Portable standoff Raman system for fast detection of homemade explosives through glass, plastic, and water

Anupam K. Misra; Shiv K. Sharma; Tayro E. Acosta; John N. Porter; Paul G. Lucey; David E. Bates

doi:10.1117/12.919647

4 May 2012 Portable standoff Raman system for fast detection of homemade explosives through glass, plastic, and water

Anupam K. Misra, Shiv K. Sharma, Tayro E. Acosta, John N. Porter, Paul G. Lucey, David E. Bates

Proceedings Volume 8358, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XIII; 835811 (2012) https://doi.org/10.1117/12.919647
Event: SPIE Defense, Security, and Sensing, 2012, Baltimore, Maryland, United States

Abstract

The University of Hawaii has been developing portable remote Raman systems capable of detecting chemicals in daylight from a safe standoff distance. We present data on standoff detection of chemicals used in the synthesis of homemade explosives (HME) using a portable standoff Raman system utilizing an 8-inch telescope. Data show that good-quality Raman spectra of various hazardous chemicals such as ammonium nitrate, potassium nitrate, potassium perchlorate, sulfur, nitrobenzene, benzene, acetone, various organic and inorganic chemicals etc. could be easily obtained from remote distances, tested up to 120 meters, with a single-pulse laser excitation and with detection time less than 1 μs. The system uses a frequency-doubled Nd:YAG pulsed laser source (532 nm, 100 mJ/pulse, 15 Hz, pulse width 10 ns) capable of firing a single or double pulse. The double-pulse configuration also allows the system to perform standoff LIBS (Laser-Induced Breakdown Spectroscopy) at 50 m range. In the standoff Raman detection, the doublepulse sequence simply doubles the signal to noise ratio. Significant improvement in the quality of Raman spectra is observed when the standoff detection is made with 1s integration time. The system uses a 50-micron slit and has spectral resolution of 8 cm^-1. The HME chemicals could be easily detected through clear and brown glass bottles, PP and HDPE plastic bottles, and also through fluorescent plastic water bottles. Standoff Raman detection of HME chemical from a 10 m distance through non-visible concealed bottles in plastic bubble wrap packaging is demonstrated with 1 s integration time. Possible applications of the standoff Raman system for homeland security and environmental monitoring are discussed.

Citation Download Citation

Anupam K. Misra, Shiv K. Sharma, Tayro E. Acosta, John N. Porter, Paul G. Lucey, and David E. Bates "Portable standoff Raman system for fast detection of homemade explosives through glass, plastic, and water", Proc. SPIE 8358, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XIII, 835811 (4 May 2012); https://doi.org/10.1117/12.919647

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available