis (IDA) on the electron temperature of HL-2A with Bayesian probability inference are demonstrated. A program is developed to infer the whole electron temperature profile with a confidence interval, and the program can be applied in the online analysis. The IDA results show that the full profile of the electron temperature can be obtained and the diagnostic information is more comprehensive and abundant with IDA. The inference models for electron temperature analysis are established and the developed programs will serve as an experimental data analysis tool of HL-2A/2M in the near future.

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Section: The Maximum Likelihood Methodsmentioning

confidence: 99%

Integrated data analysis on the electron temperature profile of HL-2A with the Bayesian probability inference method

Pan¹,

Wang²,

Wang³

et al. 2022

Plasma Sci. Technol.

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“…Only band pass filters could not eliminate the stray light, scattering light signals in some spectral channels are then contaminated seriously. In order to detect the scattering light in such strong stray laser light environment, a notch filter is tested and used in a HL-2A ordinary polychromator [7].…”

Section: Upgraded Core Thomson Scattering System On Hl-2amentioning

confidence: 99%

Improvement in data processing of Thomson scattering diagnostic on HL-2A tokamak

Liu¹,

Wang²,

Feng³

et al. 2015

J. Inst.

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There are two types of digitizers to acquire the values of Thomson scattering signals in HL-2A tokamak. One is charge-sensitive analogue-to-digital converters (Q-ADCs) which simply integrates the signal over a gate interval, and the other is transient recorders with 12 bits resolution and 1 GHz sampling rate at each channel. Because the Thomson scattering diagnostic is prone to electrical noisy environment, in which Q-switched Nd:YAG lasers and polychromators are located closely to the HL-2A device, the high speed transient digitizers are found helpful to reduce noise overlapped in Thomson scattering signals. After triggered by the front of TTL pulse generated by laser light, data acquisition is fulfilled from −250 ns to 250 ns, so that the temporal evolution of Thomson scattering signals is obtained. A Gaussian function is utilized to fit the pulse shape of the digitized scattering signal by nonlinear least square methods. By pulse fitting and data processing, the influence of background perturbations is substantially reduced. K: Data processing methods; Digital signal processing (DSP); Plasma diagnosticsinterferometry, spectroscopy and imaging 1Corresponding author.

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Impact of ambient temperature on the filter polychromators performance and accuracy of thomson scattering diagnostics

Zhang,

Gong,

Guo

et al. 2024

Nuclear Instruments and Methods in Physics Research Section A:

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Electron Density Measurement by Raman Calibration of the HuanLiuqi-2A Thomson Scattering System

Cited by 6 publications

References 15 publications

Integrated data analysis on the electron temperature profile of HL-2A with the Bayesian probability inference method

Integrated data analysis on the electron temperature profile of HL-2A with the Bayesian probability inference method

Improvement in data processing of Thomson scattering diagnostic on HL-2A tokamak

Impact of ambient temperature on the filter polychromators performance and accuracy of thomson scattering diagnostics

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