Spectroscopic characterization of laser-induced tin plasma

Abstract

Optical emission spectroscopic studies have been carried out on a tin plasma generated using 1064-nm, 8-ns pulses from a Nd:yttrium aluminum garnet laser. Temperature and density were estimated from the analysis of spectral data. The temperature measurements have been performed by Boltzmann diagram method using singly ionized Sn lines, while density measurements were made using the Stark broadening method. An initial temperature of 3.2 eV and density of 7.7×1017cm−3 were measured. Temporal and spatial behaviors of electron temperature and density in the laser-generated tin plasma have been analyzed. Time evolutions of density and temperature are found to decay adiabatically at early times. The spatial variation of density shows approximately 1∕z dependence. The time-integrated temperature exhibits an appreciable rise at distances greater than 7 mm. This may be caused by the deviation from local thermodynamic equilibrium at larger distances from the target surface.

Influence of spot size on propagation dynamics of laser-produced tin plasma

“…Plume images recorded with an ICCD camera are spectrally integrated in the wavelength region 350-900 nm and in this spectral window, most of the emission from the Sn plasma is due to excited neutral and singly ionized tin. 34,35 But, it should be remembered that tin plasma contains highly charged Sn species and they are not emitting in the visible region. For example, the UTA emission around 13.5 nm is mainly contributed by Sn 8+ to Sn 13+ ions.…”

Radial Variation of Refractive Index, Plasma Frequency and Phase Velocity in Laser Induced Air Plasma

“…The LIBS technique has found vast applications as a diagnostic tool in elemental composition analysis for trace pollutants in soil [9], in water [10], and for studying particle velocity, electron temperature, and density in air plasmas [6], [11]. This versatility enables the LIBS technique to compete with other diagnostic techniques such as: XRF, AAS, ICP-OES, interferometry, and beam deflectometry [5]. In LIBS, the quantitative infomation can be obtained on the entire sample composition in a single run.…”

“…Also, to our knowledge, there is not enough research on the radial profiles of electron temperature, density, plasma frequency, refractive index, and phase velocity. However, axial profiles of some of these parameters have received considerable attention [1], [5] and for air, an attempt has been made to study the shock and thermal waves using beam deflection techniques [15]. Here, the plasma was shown to suffer changes in refractive index by deflecting a He-Ne beam passing through it.…”

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

“…The peak velocities of N + and O + increase with the distance from the target surface. This trend has been reported previously, 34 and is due to the initial acceleration of the ablated particles from zero velocity to a maximum velocity.…”