Deep Ultraviolet Standoff Photoacoustic Spectroscopy of Trace Explosives
Abstract
We demonstrate deep ultraviolet (UV) photoacoustic spectroscopy (PAS) of trace explosives using a sensitive microphone at meter standoff distances. We directly detect 10 µg/cm2 of pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), and ammonium nitrate (AN) with 1 s accumulations from a 3 m standoff distance. Large PAS signals for standoff detection are achieved by exciting into the absorption bands of the explosives with a 213 nm laser. We also investigate the impact of the deep UV photochemistry of AN on the PAS signal strength and stability. We find that production of gaseous species during photolysis of AN enhances the PAS signal strength. This deep UV photochemistry can, however, limit the PAS signal lifetimes when detecting trace quantities.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 10, 2018
- Source ID
- 10.1177/0003702818792289
Entities
People
- Alyssa B Zrimsek
- Sanford A Asher
- Sergei V Bykov
Organizations
- Office of Naval Research
- University of Pittsburgh