Radial variation of laser--induced air plasma parameters

2006 ◽  
Author(s):  
M. Mathuthu ◽  
R. Raseleka ◽  
A. Forbes
Keyword(s):  
Radial Variation ◽  
Air Plasma ◽  
Plasma Parameters

Air Plasma Parameters in Normal and Seismic Conditions

2018 ◽  
Vol 12 (1) ◽  
pp. 179-184 ◽  
Author(s):  
N. V. Ardelyan ◽  
V. L. Bychkov ◽  
G. V. Golubkov ◽  
K. V. Kosmachevskii
Keyword(s):  
Air Plasma ◽  
Plasma Parameters

Air Plasma Parameters of the Lower Ionosphere under Normal Conditions

2018 ◽  
Vol 12 (4) ◽  
pp. 755-759
Author(s):  
G. V. Golubkov ◽  
N. V. Ardelyan ◽  
V. L. Bychkov ◽  
K. V. Kosmachevskii
Keyword(s):  
Lower Ionosphere ◽  
Air Plasma ◽  
Plasma Parameters

scholarly journals Radial Variation of Refractive Index, Plasma Frequency and Phase Velocity in Laser Induced Air Plasma

2006 ◽  
Vol 34 (6) ◽  
pp. 2554-2560 ◽  
Author(s):  
Manny Mathuthu ◽  
Rita M. Raseleka ◽  
Andrew Forbes ◽  
Nicholas West
Keyword(s):  
Refractive Index ◽  
Phase Velocity ◽  
Plasma Frequency ◽  
Radial Variation ◽  
Air Plasma

Laser Ablation of Ti-Al Alloy in Vacuum and Air Environments

2012 ◽  
Vol 217-219 ◽  
pp. 2257-2264 ◽  
Author(s):  
Yue Hua Liu ◽  
Xiang Dong Liu ◽  
Ming Chen ◽  
Ming Wen Zhao
Keyword(s):  
High Power ◽  
Laser Energy ◽  
Optical Emission ◽  
Target Surface ◽  
Al Alloy ◽  
Laser Irradiance ◽  
Air Plasma ◽  
High Power Laser ◽  
Power Laser ◽  
Plasma Parameters

The time-resolved optical emission spectroscopy of Ti-Al alloy plasma produced by the Nd:YAG high-power laser pulses with wavelength of 1064nm was investigated both in air and vacuum conditions. The comparative studies gave detailed insights that the plasmas produced in air were much hotter and denser. The quantitative descriptions indeed suggested that a cascade avalanche process would be happen followed by air plasma firstly, before the laser impacting the target surface. On the other hand, the laser energy may be considerably attenuated via hotter and denser plasma, the amount of laser energy on the target surface remarkably decreased in air condition. In addition, at high-power laser irradiance levels, there was an auto regulatory area near the target surface and the plasma parameters tend to be saturated

scholarly journals Experimental study for the properties of Fe3O4 dusty plasma using the air in vacuum chamber system

2019 ◽  
Vol 13 (26) ◽  
pp. 151-159
Author(s):  
Ala’ Fadhil Ahmed
Keyword(s):  
Experimental Study ◽  
Discharge Current ◽  
Current System ◽  
Debye Length ◽  
Dust Particles ◽  
Floating Potential ◽  
Saturation Current ◽  
Air Plasma ◽  
Plasma Region ◽  
Plasma Parameters

In this work, we carried out an experimental study of thedustyplasma by taking the dust material Fe3O4 with radius of the any grain0.1μm - 0.5μm. In experiment we use air in the vacuum chambersystem under different low pressure (0.1-1) Torr. The resultsillustrated that the present of dust particles in the air plasma did noteffect on Paschen minimum which is 0.5 without dust and with Fe3O4dusty grains.The effect of Fe3O4 dust particles on plasma parameters can benotice in direct current system in glow discharge region. The plasmaparameters which were studied in this work represent plasmapotential, floating potential,electron saturation current, temperatureof the electron, the density of the (electron, ion), and Debye length.The measurements of parameters are taken by four cylindrical probeswhich diagnosed at distance 4cm from the diameter of the cathode inPaschen minimum at pressure 0.5 Torr. The diameter profiles ofplasma parameters in the present of dust are non- uniform. Plasmapotential and the floating potential of probe becomes more negativelywhen the dust immersed into plasma region. The electron densityincreases in the present of dust particle which lead to decrease theelectron temperature and Debye length. The behavior of thoseparameters shows the discharge current and discharge voltageincreases without dust while the discharge current and voltagedecreases when Fe3O4 dust particles embedded.

EXPRESS: Feasibility of Using Boltzmann Plots to Evaluate the Stark Broadening Parameters of Cu(I) Lines

2021 ◽  
pp. 000370282110133
Author(s):  
Mohamed Fikry ◽  
Ibraheem A. Alhijry ◽  
A. M. Aboulfotouh ◽  
Ashraf M. EL Sherbini
Keyword(s):  
Electron Density ◽  
Missing Values ◽  
Pure Copper ◽  
Spectral Lines ◽  
Stark Broadening ◽  
Air Plasma ◽  
Plasma Parameters ◽  
Boltzmann Plot ◽  
Copper Target ◽  
Delay Times

A linear Boltzmann plot was constructed using Cu I-lines of well-known atomic parameters. Aligning other spectral lines to the plot was adopted as a viable way to estimate the most probable values of Stark broadening parameters of Cu I-lines at 330.79, 359.91, and 360.2 nm. Plasma was generated by focusing of Nd: YAG laser radiation at wavelength 532 nm on a pure copper target in open air. Plasma emission was recorded at delay times of 3, 4, 5, 7, and 10 μs. The in situ optically thin H<sub>α</sub>-line was used to determine the plasma reference electron density over the entire experiment. Following this method, the missing values of the Stark broadening parameters of the three Cu-I lines turn out to be about 0.15 ± 0.05 Å (for 330.79 nm transition) and 0.17 ± 0.05 Å (for 359.91, and 360.20 nm transition) at reference electron density of (1 ± 0.09)×10<sup>17</sup> cm<sup>-3</sup> and temperature of 10800 ± 630 K. The apparent variation in plasma parameters at different delay times was found to scale with electron density and temperature as <i>~ n<sub>e</sub>.T<sub>e</sub><sup>0.166</sup></i>.

HOT CORROSION OF CERIA-YTTRIA STABILIZED ZIRCONIA PLASMA SPRAYED THERMAL BARRIER COATING BY EUTECTIC VANDIUM PENTAOXIDE-SODIUM SULFATE

2018 ◽  
Vol 18 (1) ◽  
pp. 182-192 ◽  
Author(s):  
Mohammed J Kadhim ◽  
Mohammed H Hafiz ◽  
Maryam A Ali Bash
Keyword(s):  
Thermal Barrier Coating ◽  
Hot Corrosion ◽  
Monoclinic Phase ◽  
Volume Fraction ◽  
High Volume ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Plan View ◽  
Barrier Coating ◽  
Plasma Sprayed

The high temperature corrosion behavior of thermal barrier coating (TBC) systemconsisting of IN-738 LC superalloy substrate, air plasma sprayed Ni24.5Cr6Al0.4Y (wt%)bond coat and air plasma sprayed ZrO2-20 wt% ceria-3.6 wt% yttria (CYSZ) ceramic coatwere characterized. The upper surfaces of CYSZ covered with 30 mg/cm2 , mixed 45 wt%Na2SO4-55 wt% V2O5 salt were exposed at different temperatures from 800 to 1000 oC andinteraction times from 1 up to 8 h. The upper surface plan view of the coatings wereidentified for topography, roughness, chemical composition, phases and reaction productsusing scanning electron microscopy, energy dispersive spectroscopy, talysurf, and X-raydiffraction. XRD analyses of the plasma sprayed coatings after hot corrosion confirmed thephase transformation of nontransformable tetragonal (t') into monoclinic phase, presence ofYVO4 and CeVO4 products. Analysis of the hot corrosion CYSZ coating confirmed theformation of high volume fraction of YVO4, with low volume fractions of CeOV4 and CeO2.The formation of these compounds were combined with formation of monoclinic phase (m)from transformation of nontransformable tetragonal phase (t').

Sign in / Sign up

Export Citation Format

Share Document