Journal ArticleDOI
Photodissociation followed by laser-induced fluorescence at atmospheric pressure and 24 degrees C: a unique scheme for remote detection of explosives.
TLDR
A detection sensitivity of at least 8 parts in 10(9) of TNT vapor with a signal-to-noise ratio of approximately 10 has been experimentally verified for an unfocused approximately 5-mJ laser beam, measured at a distance of approximately 15 cm from the TNT sample.Abstract:
A unique scheme has been applied for sensitive remote detection of 2,4,6-trinitrotoluene (TNT) vapor trace amounts at atmospheric pressure and 24 degrees C. The detection concept is based on a single laser beam inducing a tandem process: photodissociation of TNT vapor followed by highly selective detection of its photofragments vibrationally excited NO, utilizing laser-induced fluorescence with the A2Sigma+(v' = 0) <-- X2Pi(v'' = 2) transition. A detection sensitivity of at least 8 parts in 10(9) of TNT vapor with a signal-to-noise ratio of approximately 10 has been experimentally verified for an unfocused approximately 5-mJ laser beam, measured at a distance of approximately 15 cm from the TNT sample.read more
Citations
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Journal ArticleDOI
Standoff detection of high explosive materials at 50 meters in ambient light conditions using a small Raman instrument.
J. Chance Carter,S. Michael Angel,Marion Lawrence-Snyder,Jon Scaffidi,Richard E. Whipple,John G. Reynolds +5 more
TL;DR: Detector gate width studies showed that Raman spectra could be acquired in high levels of ambient light using a 10 microsecond gate width, and Raman signal levels were found to increase linearly with increasing laser energy up to ∼3 × 106 W/cm2 for all samples except TNT.
Journal ArticleDOI
Laser-based standoff detection of explosives: a critical review.
TL;DR: The review includes novel techniques, not yet tested in realistic environments, more mature technologies which have been tested outdoors in realistic environment as well as the most mature millimetre wave imaging technique.
Journal ArticleDOI
Near- and mid-infrared laser monitoring of industrial processes, environment and security applications
TL;DR: In this article, the advantages of infrared laser monitoring in terms of sensitivity, selectivity and the ability of nonintrusive detection of gases are reviewed, where emphasis is laid on direct absorption spectroscopy and evanescent field spectrograms.
Journal ArticleDOI
Luminescence-based methods for sensing and detection of explosives
TL;DR: The detection of explosives and related compounds is important in both forensic and environmental applications and a comprehensive review of these methods is presented.
Journal ArticleDOI
UV gated Raman spectroscopy for standoff detection of explosives
Michael Gaft,Lev Nagli +1 more
TL;DR: In this article, the authors developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 meters.
References
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Journal ArticleDOI
EXPLOSIVES DETECTION: A Challenge for Physical Chemistry
TL;DR: The detection of explosives, energetic materials, and their associated compounds for security screening, demining, detection of unexploded ordnance, and pollution monitoring is an active area of research.
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Interpretation of Raman Spectra of Nitro-Containing Explosive Materials. Part I: Group Frequency and Structural Class Membership
TL;DR: In this article, the Fourier transform (FT)-Raman spectroscopy has been used to obtain high-quality spectra of 32 explosive materials and the majority of the spectra have not previously been reported.
Journal ArticleDOI
Transition probabilities and electronic transition moments of the A 2Σ+–X 2Π and D 2Σ+–X 2Π systems of nitric oxide
Jorge Luque,David R. Crosley +1 more
TL;DR: In this paper, the authors used dispersed fluorescence scans of the A-X(4,v") and D-X (0,v) progressions of nitric oxide, after two-photon excitation, to determine the electronic transition moments of these band systems.
Journal ArticleDOI
Pathways and kinetic energy disposal in the photodissociation of nitrobenzene
TL;DR: In this paper, the authors have observed three primary photodissociation pathways for nitrobenzene at several photolysis wavelengths between 220 and 320 nm, and the relative yield of the pathways producing NO2 and NO varies strongly with the photo-lysis wavelength.
Journal ArticleDOI
2,4,6-Trinitrotoluene detection by laser-photofragmentation–laser-induced fluorescence
TL;DR: Heating of the TNT sample above 343 K was found to increase the magnitude of the PF-LIF signal intensity significantly, but also was finding to cause physical and chemical changes in the TNT samples.