Influence of Gas Type on the Laser Produced Graphite Plasma

Plasma graphite creation by a pulsed Nd: YAG laser with a wavelength of 1064nm to a target in vacuum in two cases (Argon, Air) with varied gas pressures and the resulting spectrum was diagnosed using optical emission spectroscopy for the wavelength range 320-740nm electron temperature Te and electron density ne Debye lengthλD , and plasma frequency f p were calculated. The results showed that increasing the pulse laser energy causes all plasma parameters of both gases under study to increase, as well as a rise in the emission line intensity. The ionization energy of target atoms determines the presence of an element’s atomic and ionic emission lines in the emission spectrum, increase in pressure decreases the electron temperature, and Debye length, also plasma frequency and electron density increase, as it has been proven that the type of gas does not affect the properties of plasma.

Spectroscopic analysis of magnesium-aluminum alloys by laser induced breakdown spectroscopy

In this work, the spectra of plasma glow produced by Nd:YAG laser operated at 1.064 μm on Al-Mg alloys with same molar ratio samples in air were analyzed by comparing the atomic lines of aluminum and magnesium with that of strong standard lines. The effect of laser energies on spectral lines, produced by laser ablation, were investigated using optical spectroscopy, the electron density was measured utilizing the Stark broadening of magnesium-aluminum lines and the electron temperature was calculated from the standard Boltzmann plot method. The results that show the electron temperature increases in magnesium and aluminum targets but decreases in magnesium: aluminum alloy target, also show the electron density increase all the aluminum, magnesium and mix both them, It was found that the lines intensities at different laser peak powers increase when the laser peak power increases then decreases when the power continues to increase.

Influence of Water on Spatial Excitation Behavior in the DCP

Spatially resolved excitation temperatures and electron densities in the direct-current plasma (DCP) have been measured as a function of the amount of water introduced to the plasma. Both the excitation temperature and the electron density increase with the quantity of water introduced. The increase in these parameters is large for very low water introduction rates, but slows as the amount of water introduced is increased. A plateau is reached where the amount of water introduced no longer affects the electron concentration or excitation temperature. This plateau is reached at a water introduction rate significantly less than that normally used for routine analytical work.