Detection of concealed and buried chemicals by using multifrequency excitations

Yaohui Gao, Meng Ku Chen, Chia En Yang, Yun Ching Chang, Jim Yao, Jiping Cheng, Stuart Yin, Rongqing Hui, Paul Ruffin, Christina Brantley, Eugene Edwards, Claire Luo

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


In this paper, we present a new type of concealed and buried chemical detection system by stimulating and enhancing spectroscopic signatures with multifrequency excitations, which includes a low frequency gradient dc electric field, a high frequency microwave field, and higher frequency infrared (IR) radiations. Each excitation frequency plays a unique role. The microwave, which can penetrate into the underground and/or pass through the dielectric covers with low attenuation, could effectively transform its energy into the concealed and buried chemicals and increases its evaporation rate from the sample source. Subsequently, a gradient dc electric field, generated by a Van De Graaff generator, not only serves as a vapor accelerator for efficiently expediting the transportation process of the vapor release from the concealed and buried chemicals but also acts as a vapor concentrator for increasing the chemical concentrations in the detection area, which enables the trace level chemical detection. Finally, the stimulated and enhanced vapors on the surface are detected by the IR spectroscopic fingerprints. Our theoretical and experimental results demonstrate that more than sixfold increase in detection signal can be achieved by using this proposed technology. The proposed technology can also be used for standoff detection of concealed and buried chemicals by adding the remote IR and/or thermal spectroscopic and imaging detection systems.

Original languageEnglish (US)
Article number043106
JournalJournal of Applied Physics
Issue number4
StatePublished - Aug 15 2010

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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