Features of self-organized plasma physics in tokamaks

Razumova, K. A.

doi:10.1088/1361-6587/aa9099

Cited by 2 publications

(2 citation statements)

References 26 publications

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“…The first non-disruptive tokamak pulse, also known as a magnetohydrodynamical (MHD) stable plasma, was obtained on the TM-2 tokamak in 1962 [1][2][3][4][5]. The TM-2 experiments manifested Shafranov's predictions for MHD stable plasmas [6].…”

Section: Introductionmentioning

confidence: 95%

Overview of disruptions with JET-ILW

Gerasimov¹,

Abreu²,

Artaserse³

et al. 2020

Nucl. Fusion

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The paper presents an analysis of disruptions occurring during JET-ILW plasma operations covering the period from the start of ILW (ITER-like wall) operation up to completion of JET operation in 2016. The total number of disruptions was 1951 including 466 with deliberately induced disruptions. The average rate of unintended disruptions was 16.1 %, which is significantly above the ITER target at 15 MA. The pre-disruptive plasma parameters are: plasma current I p = (0.82-3.38) MA, toroidal field B T = (0.98-3.4) T, safety factor q 95 = (1.52-9.05), plasma internal inductance l i = (0.58-1.86), Greenwald density limit fraction FGWL = (0.04-1.61), with 720 X-point plasma pulses from a subset of 1420 unintended disruption shots. Massive gas injection (MGI) has been routinely used in protection mode both to terminate pulses when the plasma is at risk of disruption and to mitigate against disruption effects. The MGI was mainly triggered by the n = 1 locked mode (LM) amplitude exceeding a threshold or by the disruption itself, namely, either dI p /dt (specifically, a fast drop in I p ) or the toroidal loop voltage exceeding threshold values. For mitigation purposes, only the LM was used as a physics precursor and threshold on the LM signal was used to trigger a See Joffrin et al 2019 (

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Section: Introductionmentioning

confidence: 95%

Overview of disruptions with JET-ILW

Gerasimov¹,

Abreu²,

Artaserse³

et al. 2020

Nucl. Fusion

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“…The various SXR data modeling can decode some properties of MHD modes from complex SXR signals. A spectral analysis of raw SXR signals can be used to determine the radial locations of MHD modes without tomographic inversion [5][6][7][8][9]. The poloidal mode number and radial location can be determined using a singular value decomposition (SVD) technique [5,7].…”

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confidence: 99%

Determination of MHD mode structures using soft x-ray diagnostics in TCV

Dreval¹,

Sharapov²,

Vallar³

et al. 2023

Plasma Phys. Control. Fusion

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A forward modeling technique is developed for determining the characteristic features of observed MHD modes from the line-of-sight data of the soft X-ray (SXR) diagnostics with 64 vertical lines-of- sights in the TCV tokamak. This technique with the use of the diagnostics with excellent spatial resolution is shown to evaluate the poloidal mode numbers m, radial location and ballooning character of the MHD modes. At the first stage the poloidal mode structures have been modeled by the radially localized Gaussian-shaped emission regions rotating along the magnetic flux surfaces. At the second stage, the space structures of observed 95-100 kHz toroidal Alfvén eigenmodes (TAEs) are investigated numerically using HELENA, CSCAS and MISHKA codes. The calculated TAE eigenfunctions are used then in our forward modeling similarly to the approach of contrast imaging diagnostics [Edlund E M et al 2009 Phys. Rev. Lett. 102 165003] and SXR diagnostics [Piovesan P et al 2008 Nucl. Fusion 48 065001]. A ballooning structure of the observed n=1 TAE mode can be analyzed more easily due to the low poloidal mode number m in contrast to the high m modes analyzed by similar SXR technique in W7-X stellarator [M B Dreval et al 2021 Plasma Phys. Control. Fusion 63 065006].

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Features of self-organized plasma physics in tokamaks

Cited by 2 publications

References 26 publications

Overview of disruptions with JET-ILW

Overview of disruptions with JET-ILW

Determination of MHD mode structures using soft x-ray diagnostics in TCV

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