Standoff Raman Detection of Explosive Materials Using a Small Raman Spectroscopy System

Abstract

In this work a standoff Raman spectroscopy SRS system has been designed, assembled and tested for detecting explosives (Ammonium nitrate, Trinitrotoluene and Urea nitrate) in dark laboratory at 4 m target-telescope distance. The SRS system employs frequency doubled Nd:YAG laser at 532 nm excitation with laser power of 250 mW and integration time of 2 second. The Cassegrain telescope was coupled to the Ventana Raman spectrometer using a fiber optics cable, and Notch filter is used to reject Rayleigh scattering light. The Raman scattered light is collected by a telescope and then transferred via fiber optic to spectrometer and finally directed into charge coupled device CCD detector. In order to test SRS system, it has been used to detect the Raman spectra of Toxic Industrial Compounds TIC such as acetone, toluene, and carbon tetrachloride. The SRS results were compared with conventional Raman microscopy results using a bench top Bruker SENTERRA Raman instrument.

Laser Photochemical Nanostructuring of Silicon for Surface Enhanced Raman Spectroscopy

“…The observed Raman bands in Figure 8a,c are partially common with BCB spectra shown in above figures, for the wavenumbers around 1200, 1400, and 1600 cm −1 whereas in NH 4 NO 3 characteristic peak is found at 1045 cm −1 denoting the N−O symmetric stretching. [ 37 ]…”

“…The observed Raman bands in Figure 8a,c are partially common with BCB spectra shown in above figures, for the wavenumbers around 1200, 1400, and 1600 cm −1 whereas in NH 4 NO 3 characteristic peak is found at 1045 cm −1 denoting the N−O symmetric stretching. [37] Table 2. Normalized intensity values obtained from both dark field scattering spectra and simple FDTD simulation model scattering cross-section of 50 nm deposited Ag and Au substrates.…”

Stand-off detection of explosive hazards based on time-gated Raman spectroscopy

“…In an international perspective, there are currently lots of research activities concerning explosive hazards detection, and stand-off detection of explosives is in main focus [1,2]. The reason for this interest is the occurrence of terrorist attacks on the civilian society involving improvised explosives devices IED [3][4][5]. Laser-based spectroscopies are the only currently viable techniques that can be utilized to sense trace amounts of explosives at stand-off distances.…”

Thermal decomposition of ammonium nitrate (AN) in the presence of the optimized nano-ternary transition metal ferrite CoNiZnFe2O4

“…[13][14][15] The additives such as metals, metal oxides, organic-inorganic oxides, ferrites, and bimetal oxides have been reported to enhance the thermal decomposition of AN. [16][17][18] Moreover, the ability of metal oxides/ferrites to serve as a bridge in the electron or proton transfer process from the decomposed products of the AN molecule is a preliminary step of decomposition while complete decomposition occurs with the evolution of gaseous products. Nowadays, nano-transition metals with spinel structures having ferrimagnetic properties and high catalytic activity are used as an additive for AN-type propulsion systems to reduce their thermal decomposition temperature, attracting considerable interest in rocket propellant systems.…”