scholarly journals Dayside electron temperature and density profiles at Mars: First results from the MAVEN Langmuir probe and waves instrument

2015 ◽  
Vol 42 (21) ◽  
pp. 8846-8853 ◽  
Author(s):  
R. E. Ergun ◽  
M. W. Morooka ◽  
L. A. Andersson ◽  
C. M. Fowler ◽  
G. T. Delory ◽  
...  
2021 ◽  
Author(s):  
Sylvain Ranvier ◽  
Johan De Keyser ◽  
Jean-Pierre Lebreton

<p>The Sweeping Langmuir Probe (SLP) instrument on board the Pico-Satellite for Atmospheric and Space Science Observations (PICASSO) has been developed at the Royal Belgian Institute for Space Aeronomy.  PICASSO, an ESA in-orbit demonstrator launched in September 2020, is a triple unit CubeSat orbiting at about 540 km altitude with 97 degrees inclination. The SLP instrument includes four independent cylindrical probes that are used to measure the plasma density and electron temperature as well as the floating potential of the spacecraft. Along the orbit of PICASSO the plasma density is expected to fluctuate over a wide range, from about 1e8/m<sup>3</sup> at high latitude up to more than 1e12/m<sup>3</sup> at low/mid latitude. SLP can measure plasma density from 1e8/m<sup>3</sup> to 1e13/m<sup>3</sup>. The electron temperature is expected to lie between approximately 1000 K and 10.000 K. Given the high inclination of the orbit, SLP will allow a global monitoring of the ionosphere. Using the traditional sweeping mode, the maximum spatial resolution is of the order of a few hundred meters for the plasma density, electron temperature and spacecraft potential. With the fixed-bias mode, the electron density can be measured with a spatial resolution of about 1.5 m. The main goals are to study the ionosphere-plasmasphere coupling, the subauroral ionosphere and corresponding magnetospheric features together with auroral structures and polar caps, by combining SLP data with other complementary data sources (space- or ground-based instruments). The first results from SLP will be presented.</p>


2019 ◽  
Vol 13 (27) ◽  
pp. 76-82
Author(s):  
Kadhim A. Aadim

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.


2008 ◽  
Vol 26 (3) ◽  
pp. 533-541 ◽  
Author(s):  
K.-I. Oyama ◽  
T. Abe ◽  
H. Mori ◽  
J. Y. Liu

Abstract. Electron temperature in the sporadic E layer was measured with a glass-sealed Langmuir probe at a mid-latitude station in Japan in the framework of the SEEK (Sporadic E Experiment over Kyushu)-2 campaign which was conducted in August 2002. Important findings are two fold: (1) electron temperature and electron density vary in the opposite sense in the height range of 100–108 km, and electron temperature in the Es layer is lower than that of ambient plasma, (2) electron temperature in these height ranges is higher than the possible range of neutral temperature. These findings strongly suggest that the heat source that elevates electron temperature much higher than possible neutral temperature exists at around 100 km, and/or that the physical parameter values, which are used in the present theory to calculate electron temperature, are not proper.


Plasma ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 229-241 ◽  
Author(s):  
Manjit Kaur ◽  
Kaitlin Gelber ◽  
Adam Light ◽  
Michael Brown

We describe ion and electron temperature measurements in the Swarthmore Spheromak Experiment (SSX) MHD wind tunnel with the goal of understanding limitations on the lifetime of our Taylor-state plasma. A simple model based on the equilibrium eigenvalue and Spitzer resistivity predicted the lifetime satisfactorily during the first phase of the plasma evolution. We measured an average T e along a chord by taking the ratio of the C I I I 97.7 nm to C I V 155 nm line intensities using a vacuum ultraviolet (VUV) monochromator. We also recorded local measurements of T e and n e using a double Langmuir probe in order to inform our interpretation of the VUV data. Our results indicated that the plasma decayed inductively during a large part of the evolution. Ion Doppler spectroscopy measurements suggested that ions cooled more slowly than would be expected from thermal equilibration with the electrons, which maintained a constant temperature throughout the lifetime of the plasma.


2020 ◽  
Vol 66 (1) ◽  
pp. 148-161
Author(s):  
Shyh-Biau Jiang ◽  
Tse-Liang Yeh ◽  
Jann-Yenq Liu ◽  
Chi-Kuang Chao ◽  
Loren C. Chang ◽  
...  

2018 ◽  
Vol 2 (6) ◽  
pp. 1-10 ◽  
Author(s):  
Rui Yan ◽  
◽  
YiBing Guan ◽  
XuHui Shen ◽  
JianPing Huang ◽  
...  

2013 ◽  
Vol 347-350 ◽  
pp. 55-58
Author(s):  
Yong Li ◽  
Rui Zhang ◽  
Jian Hua Zong

A current-model Triple Langmuir probe was developed and used to measure electron temperature and density of the Pulsed Plasma Thruster plume. To decreasing the errors in measurement, Probe, collection circuit and glow cleaning devices were elaborately designed. A FIR digital Filter based on Matlab was designed and the software for date processing was developed by Labview. Measurements were taken at various position in the plume of a Pulsed Plasma Thruster operating at discharge energy of 6-24J. The results show the thruster plume has electron temperatures in the range between 0.6and 5.4eV, electron densities between 0.9×1019 and 4.1x1021m-3 for all discharge energy levels considered. Electron temperature and density decrease with increasing angle away from the centerline and with decreasing discharge energy.


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