Time-resolved optical emission spectroscopy of laser-produced air plasma

Abstract

Nonmonotonic radial distribution of excited atoms in a positive column of pulsed direct currect discharges in helium Appl. Phys. Lett. 102, 034104 (2013) Iterative Boltzmann plot method for temperature and pressure determination in a xenon high pressure discharge lamp J. Appl. Phys. 113, 043303 (2013) Surface loss probability of H radicals on silicon thin films in SiH4/H2 plasma J. Appl. Phys. 113, 013303 (2013) A large volume uniform plasma generator for the experiments of electromagnetic wave propagation in plasma Phys. Plasmas 20, 012101 (2013) Diagnosing the plasma nonuniformity in an iron opacity experiment by spatially resolved Al 1s-2p absorption spectroscopy Phys. Plasmas 19, 123301 (2012) Additional information on J. Appl. Phys. The results show a faster decay of continuum and ionic spectral species than of neutral atomic and molecular ones. The velocity and kinetic energy distributions for the different species were obtained from time-of-flight measurements. Excitation temperature and electron density in the laser-induced plasma were estimated from the analysis of spectral data at various times from the laser pulse incidence. Temporal evolution of electron density has been used for the estimation of the three-body recombination rate constant.

Investigation of local thermodynamic equilibrium of laser induced Al2O3–TiC plasma in argon by spatially resolved optical emission spectroscopy

“…By increasing the argon pressure, T ion approaches T exc which means that LTE becomes more valid. Moreover, as it is mentioned by Camacho et al 26 the real plasmas are an approximation to LTE and there is always a spatial inhomogeneity in the means of temperature so LTE is applied only within a small volume of the plasma. To our knowledge, only two works concerning the spatial behavior of the ionic temperature are accomplished.…”

Qualitative Analysis and Plasma Characteristics of Soil from a Desert Area using LIBS Technique

“…The population density of atomic electronic and ionic states could be expressed using the Boltzmann distribution function if the laser induced-plasma fulfills the local thermodynamic equilibrium (LTE) condition. For low-density optically thin plasma, the effects due to re-absorption of plasma emission can be neglected [2]. Consequently, the intensity of the emitted spectral line (I) can be determined from the fractional population of the corresponding energy level of a particular element in the plasma.…”

“…The spectral lines' intensities for particular elements are proportional to the elements' concentration in the sample. In recent years, the growing technique of LIBS has been applied broadly with increasing success in the qualitative and quantitative analyses of soil components and additives with relevant simplification of the conventional methodologies [1][2][3][4]. However, the LIBS technique still needs additional verification before it can be implemented effectively in environmental soil analyses.…”

“…LIBS can analyze any matter regardless of its physical state, be it gas, liquid or solid. LIBS has gained great interest for qualitative and quantitative analysis for many materials including, nano-ceramics, polymers semiconductors etc, because of its ease of use, fast response and high sensitivity [1][2][3][4], Furthermore, remote analysis of the full elemental composition of a sample is achieved via properly optimized LIBS technique [3]. By means of in-situ analysis, both the complexity and the cross contamination of the detection process could be minimized [5].…”

Measurement the Spectroscopic Temperature of Electron in Aluminum Laser Induced Plasma

“…By increasing the fluence over the ablation threshold, the saturation of the produced plasma density allows the increase of the ions and electrons temperatures [7]. Because of the transient features of the plasma created by LIP, optical emission spectroscopy (OES) technique with time and space resolution is especially used to obtain information about the behavior of the created plasma species in space and time as well as the dynamics of the plasma evolution [8][9][10]. The ratio for intensity of two lines of the same species of ionization stage Z in the emission spectrum of the target ablated b laser is expressed as: where I 1 is the line intensity from the k-i transition (arbitrary unit), I 2 is that from the nm transition (arbitrary unit), is the wavelength from the k-i transition (nm), is the wavelength from the n-m transition (nm), is the transition probability from the k-i transition (s -1 ) , is the transition probability from the n-m transition (s -1 ), is the statistical weight of the k state, is the statistical weight of the n state, is the energy of the k state (eV), is the energy of the n state (eV), k B is the Boltzmann constant 1.38x10 -23 J.K -1 , and T e is the electron temperature (eV).…”