scholarly journals Influence of the Distance between Focusing Lens and Target Surface on the Characteristics of Laser-excited Lead Plasma

2021 ◽  
pp. 4694-4701
Author(s):  
Qusay Adnan Abbas
Keyword(s):  
Electron Temperature ◽  
Pulse Laser ◽  
Electron Number Density ◽  
Laser Energy ◽  
Pulse Length ◽  
Target Surface ◽  
Spectral Lines ◽  
Stark Broadening ◽  
Number Density ◽  
Electron Number

      The present work investigated the effect of distance from target surface on the parameters of lead plasma excited by 1064nm Q-switched Nd:YAG laser. The excitation was conducted in air, at atmospheric pressure, with pulse length of 5 ns, and at different pulse laser energies. Electron temperature was calculated by Boltzmann plot method based on the PbI emission spectral lines (369.03 nm, 416.98 nm, 523.48, and 561.94 nm). The PbI lines were recorded at different distances from the target surface at laser pulse energies of 260 and 280 mJ. The emission intensity of plasma increased with increasing the lens-to-target distance. The results also detected an increase in electron temperature with increasing the distance between the focal lens and the surface of the target in all laser energies under study. In addition, the electron number density was determined by using the Stark broadening method. The data illustrated that the electron number density was increased with increasing the distance from target surface, reaching the maximum at a distance of 11 cm for all pulse laser energy levels under study.

scholarly journals Measurement of Laser-Induced Plasma: Stark Broadening Parameters of Pb(II) 2203.5 and 4386.5 Å Spectral Lines

2019 ◽  
Vol 73 (2) ◽  
pp. 133-151 ◽  
Author(s):  
Aurelia Alonso-Medina
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Electron Number Density ◽  
Graphical Representation ◽  
Spectral Lines ◽  
Stark Broadening ◽  
Number Density ◽  
Electron Number ◽  
Breakdown Spectroscopy ◽  
Fundamental Wavelength ◽  
And Shifts

In this work, the Stark broadening parameters (widths and shifts) of the 2203.5 Å and 4386.5 Å Pb(II) spectral lines have been investigated and measured in laser-induced breakdown spectroscopy (LIBS), using a lead sample (99.999% purity). A Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser operating at its fundamental wavelength (10 640 Å), generating pulses of 290 mJ, 7 ns of duration, and a repeat frequency of 20 Hz, has been used for the ablation of said lead sample in vacuum and in a controlled argon atmosphere. A study to understand the expansion dynamics of the lead produced plasma was performed. The spectra have been obtained and measured at different time delays of the plasma evolution in the range of 0.15–9 μs, at which the temperature and electron number density are in the ranges of 28 200–8000 K and 1.3 × 1017 to 3 × 1015 cm−3, respectively. A graphical representation of the evolution of temperature and electron number density versus 0.3 to 6.5 μs delay from the laser pulse is presented. The important effect of the different environment where the plasma expands has been pointed out. Local thermodynamic equilibrium conditions have been checked. The obtained results of the Stark widths and shifts at the different temperatures and densities of electrons have been compared with the limited data available in the literature. This study aims to obtain more accurate values for these parameters and also to establish regularities and similarities for said parameters.

Temperature and Electron Number Density of Liquid Jet Double-Pulse Laser Induced Breakdown Ca Plasma

2013 ◽  
Vol 33 (4) ◽  
pp. 0430004
Author(s):  
胡振华 Hu Zhenhua ◽  
张巧 Zhang Qiao ◽  
丁蕾 Ding Lei ◽  
王颖萍 Wang Yingping ◽  
郑海洋 Zheng Haiyang ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Electron Number Density ◽  
Double Pulse ◽  
Liquid Jet ◽  
Number Density ◽  
Electron Number ◽  
Laser Induced Breakdown ◽  
Double Pulse Laser

Electron temperature and electron number density measurements in laser ablation Z-pinch experiments of Al2O3

2019 ◽  
Vol 26 (8) ◽  
pp. 083506
Author(s):  
E. C. Dutra ◽  
J. A. Koch ◽  
R. Presura ◽  
P. Wiewior ◽  
A. M. Covington
Keyword(s):  
Laser Ablation ◽  
Electron Temperature ◽  
Electron Number Density ◽  
Number Density ◽  
Electron Number ◽  
Density Measurements ◽  
Z Pinch

scholarly journals Spectroscopic Characterization of Laser Ablated Germanium Plasma

2021 ◽  
Vol 22 (2) ◽  
pp. 396-403
Author(s):  
Muhammad Ashraf ◽  
Nek Muhammad Shaikh ◽  
Tasneem Zehra ◽  
Ghulam Abbas Kandhro ◽  
Ghulam Murtaza
Keyword(s):  
Electron Temperature ◽  
Electron Number Density ◽  
Plasma Plume ◽  
Research Work ◽  
Spectroscopic Characterization ◽  
Laser Irradiance ◽  
Number Density ◽  
Electron Number ◽  
Boltzmann Plot ◽  
Detector Position

In the present study, the germanium (Ge) sample has been studied by laser induced breakdown spectroscopy which leads to the formation of plasma plume in the air. This research work comprises on pure Ge sample, and it has been studied using laser irradiance 1.831011 watt.cm-2 and Q-Switched Nd:YAG laser pulse (λ ~ 1064 nm wavelength and  ~ 5 ns pulse width). The spatially resolved plasma plume parameters are investigated, such as variation of electron temperature Te and electron number density ne as a function of detector position. These parameters show variation in the plasma plume and yield electron temperature Te from 12340 to 7640 ± 1200 K. Whereas electron number density ne varies from 3.61017 to 1.601017 cm-3 with the change in detector position is moving away from plasma plume from 0 to 3 mm. The results show that electron temperature Te and electron number density ne are estimated from the Boltzmann plot method and by using Lorentzian function at spectral line using FWHM full width at half maximum at 265.11 nm (4p5s 3 p2 → 4p 2 3 p2) wavelength of Ge (I) line, respectively.

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