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Rached D.,Laboratoire Of Physique Des Plasmas | Madani Yssad H.,Laboratoire Lte Departement Of Genie Mecanique
Acta Physica Polonica A | Year: 2015

A solar cell (indium tin oxide (ITO)/p-doped amorphous silicon (p-a-Si:H)/intrinsic polymorphous silicon (i-pm-Si:H)/n-doped crystalline silicon (n-c-Si)) simulation, focused on p-layer doping density NA and surface band bending Esbb at the interface ITO/p-layer has been performed. Despite the deterioration of p-layer material quality with doping density, the reduced bulk recombination was found to compensate for the increased loss in the p-layer. An increase of p-layer doping density NA and contact barrier height φb0 (variation of the surface band bending Esbb) leads to an increase of the efficiency of heterojunction with intrinsic thin layer solar cells. © 2015, Polish Academy of Sciences. All rights reserved.

Liang J.,University of Calgary | Uritsky V.,University of Calgary | Donovan E.,University of Calgary | Ni B.,University of California at Los Angeles | And 6 more authors.
Journal of Geophysical Research: Space Physics | Year: 2010

We present multiprobe, multi-instrument observations of the electron cyclotron harmonic (ECH) emissions and ultralow-frequency (ULF) waves from Time History of Events and Macroscale Interactions during Substorms (THEMIS) and explore their potential linkage to the concurrent ground-observed pulsating auroras (PsA) on 4 January 2009. The ECH emissions were observed as discrete packets modulated by the ULF flapping motion of the neutral sheet around the probes. Combining different data sets of the ECH observations, we infer that the ECH emission intensities were strongly fluctuating and contained multi-time scale fine structures. The distribution of PsA patches featured longitudinal "wavelength" in concert with the in situ ULF wave characteristics inferred from a cross-phase analysis. The overall activeness of the PsA correlated with the in situ-measured energetic electron fluxes and ECH wave intensities. We suggest that ECH waves played the key role in the pitch angle diffusion of the plasma sheet electrons that led to the PsA, while the ULF waves structured the plasma sheet and imposed a macroscopic effect over the spatial distribution of the PsA. Copyright 2010 by the American Geophysical Union.

Huang S.Y.,Wuhan University | Huang S.Y.,Chinese Academy of Sciences | Zhou M.,Chinese Academy of Sciences | Zhou M.,Nanchang University | And 10 more authors.
Geophysical Research Letters | Year: 2012

We present the first comprehensive observations of turbulence properties within high speed reconnection jet in the plasma sheet with moderate guide field. The power spectral density index is about-1.73 in the inertial range, and follows the value of-2.86 in the ion dissipation range. The turbulence is strongly anisotropic in the wave-vector space with the major power having its wave-vector highly oblique to the ambient magnetic field, suggesting that the turbulence is quasi-2D. The measured "dispersion relations" obtained using the k-filtering technique are compared with theory and are found to be consistent with the Alfvén-Whistler mode. In addition, both Probability Distribution Functions and flatness results show that the turbulence in the reconnection jet is intermittent (multifractal) at scales less than the proton gyroradius/inertial lengths. The estimated electric field provided by anomalous resistivity caused by turbulence is about 3mV/m, which is close to the typical reconnection electric field in the magnetotail. © 2012. American Geophysical Union. All Rights Reserved.

Kiyani K.H.,Imperial College London | Kiyani K.H.,University of Warwick | Chapman S.C.,University of Warwick | Sahraoui F.,Laboratoire Of Physique Des Plasmas | And 4 more authors.
Astrophysical Journal | Year: 2013

The anisotropic nature of solar wind magnetic turbulence fluctuations is investigated scale by scale using high cadence in situ magnetic field measurements from the Cluster and ACE spacecraft missions. The data span five decades in scales from the inertial range to the electron Larmor radius. In contrast to the inertial range, there is a successive increase toward isotropy between parallel and transverse power at scales below the ion Larmor radius, with isotropy being achieved at the electron Larmor radius. In the context of wave-mediated theories of turbulence, we show that this enhancement in magnetic fluctuations parallel to the local mean background field is qualitatively consistent with the magnetic compressibility signature of kinetic Alfvén wave solutions of the linearized Vlasov equation. More generally, we discuss how these results may arise naturally due to the prominent role of the Hall term at sub-ion Larmor scales. Furthermore, computing higher-order statistics, we show that the full statistical signature of the fluctuations at scales below the ion Larmor radius is that of a single isotropic globally scale-invariant process distinct from the anisotropic statistics of the inertial range. © 2013. The American Astronomical Society. All rights reserved.

Agapitov O.,University of Orleans | Agapitov O.,Taras Shevchenko National University | Krasnoselskikh V.,University of Orleans | Zaliznyak Y.,University of Orleans | And 4 more authors.
Annales Geophysicae | Year: 2010

Discrete ELF/VLF chorus emissions, the most intense electromagnetic plasma waves observed in the Earth's radiation belts and outer magnetosphere, are thought to propagate roughly along magnetic field lines from a localized source region near the magnetic equator towards the magnetic poles. THEMIS project Electric Field Instrument (EFI) and Search Coil Magnetometer (SCM) measurements were used to determine the spatial scale of the chorus source localization region on the day side of the Earth's outer magnetosphere. We present simultaneous observations of the same chorus elements registered onboard several THEMIS spacecraft in 2007 when all the spacecraft were in the same orbit. Discrete chorus elements were observed at 0.15-0.25 of the local electron gyrofrequency, which is typical for the outer magnetosphere. We evaluated the Poynting flux and wave vector distribution and obtained chorus wave packet quasi-parallel propagation to the local magnetic field. Amplitude and phase correlation data analysis allowed us to estimate the characteristic spatial correlation scale transverse to the local magnetic field to be in the 2800-3200 km range. © 2010 Author(s).

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