Authors: Sausa, Rosario C.; Cabalo, Jerry B.

Source: Applied Spectroscopy, Volume 66, Issue 9, Pages 240A-253A and 987-1090 (September 2012) , pp. 993-998(6)

Publisher: Society for Applied Spectroscopy

Abstract:

Laser-based sensors offer high sensitivity and species selectivity with real-time capabilities for monitoring the vapors of some energetic materials. However, the extremely low vapor pressure of many solid energetic materials under ambient conditions impedes these sensors. In this paper, we report on a novel technique based on laser photoacoustic overtone spectroscopy to detect and differentiate solid 1,3,5-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) in real time at ambient conditions. A tunable, near-infrared laser excites the target compound in the spectral region between 5800 to 6100 cm⁻¹, and a microphone monitors the sound that they generate by non-radiative, collisional de-excitation processes. The photoacoustic signals result from first-overtone and combination absorptions of the energetic material's C-H vibrations, and the collisional processes enhance the signal at atmospheric pressure. The spectra reveal features that are unique to each measured material and these features can serve as a fingerprint for that material. We report the effects of laser energy and wavelength on signal intensity and estimate a detection limit for these compounds.

Keywords: TNT; RDX; CL-20; Overtone spectroscopy; Near-infrared laser radiation; Explosives; Photoacoustic; Detection

Document Type: Research article

DOI: http://dx.doi.org/10.1366/12-06699

Affiliations: 1: U.S. Army Research Laboratory, ARL-RDRL-WML-B, Aberdeen Proving Ground, MD 21005, USA

Publication date: 2012-09-01

More about this publication?

• The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge.
  
  Previously published as Bulletin (Society for Applied Spectroscopy)
• Editorial Board
• Information for Authors
• Submit a Paper
• Subscribe to this Title
• Membership Information
• Request copyrighted SAS materials
• Spectroscopic Nomenclature
• Focus Compendium
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Analytical Chemistry
• By this author: Sausa, Rosario C. ;  Cabalo, Jerry B.

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers