Time-resolved correlated measurement of laser-induced-breakdown spectroscopy and electron number density: application to high-pressure hydrocarbon flames

2017 ◽  
Author(s):  
Anil K. Patnaik ◽  
Paul S. Hsu ◽  
Yue Wu ◽  
Mark Gragston ◽  
Zhili Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Electron Number Density ◽  
Laser Induced Breakdown Spectroscopy ◽  
Number Density ◽  
Electron Number ◽  
Time Resolved ◽  
Hydrocarbon Flames ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

scholarly journals Extracting Time-Resolved Information from Time-Integrated Laser-Induced Breakdown Spectra

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Emanuela Grifoni ◽  
Stefano Legnaioli ◽  
Marco Lezzerini ◽  
Giulia Lorenzetti ◽  
Stefano Pagnotta ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Strong Dependence ◽  
Laser Induced Breakdown Spectroscopy ◽  
Spectral Information ◽  
Acquisition Time ◽  
Number Density ◽  
Plasma Parameters ◽  
Time Resolved ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) data are characterized by a strong dependence on the acquisition time after the onset of the laser plasma. However, time-resolved broadband spectrometers are expensive and often not suitable for being used in portable LIBS instruments. In this paper we will show how the analysis of a series of LIBS spectra, taken at different delays after the laser pulse, allows the recovery of time-resolved spectral information. The comparison of such spectra is presented for the analysis of an aluminium alloy. The plasma parameters (electron temperature and number density) are evaluated, starting from the time-integrated and time-resolved spectra, respectively. The results are compared and discussed.

scholarly journals Spatial confinement effects employed by metallic blocker and Ar gas pressures on laser-induced breakdown spectroscopy and surface modifications of laser-irradiated Mg

2017 ◽  
Vol 35 (2) ◽  
pp. 313-325 ◽  
Author(s):  
A. Hayat ◽  
S. Bashir ◽  
M. S. Rafique ◽  
R. Ahmed ◽  
M. Akram ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Electron Number Density ◽  
Number Density ◽  
Confinement Effects ◽  
Electron Number ◽  
Plasma Parameters ◽  
Spatial Confinement ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Ar Gas

AbstractSpatial confinement effects on plasma parameters and surface morphology of laser-ablated Mg are studied by introducing a metallic blocker as well as argon (Ar) gas at different pressures. Nd: YAG laser at various fluences ranging from 7 to 28 J/cm2 was employed to generate Mg plasma. Confinement effects offered by metallic blocker are investigated by placing the blocker at different distances of 6, 8, and 10 mm from the target surface; whereas spatial confinement offered by environmental gas is explored under four different pressures of 5, 10, 20, and 50 Torr. Laser-induced breakdown spectroscopy analysis revealed that both plasma parameters, that is, excitation temperature and electron number density initially are strongly dependent upon both pressures of environmental gases and distances of blockers. The maximum electron temperature of Mg plasma is achieved at Ar gas pressure of 20 Torr, whereas maximum electron number density is achieved at 50 Torr. It is also observed that spatial confinement offered by metallic blocker is responsible for the significant enhancement of both electron temperature and electron number density of Mg plasma. Maximum values of electron temperature and electron number density without blocker are 8335 K and 2.4 × 1016 cm−3, respectively, whereas these values are enhanced to 12,200 K and 4 × 1016 cm−3 in the presence of blocker. Physical mechanisms responsible for the enhancement of Mg plasma parameters are plasma compression, confinement and pronounced collisional excitations due to reflection of shock waves. Scanning electron microscope analysis was performed to explore the surface morphology of laser-ablated Mg. It reveals the formation of ripples and channels that become more distinct in the presence of blocker due to plasma confinement. The optimum combination of blocker distance, fluence and Ar pressure can identify the suitable conditions for defining the role of plasma parameters for surface structuring.

Determination of Carbon Content in Steel Using Laser-Induced Breakdown Spectroscopy

1992 ◽  
Vol 46 (9) ◽  
pp. 1382-1387 ◽  
Author(s):  
J. A. Aguilera ◽  
C. Aragón ◽  
J. Campos
Keyword(s):  
Carbon Content ◽  
Matrix Effects ◽  
Sample Surface ◽  
Nitrogen Atmosphere ◽  
Laser Induced Breakdown Spectroscopy ◽  
Time Resolved ◽  
Breakdown Spectroscopy ◽  
Use Of Time ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy has been used to determine carbon content in steel. The plasma was formed by focusing a Nd:YAG laser on the sample surface. With the use of time-resolved spectroscopy and generation of the plasma in nitrogen atmosphere, a precision of 1.6% and a detection limit of 65 ppm have been obtained. These values are similar to those of other accurate conventional techniques. Matrix effects for the studied steels are reduced to a small slope difference between the calibration curves for stainless and nonstainless steels.

Time-resolved ultraviolet laser-induced breakdown spectroscopy for organic material analysis

2007 ◽  
Vol 62 (12) ◽  
pp. 1329-1334 ◽  
Author(s):  
Matthieu Baudelet ◽  
Myriam Boueri ◽  
Jin Yu ◽  
Samuel S. Mao ◽  
Vincent Piscitelli ◽  
...  
Keyword(s):  
Organic Material ◽  
Laser Induced Breakdown Spectroscopy ◽  
Time Resolved ◽  
Ultraviolet Laser ◽  
Breakdown Spectroscopy ◽  
Material Analysis ◽  
Laser Induced Breakdown
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