Excitation of large-scale plasma sheets and micropulsations by injected high power radio waves

2011 ◽  
Author(s):  
M.C. Lee ◽  
R. Pradipta ◽  
J.A. Cohen ◽  
J. Morton ◽  
B.J. Watkins ◽  
...  
Keyword(s):  
High Power ◽  
Large Scale ◽  
Radio Waves ◽  
Plasma Sheets

Peculiarities of Excitation of Large-Scale Plasma Density Irregularities During Modification of the Ionospheric F 2 Region by High-Power HF Radio Waves

2016 ◽  
Vol 58 (10) ◽  
pp. 717-728 ◽  
Author(s):  
V. L. Frolov ◽  
E. A. Schorokhova ◽  
V. E. Kunitsyn ◽  
E. S. Andreeva ◽  
A. M. Padokhin
Keyword(s):  
Plasma Density ◽  
High Power ◽  
Large Scale ◽  
Radio Waves

scholarly journals Simulation study of the large-scale modification of the mid-latitude F-layer by HF radio waves with different powers

2012 ◽  
Vol 30 (8) ◽  
pp. 1213-1222 ◽  
Author(s):  
G. I. Mingaleva ◽  
V. S. Mingalev ◽  
O. V. Mingalev
Keyword(s):  
Mathematical Model ◽  
Simulation Study ◽  
High Power ◽  
Large Scale ◽  
Radio Waves ◽  
Effective Frequency ◽  
Heating Facility ◽  
Absorbed Power

Abstract. A mathematical model of the ionosphere, developed earlier, is applied to investigate the large-scale mid-latitude F-layer modification by HF radio waves with different powers. Simulations are performed for the point with geographic coordinates of the "Sura" heating facility (Nizhny Novgorod, Russia) for autumn conditions. The calculations are made for distinct cases, in which the effective absorbed power has different values belonging to the 5–100 MW range, both for nocturnal and daytime conditions. The frequency of powerful HF waves is chosen to be close to the most effective frequency for the large-scale F2-layer modification. The results of modeling indicate that the effective absorbed power can influence considerably the F-layer response to high-power radio waves in the mid-latitude ionosphere.

EISCAT observations of large scale electron temperture and electron density perturbations caused by high power HF radio waves

1992 ◽  
Vol 54 (11-12) ◽  
pp. 1555-1572 ◽  
Author(s):  
A.J. Stocker ◽  
F. Honary ◽  
T.R. Robinson ◽  
T.B. Jones ◽  
P. Stubbe ◽  
...  
Keyword(s):  
Electron Density ◽  
High Power ◽  
Large Scale ◽  
Radio Waves ◽  
Density Perturbations

scholarly journals Simulation study of the high-latitude F-layer modification by powerful HF waves with different frequencies for autumn conditions

2003 ◽  
Vol 21 (8) ◽  
pp. 1827-1838 ◽  
Author(s):  
G. I. Mingaleva ◽  
V. S. Mingalev ◽  
I. V. Mingalev
Keyword(s):  
Numerical Model ◽  
High Power ◽  
High Latitude ◽  
Large Scale ◽  
Plasma Temperature ◽  
Radio Waves ◽  
Active Experiments ◽  
F Region ◽  
Modeling And Forecasting ◽  
High Latitude Ionosphere

Abstract. The large-scale high-latitude F-region modification by high power radio waves is investigated using a numerical model of the convecting high-latitude ionosphere developed earlier. Simulations are performed for the point with geographic coordinates of the ionospheric heater near Tromsø, Scandinavia for autumn conditions. The calculations are made for distinct cases, in which high power waves have different frequencies, both for nocturnal and for day-time conditions. The results of modeling indicate that the frequency of HF waves ought to influence significantly the large-scale F-region modification by high power radio waves in the high-latitude ionosphere.Key words. Ionosphere (active experiments; modeling and forecasting; plasma temperature and density)

scholarly journals Nitrogen-enriched graphene framework from a large-scale magnesiothermic conversion of CO2 with synergistic kinetics for high-power lithium-ion capacitors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Chen Li ◽  
Xiong Zhang ◽  
Kai Wang ◽  
Xianzhong Sun ◽  
Yanan Xu ◽  
...  
Keyword(s):  
Energy Density ◽  
High Power ◽  
Power Output ◽  
Large Scale ◽  
Electrode Materials ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Chemical Doping ◽  
Lithium Ion Capacitor

AbstractLithium-ion capacitors are envisaged as promising energy-storage devices to simultaneously achieve a large energy density and high-power output at quick charge and discharge rates. However, the mismatched kinetics between capacitive cathodes and faradaic anodes still hinder their practical application for high-power purposes. To tackle this problem, the electron and ion transport of both electrodes should be substantially improved by targeted structural design and controllable chemical doping. Herein, nitrogen-enriched graphene frameworks are prepared via a large-scale and ultrafast magnesiothermic combustion synthesis using CO2 and melamine as precursors, which exhibit a crosslinked porous structure, abundant functional groups and high electrical conductivity (10524 S m−1). The material essentially delivers upgraded kinetics due to enhanced ion diffusion and electron transport. Excellent capacities of 1361 mA h g−1 and 827 mA h g−1 can be achieved at current densities of 0.1 A g−1 and 3 A g−1, respectively, demonstrating its outstanding lithium storage performance at both low and high rates. Moreover, the lithium-ion capacitor based on these nitrogen-enriched graphene frameworks displays a high energy density of 151 Wh kg−1, and still retains 86 Wh kg−1 even at an ultrahigh power output of 49 kW kg−1. This study reveals an effective pathway to achieve synergistic kinetics in carbon electrode materials for achieving high-power lithium-ion capacitors.

Changing ionization of the lower ionosphere due to high-power radio waves

1977 ◽  
Vol 20 (12) ◽  
pp. 1230-1239 ◽  
Author(s):  
A. V. Gurevich ◽  
G. M. Milikh ◽  
I. S. Shlyuger
Keyword(s):  
High Power ◽  
Lower Ionosphere ◽  
Radio Waves

scholarly journals Suppression of amplitude modulation induced by polarization mode dispersion using a multi-degree-of-freedom fiber filter

2018 ◽  
Vol 6 ◽  
Author(s):  
Rao Li ◽  
Youen Jiang ◽  
Zhi Qiao ◽  
Canhong Huang ◽  
Wei Fan ◽  
...  
Keyword(s):  
High Power ◽  
Amplitude Modulation ◽  
Transmission Spectrum ◽  
High Speed ◽  
Large Scale ◽  
Modulation Depth ◽  
Free Spectral Range ◽  
Polarization Mode Dispersion ◽  
Polarization Mode ◽  
Mode Dispersion

Polarization mode dispersion (PMD) in fibers for high-power lasers can induce significant frequency modulation to amplitude modulation (FM-to-AM) conversion. However, existing techniques are not sufficiently flexible to achieve efficient compensation for such FM-to-AM conversion. By analyzing the nonuniform transmission spectrum caused by PMD, we found that the large-scale envelope of the transmission spectrum has more serious impacts on the amount of AM. In order to suppress the PMD-induced FM-to-AM conversion, we propose a novel tunable spectral filter with multiple degrees of freedom based on a half-wave plate, a nematic liquid crystal, and an axis-rotated polarization-maintaining fiber. Peak wavelength, free spectral range (FSR), and modulation depth of the filter are decoupled and can be controlled independently, which is verified through both simulations and experiments. The filter is utilized to compensate for the PMD-induced FM-to-AM conversion in the front end of a high-power laser facility. The results indicate that, for a pulse with phase-modulation frequency of 22.82 GHz, the FM-to-AM conversion could be reduced from 18% to 3.2% within a short time and maintained below 6.5% for 3 h. The proposed filter is also promising for other applications that require flexible spectral control such as high-speed channel selection in optical communication networks.

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