Portable detection system for standoff sensing of explosives and hazardous materials

Sharma, Ramesh C.; Kumar, Deepak; Bhardwaj, Neha; Gupta, Saurabh; Chandra, Hukum; Maini, Anil K.

doi:10.1016/j.optcom.2013.06.025

Cited by 40 publications

(19 citation statements)

References 11 publications

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“…The work of Sharma et al revealed that stand-off distance was dependent on the background substrate material. DNT and PETN on diffused Al, scanned over 1160-1400 cm − 1 and 880-915cm −1 , had a 5 μg cm −2 sensitivity with 12 m range, whereas a wood surface required 50 μg cm −2 to yield only a 6 m range [211]. Short stand-off detection (8 inches) of bulk TNT (1 mg mm −2 ) was obtained using an ultrasensitive microphone, and increased to 2.5 m using a 0.6 m diameter parabolic sound reflector [202,206].…”

Section: Photoacoustic Spectroscopymentioning

confidence: 98%

Advances in explosives analysis—part II: photon and neutron methods

et al. 2015

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The number and capability of explosives detection and analysis methods have increased dramatically since publication of the Analytical and Bioanalytical Chemistry special issue devoted to Explosives Analysis [Moore DS, Goodpaster JV, Anal Bioanal Chem 395:245-246, 2009]. Here we review and critically evaluate the latest (the past five years) important advances in explosives detection, with details of the improvements over previous methods, and suggest possible avenues towards further advances in, e.g., stand-off distance, detection limit, selectivity, and penetration through camouflage or packaging. The review consists of two parts. Part I discussed methods based on animals, chemicals (including colorimetry, molecularly imprinted polymers, electrochemistry, and immunochemistry), ions (both ion-mobility spectrometry and mass spectrometry), and mechanical devices. This part, Part II, will review methods based on photons, from very energetic photons including X-rays and gamma rays down to the terahertz range, and neutrons.

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Section: Photoacoustic Spectroscopymentioning

confidence: 98%

Advances in explosives analysis—part II: photon and neutron methods

et al. 2015

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“…The laser energy is expressed as [10,11] , k is the atmosphere transmission; a is the environment attenuation coefficient; g is the reflectivity of the target; Transmitter h and Re ceiver h are the optical efficiency of the transmitter and receiver, respectively; D is the diameter of concave mirrors; and tan dis ce S is the distance between the tuning fork and detected objects.…”

Section: Model Of Laser Power Densitymentioning

confidence: 99%

Dynamics of quartz tuning fork force sensors used in standoff photoacoustic detection

Zhang

Jia

et al. 2015

J Mech Sci Technol

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In this paper, a two-degrees-of-freedom model with two coupled oscillators is established to study the dynamics of quartz tuning fork force sensors. Air squeeze-film damping is considered in this model. When the laser power is 40 mW and the distance between the tuning fork and detected objects is approximately 0.5 m, the resonance amplitude of the tuning fork under the electromagnetic radiation pressure of the laser can reach 0.22 pm. Electromagnetic radiation pressure and resonance amplitude have the tendency to exponentially decay along with the distance between the tuning fork and detected objects. The influence of laser power and distance between the tuning fork and detected objects on electromagnetic radiation pressure is also considered. Lastly, an experimental device is set up to verify the calculation result of the model. Analysis shows that the experimental data are in good agreement with the theoretical calculation results.

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“…This output signal can read by the lock-in amplifier. The pre-amplifier circuit consists of Quartz Crystal Tuning Fork (QCTF) detector [3]. The detector is mounted on the PCB based pre-amplifier circuit shown in Figure 2.…”

Section: Ad829 Based Pre-amplifier Circuitmentioning

confidence: 99%

“…32.8 KHz), which acts as a detector, and enables total insensitivity to ambient CW radiations. Details of the technique are explained in reference [1][2][3]. The main advantages of this technique is that it offers standoff detection of low concentration (up to ppb level) of chemicals/ explosives without using a sample collection step, by the detection of trace quantities of surface adsorbed chemicals/explosives [4][5][6].…”

Section: Introductionmentioning

confidence: 99%