Correction of self-absorption effect in calibration-free laser-induced breakdown spectroscopy(CF-LIBS) by considering plasma temperature and electron density

Optik ◽  
2020 ◽  
Vol 208 ◽  
pp. 163702
Author(s):  
Yanwei Yang ◽  
Xiaojian Hao ◽  
Long Ren
2015 ◽  
Vol 30 (6) ◽  
pp. 1336-1344 ◽  
Author(s):  
Juan Dong ◽  
Long Liang ◽  
Jiao Wei ◽  
Hongsheng Tang ◽  
Tianlong Zhang ◽  
...  

An internal reference-external standard with iteration correction (IRESIC) method is proposed to correct for the self-absorption effect and plasma temperature in CF-LIBS based on an internal reference line and one standard sample.


2019 ◽  
Vol 34 (12) ◽  
pp. 2378-2384 ◽  
Author(s):  
Ran Hai ◽  
Zhonglin He ◽  
Ding Wu ◽  
Weina Tong ◽  
Harse Sattar ◽  
...  

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


2018 ◽  
Vol 3 (8) ◽  
pp. 50 ◽  
Author(s):  
Tagreed K. Hamad ◽  
Hussein Thamer Salloom

In this study, Calibration-free Laser-induced breakdown spectroscopy (CF-LIBS) was applied to quantitatively analyze the elemental composition of Ti-6Al-4V titanium based alloy samples with no need for matrix-matched calibration procedure. Nd:YAG pulsed laser operating at a wavelength of 1064 nm was focused onto the sample to generate plasma. The spectrum of plasma was recorded using spectrophotometer then compared to NIST spectral lines to determine characteristic wavelengths, energy levels and other spectroscopic parameters. The values of plasma temperature obtained using Boltzmann plot for four examined samples ranged from 7439 to 6826 K while the electron density for each element was determined using Boltzmann-Saha equation. The concentration of Ti, Al, V and Fe has been determined and were within the samples nominal concentrations obtained from XRF analysis.  The calculated average relative errors of Ti, Al, V and Fe were 0.39%, 4.38%, 4.94 % and 8.2 %, respectively. Finally, there was a direct proportionality relation between the ratio of ionic to neutral emission lines of Ti for four samples and the surface hardness values measured mechanically using Vickers hardness test. The ratio at   had the best linear regression value (R2=0.95) which indicates the best correlation with surface hardness.


Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 50
Author(s):  
Julian Stetzler ◽  
Shijun Tang ◽  
Rosemarie C. Chinni

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.


2017 ◽  
Vol 67 (6) ◽  
pp. 623 ◽  
Author(s):  
Manoj Kumar Gundawar ◽  
Rajendhar Junjuri ◽  
Ashwin Kumar Myakalwar

<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>


Sign in / Sign up

Export Citation Format

Share Document