Accession Number:

ADA614507

Title:

Photoacoustic Spectroscopy for Chemical Detection

Descriptive Note:

Journal article

Corporate Author:

ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE

Personal Author(s):

• Holthoff, Ellen L.
• Pellegrino, Paul M.

Report Date:

2012-09-01

Pagination or Media Count:

13.0

Abstract:

The Global War on Terror has made rapid detection and identification of chemical and biological agents a priority for Military and Homeland Defense applications. Reliable real-time detection of these threats is complicated by our enemy s use of a diverse range of materials. Therefore, an adaptable platform is necessary. Photoacoustic spectroscopy PAS is a useful monitoring technique that is well suited for trace detection of gaseous media. This method routinely exhibits detection limits at the parts-per-billion ppb or sub-ppb range. The versatility of PAS also allows for the investigation of solid and liquid analytes. Current research utilizes quantum cascade lasers QCLs in combination with an air-coupled solid-phase photoacoustic cell design for the detection of condensed phase material films deposited on a surface. Furthermore, variation of the QCL pulse repetition rate allows for identification and molecular discrimination of analytes based solely on photoacoustic spectra collected at different film depths.

Descriptors:

• *CHEMICAL DETECTION
• *SPECTROSCOPY
• DEPTH
• LASERS
• THIN FILMS

Subject Categories:

• Unconventional Warfare
• Miscellaneous Detection and Detectors
• Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE