scholarly journals Standoff Detection of Explosives at 1 m using Laser Induced Breakdown Spectroscopy

2017 ◽  
Vol 67 (6) ◽  
pp. 623 ◽  
Author(s):  
Manoj Kumar Gundawar ◽  
Rajendhar Junjuri ◽  
Ashwin Kumar Myakalwar
Keyword(s):  
Electron Density ◽  
Plasma Temperature ◽  
Laser Induced Breakdown Spectroscopy ◽  
Stark Broadening ◽  
Breakdown Spectroscopy ◽  
Standoff Detection ◽  
Laser Induced Breakdown ◽  
Plasma Characteristics ◽  
Detection Of Explosives ◽  
First Time

<p class="p1">We report the ‘standoff detection’ of explosives at 1 m in laboratory conditions, for the first time in India, using Laser Induced Breakdown Spectroscopy combined with multivariate analysis. The spectra of a set of five secondary explosives were recorded at a distance of 1 m from the focusing as well as collection optics. The plasma characteristics viz., plasma temperature and electron density were estimated from Boltzmann statistics and Stark broadening respectively. Plasma temperature was estimated to be of the order of (10.9 ± 2.1) .103 K and electron density of (3.9 ± 0.5) .1016 cm-3. Using a ratiometric approach, C/H and H/O ratios showed a good correlation with the actual stoichiometric ratios and a partial identification success could be achieved. Finally employing principle component analysis, an excellent classification could be attained.<span class="Apple-converted-space"> </span></p>

scholarly journals Plasma Temperature and Electron Density Determination Using Laser-Induced Breakdown Spectroscopy (LIBS) in Earth’s and Mars’s Atmospheres

Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 50
Author(s):  
Julian Stetzler ◽  
Shijun Tang ◽  
Rosemarie C. Chinni
Keyword(s):  
Electron Density ◽  
Plasma Temperature ◽  
The Other ◽  
Laser Induced Breakdown Spectroscopy ◽  
Stark Broadening ◽  
Hydrogen Line ◽  
Electron Densities ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Carbon Peak

The purpose of this study was to calculate and compare the plasma temperatures and electron densities from the laser-induced breakdown spectroscopy (LIBS) data collected by NASA’s Martian rover and compare them to samples measured in Earth’s atmosphere. Using the Boltzmann plots, LIBS plasma temperatures were obtained for each site. The analysis focused on titanium lines that were located in the spectral region between 300 and 310 nm. The electron density was measured using the Stark broadening of the hydrogen line at 656.6 nm; the full width at half maximum (FWHM) of this line can be measured and correlated to the electron density of the plasma. Due to a neighboring carbon peak with the hydrogen line seen in many of the spectra from the Martian sites, the FWHM needed to be calculated using a computer program that completed the other side of the hydrogen line and then it calculated the FWHM for those data samples affected by this. The plasma temperatures and electron densities of the Martian sites were compared to LIBS samples taken on Earth.

Influence of sample temperature on the laser-induced breakdown spectroscopy of a molybdenum–tungsten alloy

2019 ◽  
Vol 34 (12) ◽  
pp. 2378-2384 ◽  
Author(s):  
Ran Hai ◽  
Zhonglin He ◽  
Ding Wu ◽  
Weina Tong ◽  
Harse Sattar ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Electron Density ◽  
Emission Intensity ◽  
Plasma Temperature ◽  
Sample Temperature ◽  
Tungsten Alloy ◽  
Laser Induced Breakdown Spectroscopy ◽  
Spectral Emission ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

During laser ablation, the spectral emission intensity, plasma temperature and electron density increased significantly with increasing sample temperature.

Quantitative Analysis of the Element Silicon by Laser-Induced Breakdown Spectroscopy

2014 ◽  
Vol 1015 ◽  
pp. 27-31
Author(s):  
Xiao Xia Zhao ◽  
Yu Qin Wang ◽  
Wen Feng Luo ◽  
Hai Yan Zhu ◽  
Yuan Yuan Li
Keyword(s):  
Aluminum Alloy ◽  
Limit Of Detection ◽  
Second Harmonic ◽  
Plasma Temperature ◽  
Stark Broadening ◽  
Boltzmann Plot ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Plasma Characteristics ◽  
532 Nm

The second harmonic of a pulsed Nd: YAG laser (532 nm) has been used for the ablation of aluminum alloy in air at atmospheric pressure and the laser-induced plasma characteristics are examined in detail. The electron density of 6.7 × 1017cm-3is inferred from the Stark broadening of the profile of Si (I) 288.16 nm, while the plasma temperature (5982 K) is obtained using the Boltzmann plot method of four neutral aluminum lines. The calibration curve for silicon is established using a set of six samples of standard aluminum alloy, and its limit of detection is 0.0681 wt%. The plasma is verified to be in local thermodynamic equilibrium (LTE) based on the experimental results.

Quantitative Analysis of Aluminum Alloys by Laser-Induced Breakdown Spectroscopy and Plasma Characterization

1995 ◽  
Vol 49 (4) ◽  
pp. 499-507 ◽  
Author(s):  
Mohamad Sabsabi ◽  
Paolo Cielo
Keyword(s):  
Aluminum Alloy ◽  
Quantitative Analysis ◽  
Electron Density ◽  
Atmospheric Pressure ◽  
Laser Induced Breakdown Spectroscopy ◽  
Excitation Temperature ◽  
Stark Broadening ◽  
Pulsed Nd:Yag Laser ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy has been applied to perform elemental analysis of aluminum alloy targets. The plasma is generated by focusing a pulsed Nd:YAG laser on the target in air at atmospheric pressure. Such a plasma was characterized in terms of its appearance, emission spectrum, space-integrated excitation temperature, and electron density. The electron density is inferred from the Stark broadening of the profiles of ionized aluminum lines. The temperature is obtained by using Boltzmann plots of the neutral iron lines. Calibration curves for magnesium, manganese, copper, and silicon were produced. The detection limits are element-dependent but are on the order of 10 ppm.

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