Ion Current to a Langmuir Probe in Very Low Density Flowing Plasmas for Electron‐Density Determinations

1968 ◽  
Vol 39 (7) ◽  
pp. 3300-3305 ◽  
Author(s):  
Sin‐Li Chen ◽  
J. M. Goodings
Keyword(s):  
Electron Density ◽  
Langmuir Probe ◽  
Ion Current ◽  
Low Density

Plasmaspheric response to the geomagnetic storm period March 20–23, 1990, observed by the ACTIVNY (MAGION-2) satellite

1992 ◽  
Vol 70 (7) ◽  
pp. 569-574 ◽  
Author(s):  
M. Förster ◽  
N. Jakowski ◽  
A. Best ◽  
J. Smilauer
Keyword(s):  
Magnetic Storm ◽  
Electron Density ◽  
Geomagnetic Storm ◽  
Joule Heating ◽  
Growth Phase ◽  
Langmuir Probe ◽  
Atomic Oxygen ◽  
Scale Height ◽  
Ionospheric Response ◽  
Increased Pressure

Langmuir probe data obtained during the storm period March 20–23, 1990, on board the MAGION-2 subsatellite of the ACTIVNY experiment are analyzed to study the plasmaspheric and ionospheric response to a magnetic storm. The data indicate a well-pronounced equatorward edge of the electron density trough in the afternoon (18:15 LT) at about 800 km height that moves towards lower latitudes during the course of the storm. It is interesting to note that the electron density inside the plasmasphere is increased by more than 20% in the morning shortly after sunrise (07:30 LT). This is due to enhanced O+ densities in the lower plasmasphere during the growth phase of the geomagnetic storm as measured by the ion mass spectrometer NAM-5 onboard the main satellite. It is suggested that the source for the increased density is thermospheric Joule heating at auroral latitudes with a commensurate increase in thermospheric pressure. This increased pressure causes the local thermosphere to expand both upward and equatorward. The increased atomic-oxygen scale height coupled with equatorward motion of fhermospheric perturbations results in an increased O density and resulting O+ density within the lower plasmasphere. The observations indicate a storm-induced compression of the plasmasphere that favourizes an enhanced outflow of plasma into the ionosphere leading to an increased nighttime F2-layer ionization and a depletion of the plasmasphere during the following hours.

scholarly journals Diagnostics of low-pressure capacitively coupled RF discharge argon plasma

2019 ◽  
Vol 13 (27) ◽  
pp. 76-82
Author(s):  
Kadhim A. Aadim
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Langmuir Probe ◽  
Gas Flow ◽  
Low Pressure ◽  
Gas Pressure ◽  
Rf Discharge ◽  
Electrode Gap ◽  
Probe Characteristic ◽  
Capacitively Coupled

Low-pressure capacitively coupled RF discharge Ar plasma has been studied using Langmuir probe. The electron temperature, electron density and Debay length were calculated under different pressures and electrode gap. In this work the RF Langmuir probe is designed using 4MHz filter as compensation circuit and I-V probe characteristic have been investigated. The pressure varied from 0.07 mbar to 0.1 mbar while electrode gap varied from 2-5 cm. The plasma was generated using power supply at 4MHz frequency with power 300 W. The flowmeter is used to control Argon gas flow in the range of 600 standard cubic centimeters per minute (sccm). The electron temperature drops slowly with pressure and it's gradually decreased when expanding the electrode gap. As the gas pressure increases, the plasma density rises slightly at low gas pressure while it drops little at higher gas pressure. The electron density decreases rapidly with expand distances between electrodes.

A transmission-type triple grating spectrograph for improved laser scattering diagnostics of low-density plasmas used in chemical analysis

2020 ◽  
Vol 35 (9) ◽  
pp. 1932-1946
Author(s):  
Kevin Finch ◽  
Aldo Hernandez ◽  
Yue She ◽  
Songyue Shi ◽  
Gerardo Gamez
Keyword(s):  
Detection Limit ◽  
Chemical Analysis ◽  
Electron Density ◽  
Measurement Time ◽  
Low Density ◽  
Laser Scattering ◽  
Plasma Species

An improved transmission-type triple grating spectrograph permits 2D mapping of plasma species via laser scattering closer to surfaces, at faster measurement time, and the lowest electron density detection limit reported.

scholarly journals Identifying possible Stratification phenomenon in ionospheric F2 Layer using the data observed by the Demeter satellite: Method and Results

2019 ◽  
Author(s):  
Xiuying Wang ◽  
Dehe Yang ◽  
Dapeng Liu ◽  
Wei Chu
Keyword(s):  
Statistical Method ◽  
Electron Density ◽  
Langmuir Probe ◽  
Geomagnetic Equator ◽  
Density Data ◽  
Demeter Satellite ◽  
Summer Hemisphere ◽  
First Time ◽  
Different Altitudes

Abstract. Many studies have revealed the stratification phenomenon of the topside ionospheric F2 layer using ground-based or satellite-based ionograms, which can show direct signs of this phenomenon. However, it is difficult to identify this phenomenon using the satellite-based in situ electron density data. Therefore, a statistical method, using the shuffle resampling skill, is adopted in this paper. For the first time, in situ electron density data, recorded by the same Langmuir probe onboard the Demeter satellite at different altitudes, are analyzed and a possible stratification phenomenon is identified using the proposed method. Our results show that the nighttime stratification, possibly a permanent phenomenon, can cover most longitudes near the geomagnetic equator, which is not found from the daytime data. The arch-like nighttime stratification decreases slowly on the summer hemisphere and thus extends a larger latitudinal distance from the geomagnetic equator. All results, obtained by the proposed method, indicate that the stratification phenomenon is more complex than what has previously been found. The proposed method thus is an effective one, which can also be used on similar studies of comparing fluctuated data.

scholarly journals Identifying a possible stratification phenomenon in ionospheric F2 layer using the data observed by the DEMETER satellite: method and results

2019 ◽  
Vol 37 (4) ◽  
pp. 645-655 ◽  
Author(s):  
Xiuying Wang ◽  
Dehe Yang ◽  
Dapeng Liu ◽  
Wei Chu
Keyword(s):  
Electron Density ◽  
Langmuir Probe ◽  
Geomagnetic Equator ◽  
Density Data ◽  
Demeter Satellite ◽  
Summer Hemisphere ◽  
Electro Magnetic ◽  
First Time ◽  
Different Altitudes

Abstract. Many studies have revealed the stratification phenomenon of the topside ionospheric F2 layer using ground-based or satellite-based ionograms, which can show direct signs of this phenomenon. However, it is difficult to identify this phenomenon using the satellite-based in situ electron density data. Therefore, a statistical method, using the shuffle resampling skill, is adopted in this paper. For the first time, in situ electron density data, recorded by the same Langmuir probe aboard the DEMETER (Detection of Electro-Magnetic Emission Transmitted from Earthquake Regions) satellite at different altitudes, are analyzed, and a possible stratification phenomenon is identified using the proposed method. Our results show that the nighttime stratification, possibly a permanent phenomenon, can cover most longitudes near the geomagnetic equator, which is not found from the daytime data. The arch-like nighttime stratification decreases slowly on the summer hemisphere and thus extends a larger latitudinal distance from the geomagnetic equator. All results, obtained by the proposed method, indicate that the stratification phenomenon is more complex than what has previously been found. The proposed method is thus an effective one, which can also be used in similar studies of comparing fluctuated data.

New algorithms to estimate electron temperature and electron density with contaminated DC Langmuir probe onboard CubeSat

2020 ◽  
Vol 66 (1) ◽  
pp. 148-161
Author(s):  
Shyh-Biau Jiang ◽  
Tse-Liang Yeh ◽  
Jann-Yenq Liu ◽  
Chi-Kuang Chao ◽  
Loren C. Chang ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Langmuir Probe ◽  
New Algorithms

Multi-Needle Langmuir Probe System for Electron Density Measurements and Active Spacecraft Potential Control on CubeSats

2019 ◽  
Vol 55 (6) ◽  
pp. 2951-2964 ◽  
Author(s):  
Tore Andre Bekkeng ◽  
Espen Sorlie Helgeby ◽  
Arne Pedersen ◽  
Espen Trondsen ◽  
Torfinn Lindem ◽  
...  
Keyword(s):  
Electron Density ◽  
Langmuir Probe ◽  
Density Measurements ◽  
Potential Control ◽  
Spacecraft Potential ◽  
Probe System
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