scholarly journals Magnetic field effect on laser-induced breakdown spectroscopy and surface modifications of germanium at various fluences

2017 ◽  
Vol 35 (1) ◽  
pp. 159-169 ◽  
Author(s):  
H. Iftikhar ◽  
S. Bashir ◽  
A. Dawood ◽  
M. Akram ◽  
A. Hayat ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Temperature ◽  
Surface Modifications ◽  
Laser Induced Breakdown Spectroscopy ◽  
Excitation Temperature ◽  
Number Density ◽  
Plasma Parameters ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
The Magnetic Field

AbstractThe effect of the transverse magnetic field on laser-induced breakdown spectroscopy and surface modifications of germanium (Ge) has been investigated at various fluences. Ge targets were exposed to Nd: YAG laser pulses (1064 nm, 10 ns, 1 Hz) at different fluences ranging from 3 to 25.6 J/cm2 to generate Ge plasma under argon environment at a pressure of 50 Torr. The magnetic field of strength 0.45 Tesla perpendicular to the direction of plasma expansion was employed by using two permanent magnets. The emission spectra of laser-induced Ge plasma was detected by the laser-induced breakdown spectroscopy system. The electron temperature and number density of Ge plasma are evaluated by using the Boltzmann plot and stark broadening methods, respectively. The variations in emission intensity, electron temperature (Te), and number density (ne) of Germanium plasma are explored at various fluences, with and without employment of the magnetic field. It is observed that the magnetic field is responsible for significant enhancement of both excitation temperature and number density at all fluences. It is revealed that an excitation temperature increases from Te,max,without B = 16,190 to Te,max,with B = 20,123 K. Similarly, the two times enhancement in the electron density is observed from ne,max,without B = 2 × 1018 to ne,max,with B = 4 × 1018 cm−3. The overall enhancement in Ge plasma parameters in the presence of the magnetic field is attributed to the Joule heating effect and adiabatic compression. With increasing fluence both plasma parameters increase and achieve their maxima at a fluence of 12.8 J/cm2 and then decrease. In order to correlate the plasma parameters with surface modification, scanning electron microscope analysis of irradiated Ge was performed. Droplets and cones are formed for both cases. However, the growth of ridges and distinctness of features is more pronounced in case of the absence of the magnetic field; whereas surface structures become more diffusive in the presence of the magnetic field.

Measurement of Plasma Parameters of Fe-Lines in Lipstick Using Laser-Induced Breakdown Spectroscopy

2021 ◽  
Vol 19 (10) ◽  
pp. 01-07
Author(s):  
M.H. Asmaa ◽  
Sami A. Habana
Keyword(s):  
Electron Temperature ◽  
Debye Length ◽  
Nuclear Data ◽  
Laser Induced Breakdown Spectroscopy ◽  
Current Investigation ◽  
Plasma Parameters ◽  
Data Set ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Business Sectors

Electron thickness and temperature of laser prompted Iron plasma boundaries, among different boundaries, were estimated. Plasma was delivered through the connection of high pinnacle power Nd: YAG laser at the key frequency of 1064 nm with a pellet target contains a limited quantity of lipstick from nearby business sectors. Lines from Fe II at 238.502 nm, Fe II at 254.904 nm, Fe II at 262.370 nm, Fe II at 286.545 nm and Fe I at 349.779 nm were utilized to assess the plasma boundaries. The current investigation was completed to assess electron temperature (Te), electron thickness (ne), plasma recurrence, Debye length and Debye number (ND). Laser-incited breakdown spectroscopy LIBS method was used for examining and deciding ghastly discharge lines. ID of change lines from all spectra was completed by contrasting ghostly lines and NIST nuclear data set.

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.

scholarly journals Enhancement of Laser-induced Breakdown Spectroscopy (LIBS) Signal Subject to the Magnetic Confinement and Dual Pulses-=SUP=-*-=/SUP=-

2021 ◽  
Vol 129 (4) ◽  
pp. 538
Author(s):  
Atif Hussain ◽  
Gao Xun ◽  
Haroon Asghar ◽  
Muhammad Azam ◽  
Qura-tul-Ain -=SUP=-1-=/SUP=- ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Optical Emission ◽  
Magnetic Confinement ◽  
Signal Enhancement ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Plasma Parameters ◽  
Maximum Enhancement ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In this work, a comparative study for the laser-induced breakdown spectroscopy (LIBS) of aluminium (Al) target has been performed by using the two kinds of enhancement techniques namely, magnetic confinement and double pulse-LIBS (DP-LIBS). Firstly, the signal enhancement of Al plasma by combining the LIBS with an external magnetic field was exposed. Secondly, the signal enhancement by configuring the dual-pulses action in LIBS was performed. We found that the optical emission lines and plasma parameters (electron temperature and density) showed significant enhancement in the presence of magnetic field and DP-LIBS. During the magnetic confinement, the maximum enhancement factors of about 6 and 8 were achieved for the spectral line Mg (II) 279.5 nm and Al (II) 280.1 nm, respectively. An enhancement factor was reached up to 12-folds for the various spectral lines in DP-LIBS. Our results have significance in improving the LIBS sensitivity. Keywords: LIBS, spectral lines, magnetic confinement, Boltzmann, dual pulses

scholarly journals Influence of Lead on the Interpretation of Bone Samples with Laser-Induced Breakdown Spectroscopy

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Abdolhamed Shahedi ◽  
Esmaeil Eslami ◽  
Mohammad Reza Nourani
Keyword(s):  
Plasma Temperature ◽  
Laser Induced Breakdown Spectroscopy ◽  
Plasma Parameters ◽  
Time Duration ◽  
Laboratory Rats ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Group A ◽  
Atomic Lines ◽  
Group B

This study is devoted to tracing and identifying the elements available in bone sample using Laser-Induced Breakdown Spectroscopy (LIBS). The bone samples were prepared from the thigh of laboratory rats, which consumed 325.29 g/mol lead acetate having 4 mM concentration in specified time duration. About 76 atomic lines have been analyzed and we found that the dominant elements are Ca I, Ca II, Mg I, Mg II, Fe I, and Fe II. Temperature curve and bar graph were drawn to compare bone elements of group B which consumed lead with normal group, group A, in the same laboratory conditions. Plasma parameters including plasma temperature and electron density were determined by considering Local Thermodynamic Equilibrium (LTE) condition in the plasma. An inverse relationship has been detected between lead absorption and elements like Calcium and Magnesium absorption comparing elemental values for both the groups.

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