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Laser-Induced Breakdown Spectroscopy is a promising spectroscopic technique with a vast spectrum of applications in fields concerned with identification and detection of elements. But it faces some limitations due to self-absorption, noise due to matrix effect and line broadening resulting in low emission signal. This research proposes LIBS signal enhancement by incorporation of metal nanoparticles (Cu, Mg, Au) on Al surface and compares their effect. The successful optical emissions enhancement is achieved as the emission intensities of Al- and Na- lines of three coated samples are compared with those of uncoated Al. The Electron Temperature has been evaluated by Boltzmann plot and an increase in Electron Temperature has been observed with the incorporation of nanoparticles to the aluminum surface as compared to the untreated aluminum, due to more plasma emissions. The Electron Number Density of the aluminum plasma did not have much effect with the incorporation of Nanoparticles. The Local Thermal Equilibrium condition has been satisfied and checked by Mc Whirter's Criterion. The incorporation of metal nanoparticles can be declared as an effective method not only for LIBS signal enhancement but also better detection of trace elements which were not observed without the use of Nanoparticles. [ABSTRACT FROM AUTHOR]

The plasma parameter studies of the Nd:YAG (neodymium-doped yttrium aluminum garnet, Nd:YAlO) crystal by using the fundamental (1064 nm) and second (532 nm) harmonics of Nd:YAG laser are reported. The electron temperature ( T ) and electron number density ( N ) were determined using the Boltzmann plot method and the Stark-broadened line profile, respectively. An increase in the plasma parameters have been observed with an increase in the laser irradiance for both laser modes. The electron temperatures were calculated in the range of 0.53-0.66 eV for 1064 nm and 0.47-0.60 eV for 532 nm, and the electron number densities were determined in the range of 7.43 × 10-3.27 × 10 cm for 1064 nm and 1.35 × 10-3.97 × 10 cm for 532 nm in the studied irradiance range of 1.19-12.5 GW/cm. However, the spatial evolution of the plasma parameters investigated up to 2.75 mm away from the target surface at a fixed laser irradiance of 6.51 GW/cm2 showed a decreasing trend. In addition, the estimated values of the inverse bremsstrahlung (IB) absorption coefficients at both laser wavelengths showed that the IB process is dominant for the 1064-nm laser. [ABSTRACT FROM AUTHOR]

The germanium plasma produced by the fundamental harmonics (1064 nm) of Nd:YAG laser in single and double pulse configurations have been studied spectroscopically. The plasma is characterized by measuring the electron temperature using the Boltzmann plot method for neutral and ionized species and electron number density as a function of laser irradiance, ambient pressure, and distance from the target surface. It is observed that the plasma parameters have an increasing trend with laser irradiance (9-33 GW/cm2) and with ambient pressure (8-250 mbar). However, a decreasing trend is observed along the plume length up to 4.5 mm. The electron temperature and electron number density are also determined using a double pulse configuration, and their behavior at fixed energy ratio and different interpulse delays is discussed. [ABSTRACT FROM AUTHOR]

In the present experimental work, laser induced magnesium plasma has been characterized using plasma parameters. The plasma has been generated by the fundamental (1064 nm) and second harmonics (532nm) of Nd:YAG laser. The plasma parameters such as electron temperature and electron number density have been extracted using Boltzmann plot method and Stark broadened line profile, respectively. The laser irradiance dependence and spatial behavior of electron temperature and number density in laser induced magnesium plasma have been studied. The electron temperature as a function of laser irradiance (0.5 to 6.5GW/cm2) ranges from (9.16-10.37)×10³K and (8.5-10.1) ×10³K, and electron number density from (0.99-1.08)×1016cm-3 and (1.04-1.22)×1016cm-3 for 1064 and 532 nm, respectively. These parameters exhibit fast increase at low laser irradiance and slow increase at high irradiance. The spatial distribution of electron temperature and electron number density shows same decreasing trend up to 2.25mm from the target surface. The electron temperature and number density decrease from (9.5-8.6)×10³K, (1.27-1.15)×1016cm-3 and (10.56-8.85) ×10³K, (1.08-0.99)×1016cm-3 for 532nm and 1064 nm laser ablation wavelengths, respectively. [ABSTRACT FROM AUTHOR]

We report plasma parameters of laser ablated silicon plasma using the fundamental (1064 nm) and second harmonics (532 nm) of a Nd : YAG laser. The electron temperature and electron number density are evaluated using the Boltzmann plot method and Stark broadened line profile, respectively. The electron temperature and electron number density are deduced using the same laser irradiance 2–16 GW cm−2 for 1064 nm and 532 nm as 6350–7000 K and (3.42–4.44) × 1016 cm−3 and 6000–6400 K and (4.20–5.72) × 1016 cm−3, respectively. The spatial distribution of plasma parameters shows a decreasing trend of 8200–6300 K and (4.00–3.60) × 1016 cm−3 for 1064 nm and 6400–5500 K and (5.10–4.50) × 1016 cm−3 for 532 nm laser ablation. Furthermore, plasma parameters are also investigated at low pressure from 45 to 550 mbar, yielding the electron temperature as 4580–5535 K and electron number density as (1.51–2.12) × 1016 cm−3. The trend of the above-mentioned results is in good agreement with previous investigations. However, wavelength-dependent studies and the spatial evolution of plasma parameters have been reported for the first time. [ABSTRACT FROM AUTHOR]