Observation of short time-scale spectral emissions at millimeter wavelengths with the new CTS diagnostic on the FTU tokamak
| Autor: | V. Mellera, Cristian Galperti, M. Lontano, D. Ricci, F.P. Orsitto, Søren Bang Korsholm, E. Alessi, Ftu Team, G. Ramogida, J. Juul Rasmussen, Stefan Kragh Nielsen, G. Calabrò, Alessandro Bruschi, L. V. Lubyako, C. Mazzotta, Lorenzo Figini, S. Garavaglia, Gustavo Granucci, U. Tartari, A. Moro, V. Cocilovo, B. Baiocchi, Ocleto D'Arcangelo, William Bin, I. Casiraghi, Giovanni Grosso, M. Stejner, F. Belli |
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| Přispěvatelé: | Bruschi, A, Alessi, E, Bin, W, D'Arcangelo, O, Baiocchi, B, Belli, F, Calabro, G, Casiraghi, I, Cocilovo, V, Figini, L, Galperti, C, Garavaglia, S, Granucci, G, Grosso, G, Korsholm, S, Lontano, M, Lubyako, L, Mazzotta, C, Mellera, V, Moro, A, Nielsen, S, Orsitto, F, Ramogida, G, Rasmussen, J, Ricci, D, Stejner, M, Tartari, U, Ramogida, G., Mazzotta, C., Cocilovo, V., Calabrò, G., Belli, F., D'Arcangelo, O. |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Magnetic island
Nuclear and High Energy Physics Tokamak Parametric decay instabilities Parametric decay instabilitie Thomson scattering Plasma parameters Cyclotron Cyclotron resonance 01 natural sciences Electron cyclotron resonance 010305 fluids & plasmas law.invention law Physics::Plasma Physics Electron cyclotron heating 0103 physical sciences 010306 general physics Physics Collective Thomson scattering Resonance Plasma Magnetic islands Condensed Matter Physics __ Computational physics magnetic islands Atomic physics |
| Zdroj: | Bruschi, A, Alessi, E, Bin, W, D'Arcangelo, O, Baiocchi, B, Belli, F, Calabro, G, Casiraghi, I, Cocilovo, V, Figini, L, Galperti, C, Garavaglia, S, Granucci, G, Grosso, G, Korsholm, S B, Lontano, M, Lubyako, L, Mazzotta, C, Mellera, V, Del Moro, A, Nielsen, S K, Orsitto, F, Ramogida, G, Rasmussen, J, Ricci, D, Pedersen, M S & Tartari, U 2017, ' Observation of short time-scale spectral emissions at millimeter wavelengths with the new CTS diagnostic on the FTU tokamak : Paper ', Nuclear Fusion, vol. 57, no. 7, 076004 . https://doi.org/10.1088/1741-4326/aa6ce1 26th Fusion Energy Conference, Kyoto, Japan, 17-22 October 2016 info:cnr-pdr/source/autori:A. Bruschi (1; E. Alessi (1; W. Bin( 1; O. D'Arcangelo (2; B. Baiocchi (1; F. Belli (2; G. Calabrò (2; I. Casiraghi (3; V. Cocilovo (2; L. Figini (1; C. Galperti ( 4; S. Garavaglia (1; G. Granucci (1; G. Grosso (1; S.B. Korsholm (5; M. Lontano (1; L. Lubyako (6; V. Mellera (1; A. Moro (1; S.K. Nielsen (5; F. Orsitto (7; M.S. Pedersen (5; G. Ramogida (2; J. Rasmussen (5; D. Ricci (1; U. Tartari (1 and FTU Team*/congresso_nome:26th Fusion Energy Conference/congresso_luogo:Kyoto, Japan/congresso_data:17-22 October 2016/anno:2016/pagina_da:/pagina_a:/intervallo_pagine Nuclear fusion 57 (2017). doi:10.1088/1741-4326/aa6ce1 info:cnr-pdr/source/autori:Bruschi, A.; Alessi, E.; Bin, W.; D'Arcangelo, O.; Baiocchi, B.; Belli, F.; Calabro, G.; Casiraghi, I.; Cocilovo, V.; Figini, L.; Galperti, C.; Garavaglia, S.; Granucci, G.; Grosso, G.; Korsholm, S. B.; Lontano, M.; Lubyako, L.; Mazzotta, C.; Mellera, V.; Moro, A.; Nielsen, S. K.; Orsitto, F.; Ramogida, G.; Rasmussen, J.; Ricci, D.; Stejner, M.; Tartari, U./titolo:Observation of short time-scale spectral emissions at millimeter wavelengths with the new CTS diagnostic on the FTU tokamak/doi:10.1088%2F1741-4326%2Faa6ce1/rivista:Nuclear fusion/anno:2017/pagina_da:/pagina_a:/intervallo_pagine:/volume:57 Nuclear Fusion |
| ISSN: | 1748-0221 0029-5515 0741-3335 1536-1055 |
| DOI: | 10.1088/1741-4326/aa6ce1 |
| Popis: | The Collective Thomson Scattering (CTS) diagnostic on FTU tokamak was renewed for investigations on the excitation of Parametric Decay Instabilities (PDI) by Electron Cyclotron (EC) beams in presence of magnetic islands and their effects on the EC absorption. Experiments were performed launching a gyroton probe beam (140 GHz, 400 kW) and receiving the CTS beam in symmetric and asymmetric configurations with respect to the equatorial plane, in different conditions of plasma density and magnetic field (with or without the EC resonance in the plasma), and with magnetic islands generated by Neon injection. The acquisition with a fast digitizer allowed observing spectral features with very high time and frequency resolution. In the shots performed at 7.2 T, with the fundamental EC resonance out of the plasma region, a sequence of faint lines emitted with a fast temporal evolution have been observed in a range 0.5-1.1 GHz from the gyrotron frequency while at 4.7 T, with the resonance on the high field side of the plasma column, asynchronous "bursts" of continuous emissions were observed at a microsecond time scale. In 2015 and 2016 experiments were performed at 4.7 T and 3.6 T, in this last case with the plasma between the first and the second EC harmonics both lying outside the plasma volume. Different types of spectral features with a fast evolution were observed. Their correlation with magnetic probes and other fast signals from the plasma has been investigated, to characterize the observations and exclude parasitic effects, as well as breakdown phenomena in front of the antennas. The variation in the stray radiation distribution in the vessel has been studied with the aid of a diffusive model, to characterize variations on the probe beam absorption associated to the observed phenomena. The latest experiments, with a diagnostic improved both in frequency band (up to ±4.2 GHz from the probe) and with the addition of a second radiometer, are allowing a clearer interpretation of the emissions. |
| Databáze: | OpenAIRE |
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