Large vortex-density fluctuations induced by current in the Corbino-disk

2005 ◽  
Vol 426-431 ◽  
pp. 158-162 ◽  
Author(s):  
S. Okuma ◽  
S. Morishima ◽  
M. Kamada
Keyword(s):  
Density Fluctuations ◽  
Large Vortex ◽  
Vortex Density ◽  
Corbino Disk

scholarly journals Probing Vortex Density Fluctuations in Superfluid Turbulence

2008 ◽  
pp. 532-534
Author(s):  
P.-E. Roche ◽  
B. Chabaud ◽  
O. Français ◽  
L. Rousseau ◽  
H. Willaime
Keyword(s):  
Density Fluctuations ◽  
Superfluid Turbulence ◽  
Vortex Density

FLUX-FLOW NOISE IN THE VICINITY OF THE PEAK EFFECT

2002 ◽  
Vol 02 (01) ◽  
pp. L31-L36 ◽  
Author(s):  
Y. PALTIEL ◽  
G. JUNG ◽  
Y. MYASOEDOV ◽  
M. L. RAPPAPORT ◽  
E. ZELDOV ◽  
...  
Keyword(s):  
Metastable Phase ◽  
Peak Effect ◽  
Excess Noise ◽  
Current Fluctuations ◽  
Voltage Noise ◽  
Flux Flow ◽  
Velocity Fluctuations ◽  
Flow Noise ◽  
Large Vortex ◽  
Corbino Disk

Strong flux-flow voltage noise, commonly observed in the vicinity of the peak effect in superconductors, is ascribed to a novel noise mechanism. Random injection of the strongly pinned metastable disordered vortex phase through the sample edges and its subsequent random annealing into the weakly pinned ordered phase in the bulk result in large critical current fluctuations causing large vortex velocity fluctuations. In the Corbino disk configuration vortices do not cross sample edges, the injection of the metastable phase is prevented, and accordingly the excess noise is absent.

Ballooning structure in density fluctuations observed with the 2 MeV heavy ion beam probe on the TEXT-U tokamak

1995 ◽  
Author(s):  
A. Fujisawa ◽  
A. Ouroua ◽  
J.W. Heard ◽  
T.P. Crowley ◽  
P.M. Schoch ◽  
...  
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Density Fluctuations ◽  
Heavy Ion Beam ◽  
Heavy Ion Beam Probe

scholarly journals Looking for a proxy of the ionospheric turbulence with Swarm data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paola De Michelis ◽  
Giuseppe Consolini ◽  
Alessio Pignalberi ◽  
Roberta Tozzi ◽  
Igino Coco ◽  
...  
Keyword(s):  
Electron Density ◽  
Geomagnetic Activity ◽  
Density Fluctuations ◽  
Rate Of Change ◽  
Topside Ionosphere ◽  
Joint Probability Distribution ◽  
Activity Levels ◽  
Scaling Exponents ◽  
Electron Density Fluctuations ◽  
Scaling Features

AbstractThe present work focuses on the analysis of the scaling features of electron density fluctuations in the mid- and high-latitude topside ionosphere under different conditions of geomagnetic activity. The aim is to understand whether it is possible to identify a proxy that may provide information on the properties of electron density fluctuations and on the possible physical mechanisms at their origin, as for instance, turbulence phenomena. So, we selected about 4 years (April 2014–February 2018) of 1 Hz electron density measurements recorded on-board ESA Swarm A satellite. Using the Auroral Electrojet (AE) index, we identified two different geomagnetic conditions: quiet (AE < 50 nT) and active (AE > 300 nT). For both datasets, we evaluated the first- and second-order scaling exponents and an intermittency coefficient associated with the electron density fluctuations. Then, the joint probability distribution between each of these quantities and the rate of change of electron density index was also evaluated. We identified two families of plasma density fluctuations characterized by different mean values of both the scaling exponents and the considered ionospheric index, suggesting that different mechanisms (instabilities/turbulent processes) can be responsible for the observed scaling features. Furthermore, a clear different localization of the two families in the magnetic latitude—magnetic local time plane is found and its dependence on geomagnetic activity levels is analyzed. These results may well have a bearing about the capability of recognizing the turbulent character of irregularities using a typical ionospheric plasma irregularity index as a proxy.

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