scholarly journals Ionospheric anomalies associated with the Haiti earthquake of 12 January 2010 observed by DEMETER satellite

2012 ◽  
Vol 12 (3) ◽  
pp. 671-678 ◽  
Author(s):  
S. Sarkar ◽  
S. Choudhary ◽  
A. Sonakia ◽  
A. Vishwakarma ◽  
A. K. Gwal
Keyword(s):  
Electron Temperature ◽  
Satellite Data ◽  
Strong Earthquake ◽  
Plasma Parameter ◽  
Statistical Processing ◽  
Haiti Earthquake ◽  
Plasma Parameters ◽  
Demeter Satellite ◽  
Parameter Variations ◽  
Precursory Phenomena

Abstract. This paper examines the ionospheric anomalies around the time of a strong earthquake (M = 7.0) which occurred in Haiti region (18.457° N, 72.533° W) on 12 January 2010. DEMETER satellite data have been used to study the plasma parameters variation during the Haiti earthquake. One day (11 January 2010) before the earthquake there is a significant enhancement of electron density and electron temperature near the epicenter. Decrease of electron temperature is observed few days after the earthquake. Anomalous plasma parameter variations are detected both in day and nighttimes before the quake. Statistical processing of the DEMETER data demonstrates that satellite data can play an important role for the study of precursory phenomena associated with earthquakes.

Bayesian filtering for incoherent scatter radar analysis

2020 ◽  
Author(s):  
Habtamu Tesfaw ◽  
Ilkka Virtanen ◽  
Anita Aikio ◽  
Lassi Roininen ◽  
Sari Lasanen
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Time Resolution ◽  
Plasma Parameter ◽  
Temperature Profiles ◽  
Bayesian Filtering ◽  
Ion Composition ◽  
Ion Temperature ◽  
Plasma Parameters ◽  
Incoherent Scatter

<p>Electron precipitation and ion frictional heating events cause rapid variations in electron temperature, ion temperature and F1 region ion composition of the high-latitude ionosphere. Four plasma parameters: electron density, electron temperature, ion temperature, and plasma bulk velocity, are typically fitted to incoherent scatter radar (ISR) data.</p><p>Many ISR data analysis tools extract the plasma parameters using an ion composition profile from an empirical model. The modeled ion composition profile may cause bias in the estimated ion and electron temperature profiles in the F1 region, where both atomic and molecular ions exist with a temporally varying proportion.</p><p>In addition, plasma parameter estimation from ISR measurements requires integrating the scattered signal typically for tens of seconds. As a result, the standard ISR observations have not been able to follow the rapid variations in plasma parameters caused by small scale auroral activity.</p><p>In this project, we implemented Bayesian filtering technique to the EISCAT’s standard ISR data analysis package, GUISDAP. The technique allows us to control plasma parameter gradients in altitude and time.</p><p>The Bayesian filtering implementation enabled us to fit electron density, ion and electron temperatures, ion velocity and ion composition to ISR data with high time resolution. The fitted ion composition removes observed artifacts in ion and electron temperature estimates and the plasma parameters are calculated with 5 s time resolution which was previously unattainable.</p><p>Energy spectra of precipitating electrons can be calculated from electron density and electron temperature profiles observed with ISR. We used the unbiased high time-resolved electron density and temperature estimates to improve the accuracy of the estimated energy spectra. The result shows a significant difference compared to previously published results, which were based on the raw electron density (backscattered power) and electron temperature estimates calculated with coarser time resolution.</p><p> </p>

Measurement of Plasma Parameters of Fe-Lines in Lipstick Using Laser-Induced Breakdown Spectroscopy

2021 ◽  
Vol 19 (10) ◽  
pp. 01-07
Author(s):  
M.H. Asmaa ◽  
Sami A. Habana
Keyword(s):  
Electron Temperature ◽  
Debye Length ◽  
Nuclear Data ◽  
Laser Induced Breakdown Spectroscopy ◽  
Current Investigation ◽  
Plasma Parameters ◽  
Data Set ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Business Sectors

Electron thickness and temperature of laser prompted Iron plasma boundaries, among different boundaries, were estimated. Plasma was delivered through the connection of high pinnacle power Nd: YAG laser at the key frequency of 1064 nm with a pellet target contains a limited quantity of lipstick from nearby business sectors. Lines from Fe II at 238.502 nm, Fe II at 254.904 nm, Fe II at 262.370 nm, Fe II at 286.545 nm and Fe I at 349.779 nm were utilized to assess the plasma boundaries. The current investigation was completed to assess electron temperature (Te), electron thickness (ne), plasma recurrence, Debye length and Debye number (ND). Laser-incited breakdown spectroscopy LIBS method was used for examining and deciding ghastly discharge lines. ID of change lines from all spectra was completed by contrasting ghostly lines and NIST nuclear data set.

scholarly journals Effect of the gas puff location on the divertor plasma properties in COMPASS tokamak

2020 ◽  
Vol 1492 (1) ◽  
pp. 012003
Author(s):  
M Dimitrova ◽  
M Tomes ◽  
Tsv Popov ◽  
R Dejarnac ◽  
J Stockel ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Vacuum Chamber ◽  
Plasma Potential ◽  
Saturation Current ◽  
Langmuir Probes ◽  
Plasma Parameters ◽  
Plasma Properties ◽  
Low Field ◽  
Saturation Current Density ◽  
Deuterium Gas

Abstract Langmuir probes are used to study the plasma parameters in the divertor during deuterium gas puff injection on the high- (HFS) or low-field sides (LFS). The probe data were processed to evaluate the plasma potential and the electron temperatures and densities. A difference was found in the plasma parameters depending on the gas puff location. In the case of a gas puff on the LFS, the plasma parameters changed vastly, mainly in the inner divertor – the plasma potential, the ion saturation-current density and the electron temperature dropped. After the gas puff, the electron temperature changed from 10-15 eV down to within the 5-9 eV range. As a result, the parallel heat-flux density decreased. At the same time, in the outer divertor the plasma parameters remained the same. We thus concluded that using a gas puff on the LFS will facilitate reaching a detachment regime by increasing the density of puffed neutrals. When the deuterium gas puff was on the HFS, the plasma parameters in the divertor region remained almost the same before and during the puff. The electron temperature decreased with just few eV as a result of the increased amount of gas in the vacuum chamber.

scholarly journals Machine Learning Prediction of Electron Density and Temperature from Optical Emission Spectroscopy in Nitrogen Plasma

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1221
Author(s):  
Jun-Hyoung Park ◽  
Ji-Ho Cho ◽  
Jung-Sik Yoon ◽  
Jung-Ho Song
Keyword(s):  
Machine Learning ◽  
Electron Temperature ◽  
Real Time ◽  
Electron Density ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Plasma Parameters ◽  
Plasma Nitridation

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.

Laser-Induced Plasma Atomic and Ionic Emission During Target Ablation

2021 ◽  
Author(s):  
Nisreen Kh. Abdalameer ◽  
Sabah N. Mazhir
Keyword(s):  
Nd:Yag Laser ◽  
Plasma Parameter ◽  
Debye Length ◽  
Optical Emission ◽  
Solid Target ◽  
Plasma Parameters ◽  
Laser Induced Plasma ◽  
Repeat Rate ◽  
Ionic Emission ◽  
Debye Formula

This paper investigates the spectroscopy of plasma that resulted from the bombardment of ZnSe by using the optical emission spectroscopic (OES) technique. The plasma can be generated by the reaction between an Nd:YAG laser, with a wavelength of 1064[Formula: see text]nm with a repeat rate of 6[Formula: see text]Hz (as well as 9[Formula: see text]ns pulse duration), and a solid target, where the density of the electron (ne), the temperature of the electron ([Formula: see text]), the frequency of the plasma ([Formula: see text]) and the Debye length ([Formula: see text]) as plasma parameters, in addition to the particles’ number of Debye ([Formula: see text]) and plasma parameter ([Formula: see text]) have been calculated by picking up the spectrum of plasma at different energies (100, 200, 300, 400, 500) mj using Selenium (Se), Zinc (Zn) and the mixture (ZnSe) at ([Formula: see text]). It is found that the electron temperatures of Zn and Se ranged between (0.257–0.267)[Formula: see text]eV and (1.036–1.055) eV, respectively, while that of ZnSe ranged between (1.15–1.28)[Formula: see text]eV. This indicates that the electron temperature of ZnSe is higher than the temperatures of each Zn and Se.

scholarly journals Thermal, atmospheric and ionospheric anomalies around the time of the Colima M7.8 earthquake of 21 January 2003

2006 ◽  
Vol 24 (3) ◽  
pp. 835-849 ◽  
Author(s):  
S. A. Pulinets ◽  
D. Ouzounov ◽  
L. Ciraolo ◽  
R. Singh ◽  
G. Cervone ◽  
...  
Keyword(s):  
Latent Heat ◽  
Strong Earthquake ◽  
Statistical Processing ◽  
Water Molecules ◽  
Electron Content ◽  
Atmospheric Parameters ◽  
Main Attention ◽  
Total Electron ◽  
Surface Latent Heat Flux ◽  
Relationship Of

Abstract. The paper examines the possible relationship of anomalous variations of different atmospheric and ionospheric parameters observed around the time of a strong earthquake (Mw 7.8) which occurred in Mexico (state of Colima) on 21 January 2003. These variations are interpreted within the framework of the developed model of the Lithosphere-Atmosphere-Ionosphere coupling. The main attention is focused on the processes in the near ground layer of the atmosphere involving the ionization of air by radon, the water molecules' attachment to the formed ions, and the corresponding changes in the latent heat. Model considerations are supported by experimental measurements showing the local diminution of air humidity one week prior to the earthquake, accompanied by the anomalous thermal infrared (TIR) signals and surface latent heat flux (SLHF) and anomalous variations of the total electron content (TEC) registered over the epicenter of the impending earthquake three days prior to the main earthquake event. Statistical processing of the data of the GPS receivers network, together with various other atmospheric parameters demonstrate the possibility of an early warning of an impending strong earthquake.

scholarly journals Magnetic field effect on laser-induced breakdown spectroscopy and surface modifications of germanium at various fluences

2017 ◽  
Vol 35 (1) ◽  
pp. 159-169 ◽  
Author(s):  
H. Iftikhar ◽  
S. Bashir ◽  
A. Dawood ◽  
M. Akram ◽  
A. Hayat ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Temperature ◽  
Surface Modifications ◽  
Laser Induced Breakdown Spectroscopy ◽  
Excitation Temperature ◽  
Number Density ◽  
Plasma Parameters ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
The Magnetic Field

AbstractThe effect of the transverse magnetic field on laser-induced breakdown spectroscopy and surface modifications of germanium (Ge) has been investigated at various fluences. Ge targets were exposed to Nd: YAG laser pulses (1064 nm, 10 ns, 1 Hz) at different fluences ranging from 3 to 25.6 J/cm2 to generate Ge plasma under argon environment at a pressure of 50 Torr. The magnetic field of strength 0.45 Tesla perpendicular to the direction of plasma expansion was employed by using two permanent magnets. The emission spectra of laser-induced Ge plasma was detected by the laser-induced breakdown spectroscopy system. The electron temperature and number density of Ge plasma are evaluated by using the Boltzmann plot and stark broadening methods, respectively. The variations in emission intensity, electron temperature (Te), and number density (ne) of Germanium plasma are explored at various fluences, with and without employment of the magnetic field. It is observed that the magnetic field is responsible for significant enhancement of both excitation temperature and number density at all fluences. It is revealed that an excitation temperature increases from Te,max,without B = 16,190 to Te,max,with B = 20,123 K. Similarly, the two times enhancement in the electron density is observed from ne,max,without B = 2 × 1018 to ne,max,with B = 4 × 1018 cm−3. The overall enhancement in Ge plasma parameters in the presence of the magnetic field is attributed to the Joule heating effect and adiabatic compression. With increasing fluence both plasma parameters increase and achieve their maxima at a fluence of 12.8 J/cm2 and then decrease. In order to correlate the plasma parameters with surface modification, scanning electron microscope analysis of irradiated Ge was performed. Droplets and cones are formed for both cases. However, the growth of ridges and distinctness of features is more pronounced in case of the absence of the magnetic field; whereas surface structures become more diffusive in the presence of the magnetic field.

Three-Dimensional Discharge Simulation of Inductively Coupled Plasma Etcher

2007 ◽  
Author(s):  
Jia Cheng ◽  
Yu Zhu ◽  
Guanghong Duan ◽  
Yangying Chen
Keyword(s):  
Electron Temperature ◽  
Inductively Coupled Plasma ◽  
Three Dimensional ◽  
Argon Plasma ◽  
Plasma Parameters ◽  
Inductively Coupled ◽  
Parameters Selection ◽  
Dimensional Distribution ◽  
Discharge Model ◽  
Discharge Simulation

Based on the commercial software, CFD-ACE+, a three-dimensional discharge model of an inductively coupled plasma (ICP) etcher was built. The spatial distributions of the electron temperature and the electron number density (END) of the argon plasma were simulated at 10 mTorr, 200 W and 200 sccm. One-dimensional distribution profiles of the plasma parameters above the wafer’s surface at different pressures and powers were compared. These results demonstrate that the END increases with both pressure and power. And the electron temperature decreases with pressure. The methods and conclusions can be used to provide some reference for the configurations of the chamber and the coil of the ICP equipment design and improvement and process parameters selection.

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