Preferred Language
Articles
/
joe-2196
Modeling of Electron and Lattice Temperature Distribution Through Lifetime of Plasma Plume
...Show More Authors

When employing shorter (sub picosecond) laser pulses, in ablation kinetics the features appear which can no longer be described in the context of the conventional thermal model. Meanwhile, the ablation of materials with the aid of ultra-short (sub picosecond) laser pulses is applied for micromechanical processing. Physical mechanisms and theoretical models of laser ablation are discussed. Typical associated phenomena are qualitatively regarded and methods for studying them quantitatively are considered. Calculated results relevant to ablation kinetics for a number of substances are presented and compared with experimental data. Ultra-short laser ablation with two-temperature model was quantitatively investigated. A two-temperature model for the description of transition phenomena in a non-equilibrium electron gas and a lattice under picosecond laser irradiation is proposed. Some characteristics are hard to measure directly at all. That is why the analysis of physical mechanisms involved in the ablation process by ultra-short laser pulses has to be performed on the basis of a theoretical consideration of `indirect' experimental data. For Copper and Nickel metal targets, the two-temperature model calculations explain that the temperature of the electron subsystem increased suddenly and approached a peak value at the end of laser pulse. In addition, the temperature profile of lattice temperature subsystem evolution slowly, and still increasing after the end of laser pulse. A good agreement prevails when a comparison between the present results and published results.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Estimation of electron temperature for SiO2 plasma induced by laser
...Show More Authors

In this work; Silicon dioxide (SiO2) were fabricated by pulsed
laser ablation (PLA). The electron temperature was calculated by
reading the data of I-V curve of Langmuir probe which was
employed as a diagnostic technique for measuring plasma properties.
Pulsed Nd:YA Glaser was used for measuring the electron
temperature of SiO2 plasma plume under vacuum environment with
varying both pressure and axial distance from the target surface. The
electron temperature has been measured experimentally and the
effects of each of pressure and Langmuir probe distance from the
target were studied. An inverse relationship between electron
temperature and both pressure and axial distance was observed.

View Publication Preview PDF
Crossref
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Effect of gas flow rate on plasma temperature and electron density of atmospheric argon plasma jet
...Show More Authors

In this study, method for experimentally determining the electron density (ne) and the electron temperature (Te) in the atmospheric Argon plasma jet is used; it is based on optical emission spectroscopy (OES). Boltzmann plot method used to calculate these parameters measured for different values of gas flow rate. The results show that the electron temperature decreasing with the increase of gas flow rate also indicates an increasing in the electron density of plasma jet with increasing of gas flow rate.

View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Baghdad Science Journal
Enhancement of Electron Temperature under Dense Homogenous Plasma by Pulsed Laser Beam
...Show More Authors

The applications of hot plasma are many and numerous applications require high values of the temperature of the electrons within the plasma region. Improving electron temperature values is one of the important processes for using this specification in plasma for being adopted in several modern applications such as nuclear fusion, plating operations and in industrial applications. In this work, theoretical computations were performed to enhance electron temperature under dense homogeneous plasma. The effect of   power and duration time of pulsed Nd:YAG laser   was studied on the heating of   plasmas  by inverse bremsstrahlung  for  several values for the electron density ratio. There results for these ca

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Spectroscopic measurements of the electron temperature in low pressure microwave 2.45 GHz argon plasma
...Show More Authors

The main goal of this work is to obtain the plasma electron temperature Te by optical emission spectroscopy of low pressure microwave argon plasma, as a function of working pressure and microwave power. A plasma system was designed and constructed in our laboratory using a magnetron of domestic microwave oven with power 800W without any commercial part. The applied voltage on the magnetron electrical circuit is changed for the purpose of obtaining the variable values of the microwave power. The spectral detection is performed with a spectrometer of wavelength range (200−1000nm). The working pressure and magnetron applied voltage were 0.3-3.0mbar and 180-240V, respectively. Two methods had been applied to estimate the electron temperatu

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Sep 11 2019
Journal Name
Aip Conference Proceedings
Estimation of shock wave position in plasma plume using Sedov-Taylor model
...Show More Authors

In this work, radius of shock wave of plasma plume (R) and speed of plasma (U) have been calculated theoretically using Matlab program.

Publication Date
Sun Dec 01 2002
Journal Name
Iraqi Journal Of Physics
Photophysics of Coumarin 460: Temperature Effect upon Fluorescence Lifetime and Non-Radiative Rate Parameter
...Show More Authors

The temperature influence on the fluorescence lifetime, quantum yields and non-radiative rate parameter or coumarin 460 dye dissolved in methanol was investigated in the temperature range (160-300 k). A single photon counting technique was used or measuring the fluorescence decay curves. A noticeable decrease of the fluorescence lifetime with increasing the temperature was observed. The non-radiative activation energy of 10.57 K.J. mole-1 was measured by the help of Arrhenius plot.

View Publication Preview PDF
Publication Date
Wed Mar 01 2023
Journal Name
Iraqi Journal Of Physics
Theoretical Computation of Electron Density in Laser-Induced Carbon Plasma using Anisimov Model
...Show More Authors

In this work, electron number density calculated using Matlab program code with the writing algorithm of the program. Electron density was calculated using Anisimov model in a vacuum environment. The effect of spatial coordinates on the electron density was investigated in this study. It was found that the Z axis distance direction affects the electron number density (ne). There are many processes such as excitation; ionization and recombination within the plasma that possible affect the density of electrons. The results show that as Z axis distance increases electron number density decreases because of the recombination of electrons and ions at large distances from the target and the loss of thermal energy of the electrons in

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
Electron Contribution to Stopping Power in Burning Plasma
...Show More Authors

The dependence of the energy losses or the stopping power for the energies and the related penetrating factor are arrive by using a theoretical approximation models. in this work we reach a compatible agreement between our results and the corresponding experimental results.

View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Fri Oct 01 2021
Journal Name
Physica E: Low-dimensional Systems And Nanostructures
In-situ lattice structure analysis in sp2 hybridization of stable carbon isotopes: Precision modelling of temperature
...Show More Authors

View Publication
Scopus Clarivate Crossref
Publication Date
Wed Aug 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Influence of Simultaneous Doping of Tl on the Transition Temperature Tc and the Lattice Parameters of HgBa2Ca2Cu3O8+ δ Superconductors
...Show More Authors

        In the present study, we have reported investigations on the effect of simultaneous substitution of Tl at the Hg site in the oxygen deficient HgOδ layer of Hg1-xTlxBa2Ca2Cu3O8+ δ cuprate superconductor. Bulk polycrystalline samples were prepared by the two-step solid state reaction process. It was observed that the grown Hg1-xTlxBa2Ca2Cu3O8+ δ corresponds to the 1223 phase. Electrical resistivity, using four probe technique, is used to find the transition temperature Tc. The highest Tc(0ffset) were 108, 102,113, 118, 125 and 121K for Hg1xTlxBa2Ca2Cu3O8+ δ with x = 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25 respectively. The optimum Tc(off) of ~ 125 K and Tc(onset) ~ 136K   was fo

... Show More
View Publication Preview PDF