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

Abstract

In this work, the Stark broadening parameters (widths and shifts) of the 2203.5 Á and 4386.5 Á 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 ( 1 O 640 Á), generating pulses of 290 mJ, 7 ns of duration, and a repeat frequency of 20 Hz, has been used far 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 x 10 1 7 to 3 x 10 15 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 far these parameters and also to establish regularities and similarities far said parameters. 3,

Gold Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy and Three-Dimensional Contour Imaging of an Aluminum Alloy

“…The Stark coefficient of Mg(I) at 285.215 nm has been taken from previous studies. 27,28 The laser energies were varied, while the values of the acquisition delay time and the gate width were fixed at 1500 ns and 2000 ns, respectively. The electron density has been calculated from the Hα line at 656.27 nm using LIBS ++ software.…”

“…Since the plasma is in local thermodynamic equilibrium (LTE), the population of the excited states can be described (locally) by the excitation temperature through Boltzmann distribution. The plasma electron density represents a vital parameter to hold the plasma in LTE, its minimum value given by the so-called McWhirter condition 27,28 where N e is the electron density in (cm –3 ), T is the plasma temperature (K), and Δ E (eV) is the energy difference between the upper and lower levels of the transition.…”

Short-Pulse Lasers: A Versatile Tool in Creating Novel Nano-/Micro-Structures and Compositional Analysis for Healthcare and Wellbeing Challenges

“…Indeed, transition probabilities and Stark broadening parameters are missing or given with low accuracy for many atomic and ionic lines. The situation is however progressively improving, as illustrated by the regular updates of the widely used NIST database [203] and the numerous recent reports of new data [204][205][206].…”

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

“…[9][10][11][12][13][14] The Boltzmann plot method has been previously used to estimate the missing values of transition probabilities and Stark broadening parameters of several atomic transitions. 10,[15][16][17][18][19][20][21][22][23][24][25] This should be ultimately carried out provided that at least one of these quantities should be available with sufficient accuracy. 1,5,6,8,10 Several authors calculated the Stark broadening parameters of several transition lines for the copper and some other elements using different techniques.…”