Compound Explosives Detection and Component Analysis via Terahertz Time-Domain Spectroscopy

Choi, Jindoo; Ryu, Sung Yoon; Kwon, Won Sik; Kim, Kyung-Soo; Kim, Soohyun

doi:10.3807/josk.2013.17.5.454

Cited by 36 publications

(18 citation statements)

References 27 publications

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“…THz spectroscopy and imaging were actively used for this purpose during the past twenty years in the wide area of security applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. At the same time, this technique starts to be widely used for the non-destructive testing, for quality inspection of pharmaceuticals and food products as well as for medical applications [20][21][22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

High effective THz-TDS method for the detection and identification of substances in real conditions

et al. 2016

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Low efficiency of the standard THz-TDS method for the detection and identification of substances is demonstrated. For this purpose, we use a few examples. In the first example, we model the noisy THz signals transmitted through the amphetamine-type stimulant in real conditions. Namely, with a temperature 18° C, the relative humidity of about 50 % and the distance between the parabolic mirror and the object about of 3.5 meters. We show that the standard THz-TDS method reveals the spectral features of many neutral substances and explosives in the noisy THz signals from the illicit stimulant MA, at the same time this method is not able to detect the presence of this stimulant in the noisy signals. The second example is the detection and identification of plastids with inhomogeneous surface in reflection mode. We show that inhomogeneous surface distorts spectral characteristics of the reflected THz signal main pulse, which cannot be used for the detection and identification of the plastids by means of the THz TDS method. In the last example we show that even under laboratory conditions (at short distance from the receiver), THz TDS detects in the semiconductors the absorption frequencies, which belong to both hazardous and neutral substances. To overcome this disadvantage, we propose to use the time-dependent spectrum of the THz pulse, transmitted through or reflected from a substance. For quality assessment of the presence of the standard substance absorption frequency in the signal under analysis, we use time-dependent integral correlation criteria. The influence of aperture placed in front of the sample on spectral properties of silicon wafers with different resistivity is demonstrated as well.Keywords: reflected and transmitted THz pulse, noisy THz pulse, method of spectral dynamics analysis, integral correlation criteria, identification of explosives and drugs. *vatro@cs.msu.ru; phone 7 495 939-5255; fax 7 495 939-2597

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Section: Introductionmentioning

confidence: 99%

High effective THz-TDS method for the detection and identification of substances in real conditions

et al. 2016

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“…A great deal of research has been performed on the spectral signatures of explosives and related materials through THz TDS, including the conventional molecular explosives RDX, HMX, PETN, and simulant molecules [23][24][25][26][27][28]. Likewise, the spectral signatures of explosive mixtures and plastic compositions have been studied [26][27][28][29][30][31][32][33]. Additionally, spectral signatures of homemade explosives and related materials have been analyzed [34][35][36].…”

Section: Terahertz Spectroscopy and Imagingmentioning

confidence: 99%

“…), surface roughness of the samples, and water vapor or humidity present in the air [30,37]. Many researchers have addressed these challenges through developing methods to separate spectral fingerprints of explosives from barrier materials [30,31,[38][39][40], and signal-processing algorithms to compensate for water-vapor absorption [32].…”

Section: Terahertz Spectroscopy and Imagingmentioning

confidence: 99%

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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“…As it is well-known, one of the promising ways to solve this problem is the use of terahertz radiation [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. It bases on the fact that the frequencies of vibrational or rotational inter-level energy transitions of many chemical compounds, including explosives, lie in the terahertz frequency range.…”

Section: Introductionmentioning

confidence: 99%

Possibility of the detection and identification of substance at long distance using the noisy reflected THz pulse under real conditions

Trofimov

Varentsova

Trofimov

2015

Terahertz Physics, Devices, and Systems IX: Advanced Applications in Industry and Defense

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We show possibility of the detection and identification of substance at long distance (several metres, for example) using the THz pulse reflected from the object under the real conditions: at room temperature and humidity of about 70%. The main feature of this report consists in a demonstration of the detection and identification of substance using the computer processing of the noisy THz pulse. Amplitude of the useful signal is less than the amplitude of a noise. Nevertheless, it is possible to detect "fingerprint" frequencies of substance if these frequencies are known and the SDA method is used together with new assessments for probability estimation for presence of detected frequencies. Essential restrictions of the commonly used THz TDS method for the detection and identification under real conditions (at long distance about 3.5 m and at a high relative humidity more than 50%) are demonstrated using the physical experiment with chocolate bar and thick paper bag. We show also that the THz TDS method detects spectral features of dangerous substances even in the THz signals measured in laboratory conditions (at distance 30-40 cm from the receiver and at a low relative humidity less than 2%); the n-Si and p-Si semiconductors were used as neutral substances. However, the integral correlation and likeness criteria, based on SDA method, allow us to detect the absence of dangerous substances in the samples. Current results show feasibility of using the discussed method of the THz pulsed spectroscopy for the counter-terrorism problem.

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Compound Explosives Detection and Component Analysis via Terahertz Time-Domain Spectroscopy

Cited by 36 publications

References 27 publications

High effective THz-TDS method for the detection and identification of substances in real conditions

High effective THz-TDS method for the detection and identification of substances in real conditions

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

Possibility of the detection and identification of substance at long distance using the noisy reflected THz pulse under real conditions

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