The first in situ electron temperature and density measurements of the Martian nightside ionosphere

We present a non-invasive approach for monitoring plasma parameters such as the electron temperature and density inside a radio-frequency (RF) plasma nitridation device using optical emission spectroscopy (OES) in conjunction with multivariate data analysis. Instead of relying on a theoretical model of the plasma emission to extract plasma parameters from the OES, an empirical correlation was established on the basis of simultaneous OES and other diagnostics. Additionally, we developed a machine learning (ML)-based virtual metrology model for real-time Te and ne monitoring in plasma nitridation processes using an in situ OES sensor. The results showed that the prediction accuracy of electron density was 97% and that of electron temperature was 90%. This method is especially useful in plasma processing because it provides in-situ and real-time analysis without disturbing the plasma or interfering with the process.

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PICASSO: The Golden CubeSat

10.5194/egusphere-egu21-15865 ◽

2021 ◽

Author(s):

Noel Baker ◽

Michel Anciaux ◽

Philippe Demoulin ◽

Didier Fussen ◽

Didier Pieroux ◽

...

Keyword(s):

Electron Temperature ◽

Plasma Density ◽

Space Science ◽

Lessons Learned ◽

Vertical Profiles ◽

Proof Of Concept ◽

Scientific Instruments ◽

The Earth ◽

Spacecraft Potential

<p>Led by the Belgian Institute for Space Aeronomy, the ESA-backed mission PICASSO (PICo-Satellite for Atmospheric and Space Science Observations) successfully launched its gold-plated satellite on an Arianespace Vega rocket in September 2020. PICASSO is a 3U CubeSat mission in collaboration with VTT Technical Research Center of Finland Ltd, AAC Clyde Space Ltd. (UK), and the CSL (Centre Spatial de Li&#232;ge), Belgium. The commissioning of the two onboard scientific instruments is currently ongoing; once they are operational, PICASSO will be capable of providing scientific measurements of the Earth&#8217;s atmosphere. VISION, proposed by BISA and developed by VTT, will retrieve vertical profiles of ozone and temperature by observing the Earth's atmospheric limb during orbital Sun occultation; and SLP, developed by BISA, will measure in situ plasma density and electron temperature together with the spacecraft potential.</p><p>Serving as a groundbreaking proof-of-concept, the PICASSO mission has taught valuable lessons about the advantages of CubeSat technology as well as its many complexities and challenges. These lessons learned, along with preliminary measurements from the two instruments, will be presented and discussed.</p>

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In situ observation of electron temperature enhancement inside equatorial plasma bubbles

10.3997/2214-4609-pdb.168.arq_2006 ◽

2003 ◽

Author(s):

P. Muralikrishna

Keyword(s):

Electron Temperature ◽

In Situ Observation ◽

Plasma Bubbles ◽

Equatorial Plasma Bubbles ◽

Temperature Enhancement

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Density structures inside the plasmasphere: Cluster observations

Annales Geophysicae ◽

10.5194/angeo-22-2577-2004 ◽

2004 ◽

Vol 22 (7) ◽

pp. 2577-2585 ◽

Cited By ~ 35

Author(s):

F. Darrouzet ◽

P. M. E. Décréau ◽

J. De Keyser ◽

A. Masson ◽

D. L. Gallagher ◽

...

Keyword(s):

Density Gradient ◽

Time Delays ◽

Statistical Study ◽

Outer Boundary ◽

Normal Velocity ◽

Density Profiles ◽

Density Measurements ◽

Image Satellite ◽

Electron Density Profiles

Abstract. The electron density profiles derived from the EFW and WHISPER instruments on board the four Cluster spacecraft reveal density structures inside the plasmasphere and at its outer boundary, the plasmapause. We have conducted a statistical study to characterize these density structures. We focus on the plasmasphere crossing on 11 April 2002, during which Cluster observed several density irregularities inside the plasmasphere, as well as a plasmaspheric plume. We derive the density gradient vectors from simultaneous density measurements by the four spacecraft. We also determine the normal velocity of the boundaries of the plume and of the irregularities from the time delays between those boundaries in the four individual density profiles, assuming they are planar. These new observations yield novel insights about the occurrence of density irregularities, their geometry and their dynamics. These in-situ measurements are compared with global images of the plasmasphere from the EUV imager on board the IMAGE satellite.

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First electron temperature and density measurements of D-module plasma in GAMMA 10/PDX using Thomson scattering and microwave interferometer systems

Journal of Instrumentation ◽

10.1088/1748-0221/14/06/p06033 ◽

2019 ◽

Vol 14 (06) ◽

pp. P06033-P06033

Author(s):

M. Yoshikawa ◽

J. Kohagura ◽

Y. Shima ◽

H. Nakanishi ◽

T. Mouri ◽

...

Keyword(s):

Electron Temperature ◽

Thomson Scattering ◽

Density Measurements

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Overview of the ECE measurements on EAST

EPJ Web of Conferences ◽

10.1051/epjconf/201920303008 ◽

2019 ◽

Vol 203 ◽

pp. 03008

Author(s):

Yong Liu ◽

Hailin Zhao ◽

Tianfu Zhou ◽

Xiang Liu ◽

Zeying Zhu ◽

...

Keyword(s):

Electron Temperature ◽

Michelson Interferometer ◽

Absolute Intensity ◽

Antenna System ◽

Optical Antenna ◽

Plasma Emission ◽

Vacuum Vessel ◽

Simulation Code ◽

Cyclotron Emission

Radiometer systems and a Michelson interferometer, have been operated routinely to detect the elec-tron cyclotron emission (ECE) from EAST plasmas for diagnosing the local electron temperature. A common quasi-optical antenna placed inside the vacuum vessel is employed to collect and focus the plasma emission, and the line of sight is along a radial chord. All of the systems are located in a diagnostic room where the plasma emission is transmitted by overmoded corrugated waveguide. In-situ absolute intensity calibration has been carried out for both the radiometer systems and the Michelson interferometer independently, to ensure that the ECE diagnostic provides an independent electron temperature measurement. In order to diagnose the small-amplitude electron temperature fluctuation, a correlation ECE (CECE) diagnostic has been designed and commissioned recently. The CECE diagnostic employs an independent antenna system which has improved poloidal resolution. A synthetic diagnostic is realized by using the simulation code SPECE to interpret the ECE data in plasmas with non-Maxwellian distribution, and preliminary results imply that the ECE data could be still useful as a localized measurement in plasmas with non-thermal electrons, such as the LHW-heated plasmas on EAST.

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Stratification observed by the in situ plasma density measurements from the Swarm satellites

Annales Geophysicae ◽

10.5194/angeo-38-517-2020 ◽

2020 ◽

Vol 38 (2) ◽

pp. 517-526

Author(s):

Xiuying Wang ◽

Wanli Cheng ◽

Zihan Zhou ◽

Dehe Yang ◽

Jing Cui ◽

...

Keyword(s):

Plasma Density ◽

Continuous Distribution ◽

Direct Analysis ◽

Density Measurements ◽

Equatorial Ionization Anomaly ◽

Swarm Satellites ◽

Plasma Peak ◽

First Time ◽

New Discovery

Abstract. The stratification phenomenon is investigated using the simultaneous in situ plasma density measurements obtained by the Swarm satellites orbiting at different altitudes above the F2 peak. For the first time, the continuous distribution morphology and the exact locations are obtained for the nighttime stratification, which show that the stratification events are centered at the EIA (equatorial ionization anomaly) trough and extend towards the two EIA crests, with the most significant part being located at the EIA trough. Another new discovery is the stratification in southern mid-latitudes; stratification events in this region are located on a local plasma peak sandwiched by two lower density strips covering all the longitudes. The formation mechanism of the stratification for the two latitudinal regions is discussed, but the stratification mechanism in southern mid-latitudes remains an unsolved problem. Highlights. This paper addresses the following: first application of in situ plasma densities for the direct analysis of the stratification in F2 layer, refined features of the exact location and continuous morphology for the stratification phenomenon, a new discovery of stratification covering all longitudes in southern mid-latitudes.

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Stratification observed by the in situ measurements from the Swarm satellites

10.5194/angeo-2019-161 ◽

2020 ◽

Author(s):

Xiuying Wang ◽

Wanli Cheng ◽

Zihan Zhou ◽

Dehe Yang ◽

Jing Cui ◽

...

Keyword(s):

Unsolved Problem ◽

Continuous Distribution ◽

Density Measurements ◽

Equatorial Ionization Anomaly ◽

Swarm Satellites ◽

Plasma Peak ◽

First Time ◽

Different Altitudes ◽

New Discovery

Abstract. Stratification phenomenon is investigated using the simultaneous in situ plasma density measurements obtained by the Swarm satellites orbiting at different altitudes above F2 peak. For the first time, the continuous distribution morphology and the exact locations are obtained for the nighttime stratification, which show that the stratification events are centered at the EIA (equatorial ionization anomaly) trough and extend towards the two EIA crests with the most significant part being located at the EIA trough. Another new discovery is the stratification in southern mid-latitudes; stratification events in this region are located on a local plasma peak sandwiched by two lower density strips covering all the longitudes. The formation mechanism of the stratification for the two latitudinal regions is discussed, but the stratification mechanism in southern mid-latitudes remains an unsolved problem.

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