Design and implementation of an interferometer with high stability and wide dynamic range for steady-state plasmas

Zhong, Huanhuan; Ling, Bili; Wang, S.Z.; Wang, B.B.; Tan, Yidong; Gao, Zhe

doi:10.1016/j.fusengdes.2018.01.062

Cited by 4 publications

(1 citation statement)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SUNIST [26] is a small spherical tokamak with aspect ratio A = R 0 /r 0 ∼ 1.3 , major radius R 0 = 0.3 m, minor radius r 0 = 0.23 m, elongation κ = 1.6, plasma current I p ⩽ 100 kA, toroidal magnetic field B Φ ⩽ 0.3 T. The line averaged electron density is monitored by a 105.96 GHz heterodyne interferometer based on single sideband modulation, which features extremely low noise [27]. Three sets of magnetic probe (MP) arrays are placed in the vacuum vessel to systematically study the spatial structures of the TM activity.…”

Section: Device and Diagnosticsmentioning

confidence: 99%

Experimental study of the tearing mode instability during the current ramp up stage in Sino-United Spherical Tokamak

Zhong¹,

Tan²,

Gao³

2018

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

The fierce magnetohydrodynamic (MHD) activity observed during the current ramp up stage of a tokamak discharge, which significantly limits the performance of the plasma, has been experimentally studied in Sino-United Spherical Tokamak (SUNIST). The mode structure extracted by magnetic measurements appears to be typically decreasing from m/n = −6/−1 to m/n = −3/−1, where m and n are the poloidal and toroidal mode numbers. A phase reversal layer in the spatial distribution of the magnetic perturbation extracts the approximate position of the magnetic island chain, which gives insight on the evolution of the internal structure of the MHD activity. A matrix equation method that includes corrections for the shadowing effect of the probe array has been developed so as to derive a more accurate estimation of the current density profile. The resulting current profile evolution qualitatively explains the decrease in poloidal mode number and the spontaneous suppression of the MHD activity. Statistical results of the MHD response suggest that the deterioration of the plasma confinement is closely related to the phase inversion position of the poloidal magnetic perturbation.

show abstract

Section: Device and Diagnosticsmentioning

confidence: 99%

Experimental study of the tearing mode instability during the current ramp up stage in Sino-United Spherical Tokamak

Zhong¹,

Tan²,

Gao³

2018

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

show abstract

Design and characterization of a single-channel microwave interferometer for the Helicon Physics Prototype eXperiment

Liu

et al. 2021

Fusion Engineering and Design

View full text Add to dashboard Cite

Implementation and data processing of a five-channel microwave interferometer with high temporal resolution and low noise on Sino-UNIted Spherical Tokamak

Zhong

Tan

et al. 2021

Review of Scientific Instruments

View full text Add to dashboard Cite

A five-channel microwave interferometer with high temporal resolution and high phase resolution has been developed for measuring electron density profiles and fluctuations on the Sino-UNIted Spherical Tokamak. A correction algorithm, based on the low signal amplitude detection, is proposed to eliminate the fringe jump errors. The correction algorithm achieves an accuracy of 92%. The density profile is reconstructed through the Park-matrix method, with the geometry of magnetic surfaces calculated by the equilibrium fitting. The reconstructed density profiles for discharges with supersonic molecular beam injection are in good agreement with the results of another 94 GHz single-channel horizontal interferometer and the Langmuir probes. The temporal resolution of the system is 0.5 µs and the line-integrated electron density resolution is 1 × 1015 m−2, which benefits from the single sideband modulation technique. Therefore, the multichannel interferometer system is capable of studying the details of the high-frequency (up to 200 kHz) density fluctuation such as that in the minor disruption event.

show abstract

Design and implementation of an interferometer with high stability and wide dynamic range for steady-state plasmas

Cited by 4 publications

References 13 publications

Experimental study of the tearing mode instability during the current ramp up stage in Sino-United Spherical Tokamak

Experimental study of the tearing mode instability during the current ramp up stage in Sino-United Spherical Tokamak

Design and characterization of a single-channel microwave interferometer for the Helicon Physics Prototype eXperiment

Implementation and data processing of a five-channel microwave interferometer with high temporal resolution and low noise on Sino-UNIted Spherical Tokamak

Contact Info

Product

Resources

About