Microscopic simulation of laser induced breakdown threshold in water

2003 ◽  
Author(s):  
Hassan Kaatuzian ◽  
Ahmad Amjadi ◽  
Hossein Mardanpur
2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao

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.


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 ◽  
...  

1998 ◽  
Vol 37 (Part 1, No. 4A) ◽  
pp. 2039-2042 ◽  
Author(s):  
Shin-ya Izumida ◽  
Kin-ya Onishi ◽  
Mitsunori Saito

1968 ◽  
Vol 46 (13) ◽  
pp. 1537-1538 ◽  
Author(s):  
M. Young ◽  
S. L. Chin ◽  
N. R. Isenor

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.


1985 ◽  
Vol 61 ◽  
Author(s):  
M. J. Soileau ◽  
Nastaran Mansour ◽  
Edesly Canto ◽  
D. L. Griscom

ABSTRACTThe effects of radiation damage on bulk laser-induced breakdown in Si02 were studied. Samples studied included Spectrasil A, B, and WF (water free). Measurements of laser-induced breakdown were conducted with 532 and 1064 nm laser pulses of approximately 30 nsec duration. Reductions of up to 50% in the laser-ind ced breakdown threshold were observed at 530 nm for samples exposed to 108 rads of γ-radiation.


1996 ◽  
Vol 50 (12) ◽  
pp. 1483-1499 ◽  
Author(s):  
Rosalie A. Multari ◽  
Leeann E. Foster ◽  
David A. Cremers ◽  
Monty J. Ferris

In laser-induced breakdown spectroscopy (LIBS), a focused laser pulse is used to ablate material from a surface and form a laser plasma that excites the vaporized material. Geometric factors, such as the distance between the sample and the focusing lens and the method of collecting the plasma light, can greatly influence the analytical results. To obtain the best quantitative results, one must consider this geometry. Here we report the results of an investigation of the effect of sampling geometry on LIBS measurements. Diagnostics include time-resolved spectroscopy and temporally and spectrally resolved imaging using an acousto-optic tunable filter (AOTF). Parameters investigated include the type of lens (cylindrical or spherical) used to focus the laser pulse onto the sample, the focal length of the lens (75 or 150 mm), the lens-to-sample distance (LTSD), the angle-of-incidence of the laser pulse onto the sample, and the method used to collect the plasma light (lens or fiber-optic bundle). From these studies, it was found that atomic emission intensities, plasma temperature, and mass of ablated material depend strongly on the LTSD for both types of lenses. For laser pulse energies above the breakdown threshold for air, these quantities exhibit symmetric behavior about an LTSD approximately equal to the back focal length for cylindrical lenses and asymmetric behavior for spherical lenses. For pulse energies below the air breakdown threshold, results obtained for both lenses display symmetric behavior. Detection limits and measurement precision for the elements Be, Cr, Cu, Mn, Pb, and Sr, determined with the use of 14 certified reference soils and stream sediments, were found to be independent of the lens used. Time-resolved images of the laser plasma show that at times >5 μs after plasma formation a cloud of emitting atoms extends significantly beyond the centrally located, visibly white, intense plasma core present at early times (<0.3 μs). It was determined that, by collecting light from the edges of the emitting cloud, one can record spectra using an ungated detector (no time resolution) that resemble closely the spectra obtained from a gated detector providing time-resolved detection. This result has implications in the development of less expensive LIBS detection systems.


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