Measurement of laser-induced breakdown threshold intensities of high-pressure gasses and water droplets to determine the number density of an aerosol

2011 ◽  
Vol 284 (12) ◽  
pp. 3004-3007 ◽  
Author(s):  
H. Yashiro ◽  
F. Sasaki ◽  
H. Furutani
Keyword(s):  
High Pressure ◽  
Number Density ◽  
Water Droplets ◽  
Breakdown Threshold ◽  
Laser Induced Breakdown

Laser-induced breakdown in freon-doped rare gas

1968 ◽  
Vol 46 (13) ◽  
pp. 1537-1538 ◽  
Author(s):  
M. Young ◽  
S. L. Chin ◽  
N. R. Isenor
Keyword(s):  
High Pressure ◽  
Multiphoton Ionization ◽  
Low Pressure ◽  
Rare Gas ◽  
Breakdown Threshold ◽  
Argon Gas ◽  
Cascade Theory ◽  
Laser Induced Breakdown

The breakdown of argon gas containing freon-12 impurity is reported. At high pressure the freon increases the breakdown threshold, while at low pressure it decreases the threshold. This behavior is shown to result from attachment and multiphoton ionization of the freon. The experiment is considered to provide further evidence for multiphoton ionization and for the cascade theory of breakdown.

Measurement of Number Density of Water Droplets in Aerosol by Laser-Induced Breakdown

2010 ◽  
Vol 3 (3) ◽  
pp. 036601 ◽  
Author(s):  
Hidehiko Yashiro ◽  
Fumio Sasaki ◽  
Masayuki Kakehata
Keyword(s):  
Number Density ◽  
Water Droplets ◽  
Laser Induced Breakdown ◽  
Density Of Water

Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao
Keyword(s):  
Femtosecond Laser ◽  
Spatial Resolution ◽  
Laser Induced Breakdown Spectroscopy ◽  
Nanosecond Laser ◽  
Breakdown Threshold ◽  
Powerful Technique ◽  
Breakdown Spectroscopy ◽  
Continuous Radiation ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.

Temporally and spatially resolved measurements of the number density of water droplets in an intermittent aerosol

2010 ◽  
Vol 49 (17) ◽  
pp. 3305 ◽  
Author(s):  
Hidehiko Yashiro ◽  
Masayuki Kakehata ◽  
Fumio Sasaki
Keyword(s):  
Number Density ◽  
Water Droplets ◽  
Spatially Resolved ◽  
Density Of Water

Laser-induced breakdown threshold and fracture versus the nanostructure of two-phase glass

2006 ◽  
Vol 51 (7) ◽  
pp. 872-877 ◽  
Author(s):  
N. F. Morozov ◽  
Yu. K. Startsev ◽  
Yu. V. Sud’enkov ◽  
A. A. Suslikov ◽  
G. A. Baranov ◽  
...  
Keyword(s):  
Breakdown Threshold ◽  
Two Phase ◽  
Laser Induced Breakdown ◽  
Phase Glass

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.

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