Characteristic properties of the frame-antenna-produced RF discharge evolution in the Uragan-3M torsatron

Chechkin, V. V.; Григорьева, Л.И.; Pavlichenko, R. O.; Kulaga, A. Ye.; Zamanov, N. V.; Moiseenko, V. E.; Burchenko, P. Ya.; Lozin, A.V.; Tarasov, I. K.; Pankratov, I. M.; Grekov, D. L.; Beletskii, A. A.; Kasilov, A. A.; Voitsenya, V. S.; Pashnev, V. K.; Konovalov, V.G.; Shapoval, A. N.; Mironov, Yu.K.; Romanov, V. S.

doi:10.1134/s1063780x14080030

Cited by 8 publications

(4 citation statements)

References 13 publications

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“…As of March 2014, experimental data from the two tokamaks ASDEX Upgrade (AUG) 18 and MAST, 19 as well as the five stellarators HSX, 20 TJ-K, 21 Uragan-3M (U3M), 22 Wendelstein 7-AS (W7AS) 23 and WEGA 24 has been collected in the ETDB. There are two available datasets from W7AS and WEGA, taken at different magnetic field strengths.…”

Section: The Edge Turbulence Databasementioning

confidence: 99%

Scaling and transport analyses based on an international edge turbulence database

Simon

Ramisch

Beletskii

et al. 2014

Plasma Phys. Control. Fusion

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Microscopic turbulence properties in the edge of toroidally confined fusion plasmas are studied by comparative analysis of experimental data from seven devices, collected in an international edge turbulence database. The database contains Langmuir probe measurements of fluctuations in the floating potential and ion saturation current across the last closed flux surface. They are used to address statistical properties and particle transport. Universal features of plasma edge turbulence such as an increase in skewness across the scrape-off layer (SOL) as footprints of density blobs are recovered in all devices. Analysis of the correlation lengths and times reveals power law scaling relations with macroscopic drift-wave parameters, albeit weaker than would be expected for drift-wave turbulence. As a result, the turbulent diffusivity scales with the inverse of the magnetic field strength, which is closer to Bohm-like scaling than to gyro-Bohm scaling. Nearly identical scaling relations are determined in the confined plasma edge and the SOL, pointing to a strong connection between drift-wave turbulence in the edge and blobs in the SOL. The contributions of blobs and holes (negative density spikes) to the radial particle transport are analyzed qualitatively with a conditional averaging approach. Blobs are connected to outward transport in the SOL of all devices whereas holes exhibit no uniform propagation pattern.

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Section: The Edge Turbulence Databasementioning

confidence: 99%

Scaling and transport analyses based on an international edge turbulence database

Simon

Ramisch

Beletskii

et al. 2014

Plasma Phys. Control. Fusion

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“…Исследования проводились в торсатроне У-3М [9] при величине магнитного поля на геометрической оси плазменной конфигурации B 0 ≈ 0.72 T. Малый усредненный радиус плазмы a ≈ 0.1 m, а большой радиус тора R ≈ 1 m. Плазма создавалась и нагревалась в режиме ВЧ-нагрева [10] на частотах, близких к ионной циклотронной частоте ω ≈ 0.8ω ci , где ω ci -циклотронная частота ионов рабочего газа. В качестве рабочего газа использовался водород.…”

Section: экспериментальные условияunclassified

Структура Магнитных Флуктуаций Плазмы В Торсатроне Ураган-3м При Редких Частотах Соударений

Пашнев¹,

Сороковой²,

Петрушеня³

et al. 2019

Журнал Технической Физики

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Fluctuations of the poloidal component of the plasma magnetic field in the frequency range of 0.5–50 kHz are studied in the Uragan-3M (U-3M) torsatron. Hydrogen plasma is produced and heated by RF fields at frequencies close to that of the ion cyclotron. The studies are carried out using a set of 15 magnetic sensors installed in one of the torus cross sections. RF heating provided the plasma with rare collision frequencies and the presence of the bootstrap current. The study is carried out when the maximum amplitude of magnetic fluctuations is observed and their connection with the plasma energy content is noticeable. Two types of vibrations are observed. In the first type, the current structure rotates with a certain frequency mainly in the direction of the rotation of electrons in the magnetic field, and the amplitude varies slowly with time (the rotating structure). For the second type, the spatial structure does not rotate, but its amplitude changes with a certain frequency (the standing structure). The frequencies of fluctuations and rotations are close for structures with a given poloidal wave number. The standing vibration structures with different poloidal wave numbers in this frequency range are correlated. The maximum amplitude of the rotating structures is observed with m = 2, and for the standing structures with m = 3 and reaches the values of $$\tilde {B}$$ ≤ 0.3 G in the confinement region. The vibration frequency does not depend on poloidal wave number m for the studied cases; m = 0, 1, 2, 3.

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“…The THT antenna is 28 cm and 42 cm long in toroidal and poloidal directions, respectively. A more detailed description of the antennas is given in [8,9]. They generate waves with wide k || spectrum.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of regular discharges in Uragan-3M torsatron

Moiseenko¹,

Shapoval²,

Lozin³

et al. 2019

Plasma Phys. Control. Fusion

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The Uragan-3M device is equipped with two antennas which are fed by RF power with the frequency below ion cyclotron. The frame antenna was used for pre-ionization and the three-half turn antenna makes plasma heating. In this experimental series, the radial profiles of C III, O V and C V optical line intensity and the second cyclotron harmonic emission are measured using a pulse-by-pulse technique. The results of these measurements and Biot-Savart calculations of the Uragan-3M magnetic configuration could be explained by the existence of a small central area with relatively high electron temperature and good plasma confinement surrounded by a zone where the electron temperature and confinement are worse. The relatively low average electron temperature and high RF power needed to sustain plasma are the consequences.

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Characteristic properties of the frame-antenna-produced RF discharge evolution in the Uragan-3M torsatron

Cited by 8 publications

References 13 publications

Scaling and transport analyses based on an international edge turbulence database

Scaling and transport analyses based on an international edge turbulence database

Структура Магнитных Флуктуаций Плазмы В Торсатроне Ураган-3м При Редких Частотах Соударений

Characteristics of regular discharges in Uragan-3M torsatron

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