Design and initial operation of multichord soft x-ray detection arrays on the STOR-M tokamak

Xiao, C.; Niu, Ting Ting; Morelli, Jordan; Paz-Soldan, C.; Dreval, M.; Elgriw, S.; Pant, A.; Rohraff, D.; Trembach, D.; Hirose, Akira

doi:10.1063/1.2953493

Cited by 11 publications

(6 citation statements)

References 4 publications

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“…The outboard toroidal array is often used to determine the toroidal mode numbers up to n = 2. An SXR system consisting of two miniature pin-hole cameras is installed on STOR-M [31]. Each camera consists of a 20-channel photodiode linear array (IRD AXUV-20EL) of which only 12 are actually used.…”

Section: Methodsmentioning

confidence: 99%

Control of magnetic islands in the STOR-M tokamak using resonant helical fields

et al. 2011

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The resonant interaction between magnetohydrodynamic (MHD) instability modes and the externally applied helical magnetic field is demonstrated in the Saskatchewan Torus-Modified (STOR-M) tokamak. The study is conducted both numerically and experimentally using a 2D MHD equilibrium code in the former and an (l = 2, n = 1) helical coil carrying a short current pulse in the latter. It is shown numerically that the resonant helical current can efficiently suppress the magnetic islands resonating on the (m = 2, n = 1) magnetic surface when the value of the safety factor at the plasma edge is relatively low (⩽4). It is also found numerically that (2, 1) islands are induced when the applied helical current exceeds a threshold. The experimental study is performed in STOR-M during low-q ohmic discharges with high MHD activities. The amplitude and frequency of (2, 1) Mirnov fluctuations are significantly reduced after the activation of the resonant field. Lesser suppression in sideband islands is also observed. Moreover, a phase of improved plasma confinement, characterized by a reduction in Hα emission level, a reduction in loop voltage and an increase in the soft x-ray emission, is induced after application of the resonant field.

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Section: Methodsmentioning

confidence: 99%

Control of magnetic islands in the STOR-M tokamak using resonant helical fields

et al. 2011

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“…The soft x-ray (SXR) diagnostic system has been widely used in magnetic confinement fusion devices to reconstruct the two-dimensional (2D) SXR emission distribution for the investigation of plasma shape [1], magnetohydrodynamic (MHD) activities [2][3][4][5], impurity transport [6,7] and so on. For a toroidally symmetric tokamak plasma, several poloidal SXR arrays at certain toroidal locations are sufficient for tomography [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Development of a toroidal soft x-ray imaging system and application for investigating three-dimensional plasma on J-TEXT

ZHAO 赵,

LI 李,

ZHANG 张

et al. 2024

Plasma Sci. Technol.

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A toroidal soft X-ray imaging (T-SXRI) system has been developed to investigate the three-dimensional (3D) plasma physics on J-TEXT. This T-SXRI system consists of three sets of SXR arrays. Two sets are newly developed and located on the vacuum chamber wall at toroidal position ϕ of 126.4° and 272.6°, respectively, while one set is established previously at ϕ = 65.5°. Each set of SXR arrays consists of 3 arrays viewing the plasma poloidally, and hence can be used separately to obtain the SXR imaging via the tomographic method. The sawtooth precursor oscillations are measured by T-SXRI. The corresponding images of SXR perturbations are successfully reconstructed at three toroidal positions, hence forms a 3D measurement of the sawtooth precursor. The observed 3D structure is consistent with the helical structure of the m/n = 1/1 mode. The experimental observation confirms that the T-SXRI system is capable of observing the 3D structure of the plasma.

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“…Given measurements of multiple chords, the spatial profile of the electron temperature can be found with the use of tomographic inversion techniques. 7 The two-foil technique has been used on a number of current-carrying axisymmetric plasmas including reversed field pinch, [8][9][10] tokamak, 11,12 and stellarator plasmas. 13 Similar systems using multiple (more than two) foils have also been developed recently.…”

Section: Introductionmentioning

confidence: 99%

Design and initial operation of a two-color soft x-ray camera system on the Compact Toroidal Hybrid experiment

Herfindal

Dawson

Ennis

et al. 2014

Review of Scientific Instruments

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A multi-camera soft x-ray diagnostic has been developed to measure the equilibrium electron temperature profile and temperature fluctuations due to magnetohydrodynamic activity on the Compact Toroidal Hybrid experiment. The diagnostic consists of three separate cameras each employing two 20-channel diode arrays that view the same plasma region through different beryllium filter thicknesses of 1.8 μm and 3.0 μm allowing electron temperature measurements between 50 eV and 200 eV. The Compact Toroidal Hybrid is a five-field period current-carrying stellarator, in which the presence of plasma current strongly modifies the rotational transform and degree of asymmetry of the equilibrium. Details of the soft x-ray emission, effects of plasma asymmetry, and impurity line radiation on the design and measurement of the two-color diagnostic are discussed. Preliminary estimates of the temperature perturbation due to sawtooth oscillations observed in these hybrid discharges are given.

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Design and initial operation of multichord soft x-ray detection arrays on the STOR-M tokamak

Cited by 11 publications

References 4 publications

Control of magnetic islands in the STOR-M tokamak using resonant helical fields

Control of magnetic islands in the STOR-M tokamak using resonant helical fields

Development of a toroidal soft x-ray imaging system and application for investigating three-dimensional plasma on J-TEXT

Design and initial operation of a two-color soft x-ray camera system on the Compact Toroidal Hybrid experiment

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