排序方式: 共有8条查询结果,搜索用时 15 毫秒
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Zuin M Cavazzana R Martines E Serianni G Antoni V Bagatin M Andrenucci M Paganucci F Rossetti P 《Physical review letters》2004,92(22):225003
Measurements of magnetic and electrostatic fluctuations in an applied field magneto-plasma-dynamic thruster have shown that a m/n=1/1 kink mode becomes unstable whenever the Kruskal-Shafranov limit is violated. A positive correlation is established between the kink and performance degradation at high current, which has until now prevented the use of this kind of thruster in space missions. 相似文献
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Vianello N Naulin V Schrittwieser R Müller HW Zuin M Ionita C Rasmussen JJ Mehlmann F Rohde V Cavazzana R Maraschek M;ASDEX Upgrade Team 《Physical review letters》2011,106(12):125002
Magnetically confined plasmas in the high confinement regime are regularly subjected to relaxation oscillations, termed edge localized modes (ELMs), leading to large transport events. Present ELM theories rely on a combined effect of edge current and the edge pressure gradients which result in intermediate mode number (n?10-15) structures (filaments) localized in the perpendicular plane and extended along the field lines. By detailed localized measurements of the magnetic field perturbation associated to type-I ELM filaments, it is shown that these filaments carry a substantial current. 相似文献
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Paccagnella R Ortolani S Zanca P Alfier A Bolzonella T Marrelli L Puiatti ME Serianni G Terranova D Valisa M Agostini M Apolloni L Auriemma F Bonomo F Canton A Carraro L Cavazzana R Cavinato M Franz P Gazza E Grando L Innocente P Lorenzini R Luchetta A Manduchi G Marchiori G Martini S Pasqualotto R Piovesan P Pomaro N Scarin P Spizzo G Spolaore M Taliercio C Vianello N Zaniol B Zanotto L Zuin M 《Physical review letters》2006,97(7):075001
Stable operation with control on magnetohydrodynamic modes has been obtained in the modified reversed field experiment employing a set of 192 feedback controlled saddle coils. Improvements of plasma temperature, confinement (twofold), and pulse length (threefold) and, as a consequence of the magnetic fluctuation reduction, strong mitigation of plasma-wall interaction and mode locking are reported. 相似文献
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Dalla Palma Mauro Cavazzana Roberto Erculiani Andrea Gambetta Giulio Peruzzo Simone 《Journal of Thermal Analysis and Calorimetry》2020,141(5):2061-2079
Journal of Thermal Analysis and Calorimetry - The laminar two-dimensional mixed convection in a trapezoidal enclosure with a rotating inner circular cylinder and a sinusoidal bottom wall is studied... 相似文献
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Spolaore M Antoni V Spada E Bergsåker H Cavazzana R Drake JR Martines E Regnoli G Serianni G Vianello N 《Physical review letters》2004,93(21):215003
Coherent structures identified in two reversed field pinch experiments are interpreted as a dynamic balance of dipolar and monopolar vortices growing and evolving under the effect of the ExB flow shear. For the first time their contribution to the anomalous transport has been estimated in fusion related plasmas, showing that they can account for up to 50% of the total plasma diffusivity. The experimental findings indicate that the diffusion coefficient associated with the coherent structures depends on the relative population of the two types of vortices and is minimum when the two populations are equal. An interpretative model is proposed to explain this feature. 相似文献
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E. Martines M. Spolaore V. Antoni G. Regnoli N. Vianello R. Cavazzana G. Serianni L. Tramontin 《Czechoslovak Journal of Physics》2001,51(10):983-993
Electrostatic turbulence in the edge region of the RFX device has been shown to be intermittent, i.e. not self-similar. In fact the probability distribution function of fluctuations at large scales is Gaussian in shape, whereas it displays strong tails for small scale fluctuations. The events responsible for these heavy tails are associated with turbulent structures with well defined density and floating potential spatial profiles, which have been characterised using arrays of probes. These structures tend to occur preferentially in correspondence to large scale magnetic relaxation events driven by core-resonant tearing modes. They also display an inclination related to the average velocity shear. 相似文献
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Vianello N Spada E Antoni V Spolaore M Serianni G Regnoli G Cavazzana R Bergsåker H Drake JR 《Physical review letters》2005,94(13):135001
The momentum balance has been applied to the ExB flow in the edge region of a reversed field pinch (RFP) configuration. All terms, including those involving fluctuations, have been measured in stationary condition in the edge region of the Extrap-T2R RFP experiment. It is found that the component of the Reynolds stress driven by electrostatic fluctuations is the term playing the major role in driving the shear of the ExB flow to a value marginal for turbulent suppression, so that the results are in favor of a turbulence self-regulating mechanism underlying the momentum balance at the edge. Balancing the sheared flow driving and damping terms, the plasma viscosity is found anomalous and consistent with the diffusivity due to electrostatic turbulence. 相似文献
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Spada E Carbone V Cavazzana R Fattorini L Regnoli G Vianello N Antoni V Martines E Serianni G Spolaore M Tramontin L 《Physical review letters》2001,86(14):3032-3035
In order to test the self-organized criticality (SOC) paradigm in transport processes, a novel technique has been applied for the first time to plasmas confined in reversed field pinch configuration. This technique consists of an analysis of the probability distribution function of the times between bursts in density fluctuations measured by microwave reflectometry and electrostatic probes. The same analysis has also been applied to intermittent events sorted out from the Gaussian background. In both cases, the experimental results disagree with the predictions for a SOC system. 相似文献
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