title: Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation.
abstract: We investigate the remote detection of explosives via a technique that vaporizes and photodissociates the condensed-phase material and detects the resulting vibrationally excited NO fragments via laser-induced fluorescence. The technique utilizes a single 7 ns pulse of a tunable laser near 236.2 nm to perform these multiple processes. The resulting blue-shifted fluorescence (226 nm) is detected using a photomultiplier and narrowband filter that strongly block the scatter of the pump laser off the solid media while passing the shorter wavelength photons. Various nitro-bearing compounds, including 2,6-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were detected with a signal-to-noise of 25 dB. The effects of laser fluence, wavelength, and sample morphology were examined.
authors.affiliation: Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, Massachusetts 02420, USA. cwynn@ll.mit.edu
authors.forename: C M
authors.initials: CM
authors.lastname: Wynn
authors.forename: S
authors.initials: S
authors.lastname: Palmacci
authors.forename: R R
authors.initials: RR
authors.lastname: Kunz
authors.forename: K
authors.initials: K
authors.lastname: Clow
authors.forename: M
authors.initials: M
authors.lastname: Rothschild