Recent results of the T-10 tokamak

Vershkov, V.A.; Андреев, В. В.; Borschegovskiy, A. A.; Chistyakov, V. V.; Dremin, M. M.; Eliseev, L.G.; Gorbunov, E.P.; Grashin, S.A.; Khmara, A.V.; Kislov, A. Ya.; Kislov, D. A.; Komarov, A. D.; Kozachek, A.S.; Krupin, V.A.; Krupnik, L. I.; Krylov, S.V.; Лысенко, С. Е.; Maltsev, S.G.; Mavrin, V.A.; Melnikov, A. V.; Notkin, G.E.; Novikov, Alexander; Pavlov, Yu.D.; Perfilov, S.V.; Piterskij, V.V.; Ploskirev, G.N.; Poznyak, V. I.; Razumova, K.A.; Roy, I. N.; Ryzhakov, D.V.; Savrukhin, P. V.; Шестаков, Е. А.; Shelukhin, D. A.; Skosyrev, Y.; Shurygin, R. V.; Tilinin, G. N.; Trukhina, E.V.; Trukhin, V. M.

doi:10.1088/0029-5515/51/9/094019

Cited by 28 publications

(31 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The paper continues the series of previous publication devoted to the investigations of small-scale density fluctuation characteristics [1][2][3][4] and expands previous results with the new experimental material. The main goals of the paper were the confirmation of the different turbulence types and complete characterization of their properties.…”

Section: Introductionsupporting

confidence: 56%

3D structure of density fluctuations in the T-10 tokamak and new approach for current profile estimation

et al. 2019

Self Cite

View full text Add to dashboard Cite

Previous investigations of small-scale density fluctuation by means of correlation reflectometry in T-10 tokamak revealed the existence of several density fluctuation types and strong radial and poloidal variation of their amplitudes and correlation properties. This paper is focused on the new measurements of the 3D spatial distributions of the amplitudes, the radial correlation lengths and the long range correlations along the field lines for the different turbulence types. The properties of the density fluctuations were systematically studied with the improved reflectometers, data analyzing and acquisition hardware. The density fluctuations were measured by heterodyne correlation reflectometry using ordinary mode. New T-10 antenna set have horn antennae arrays at four places distributed toroidally and poloidally over tokamak torus. The experiments confirmed previously found strong poloidal amplitude asymmetry of the broad band and the quasi-coherent oscillations and the uniform poloidal distribution of stochastic low frequency fluctuations. The presence of those turbulence types was also proved by the measurements of perturbation properties using heavy ion beam probe diagnostic. The radial correlation measurements were performed at four poloidal angles to understand the poloidal dependence of the radial correlation length for the different fluctuation types. The significant decrease of the radial correlation lengths towards the high magnetic field side was observed for quasi-coherent and stochastic low frequency turbulence types. The long range correlations along the field lines were measured by the reflectometers in two cross-section separated by 1/4 of the torus. The reflectometers have the same frequency thus provide reflection from the same magnetic surface. Reflection radii are chosen by the frequency variation of the launched wave from shot to shot in a series of reproducible discharges. The measurements were carried out at the low and the high magnetic field side with two currents and simultaneous reverse of the direction of the toroidal magnetic field and the plasma current. Resonance radii were also calculated using 3D tracing of the magnetic field line and demonstrate good agreement with experiments. These results allow to propose the new approach for the current profile measurements in tokamaks.

show abstract

Section: Introductionsupporting

confidence: 56%

3D structure of density fluctuations in the T-10 tokamak and new approach for current profile estimation

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Following the discussion in [13] the complex amplitude spectrum is a super position of different components which can be described by Gaussian or Lorentzian shape. For the Γ-spectrum this decomposition can be done as well without the contribution of uncorrelated broad-band turbulence.…”

Section: General Observations From Short-range Correlationsmentioning

confidence: 99%

Long-range correlation properties of quasi-coherent modes at TEXTOR

Krämer‐Flecken

Soldatov

et al. 2015

New J. Phys.

View full text Add to dashboard Cite

The paper reports on the first measurements of long-range correlations along field lines in the center of ohmic plasmas at TEXTOR. The measurements are performed with correlation reflectometry. For the first time the poloidal, toroidal and radial extension of quasi-coherent modes are simultaneously investigated using correlation reflectometry at two poloidally and toroidally separated positions. The experiments also allow the local determination of the toroidal velocity from a combination of delay time estimation and safety factor measurements from the same instrument. The paper investigates whether turbulence and which kind of turbulence, with respect to the frequency range, is aligned along field lines and embedded on iso-density surfaces in ohmic plasmas. It especially addresses the question of the properties of coherent structures in the vicinity of the q = 1 surface by analyzing propagation times and coherence levels from short-and long-range correlations. The results are discussed within the context of quasi-coherent modes as observed at T-10, TEXTOR, Tore Supra and recently JET and which are linked to trapped electron modes. Furthermore, the experiment tries to investigate whether a treatment of turbulence in two dimensions is sufficient or if 3D geometry has to be used for the description of turbulence stimulated transport. This is of importance for the development of turbulence codes and simulations.

show abstract

“…For the study of ITG/ TEM, measuring quasi-coherent (QC) modes can be helpful because it is known that they appear in TEM dominant and low normalized collisionality regimes but suppressed in ITG dominant and high collisionality regimes. [15][16][17][18][19] QC modes have been observed in several tokamak machines such as T-10, 15 JET, 17 TEXTOR, 17 Tore Supra, [16][17][18] HL-2 A, and J-TEXT 19 and have revealed characteristics of both coherent modes and broadband fluctuations. In power spectra of electron density fluctuations, the mode shows a wide bandwidth (tens of kHz) around a peak frequency ranging from 30 kHz to 150 kHz.…”

Section: Introductionmentioning

confidence: 99%

Observation of electron driven quasi-coherent modes and their connection with core intrinsic rotation in KSTAR ECH and ohmic L-mode plasmas

Lee

Kwon

et al. 2018

Physics of Plasmas

View full text Add to dashboard Cite

Quasi-coherent (QC) modes, known as a type of the trapped electron mode (TEM) turbulence, have been measured in the outboard core region of low-density electron cyclotron resonant heating (ECH) injected and ohmically heated L-mode plasmas on the Korea Superconducting Tokamak Advanced Research (KSTAR) device. It appears that QC modes of 20-60 kHz occur or strengthen with an increase of the electron temperature to ion temperature ratio, but weaken or are fully suppressed by increased density/collisionality. Toroidal rotation shear, which is strongly related to the density/collisionality, also seems to stabilize the QC modes. Linear gyrokinetic simulations indicate that TEM is the most unstable mode at low densities where the QC modes are observed for both the ECH and ohmic plasmas. At high densities where the QC modes are suppressed, the most unstable mode is the ion temperature gradient (ITG) mode for the ECH plasmas but still TEM for the ohmic plasmas. In the ECH plasmas, it is found that the direction of the core toroidal intrinsic rotation is gradually reversed from the co-current to counter-current direction and the QC mode is suppressed as the line-averaged density increases, which can be explained by the transition of dominant micro-turbulence (TEM to ITG). However, in the ohmically heated plasmas, the acceleration of the core toroidal rotation is not fully explained by the TEM-ITG transition since the direction of the core toroidal rotation is counter-current direction when the QC mode is observed. Furthermore, the core toroidal rotation is accelerated to the counter-current direction even the line-averaged density decreases. Published by AIP Publishing. https://doi.

show abstract

Recent results of the T-10 tokamak

Abstract: This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 Nucl. Fusion 51 094019

Cited by 28 publications

References 13 publications

3D structure of density fluctuations in the T-10 tokamak and new approach for current profile estimation

3D structure of density fluctuations in the T-10 tokamak and new approach for current profile estimation

Long-range correlation properties of quasi-coherent modes at TEXTOR

Observation of electron driven quasi-coherent modes and their connection with core intrinsic rotation in KSTAR ECH and ohmic L-mode plasmas

Contact Info

Product

Resources

About