Standoff Detection of Explosives at 1 m using Laser Induced Breakdown Spectroscopy

Manoj Kumar Gundawar; Rajendhar Junjuri; Ashwin Kumar Myakalwar

doi:10.14429/dsj.67.11498

Manoj Kumar Gundawar Advanced Centre of Research in High Energy Materials, University of Hyderabad, Hyderabad - 500 046 http://orcid.org/0000-0002-4016-0354
Rajendhar Junjuri Advanced Centre of Research in High Energy Materials, University of Hyderabad, Hyderabad - 500 046
Ashwin Kumar Myakalwar Institute of Photonics and Electronics, Czech Academy of Sciences, Prague -182 51

DOI: https://doi.org/10.14429/dsj.67.11498

Keywords: Laser induced breakdown spectroscopy, Explosive detection, Principal component analysis, Multivariate analysis

Abstract

We report the ‘standoff detection’ of explosives at 1 m in laboratory conditions, for the first time in India, using Laser Induced Breakdown Spectroscopy combined with multivariate analysis. The spectra of a set of five secondary explosives were recorded at a distance of 1 m from the focusing as well as collection optics. The plasma characteristics viz., plasma temperature and electron density were estimated from Boltzmann statistics and Stark broadening respectively. Plasma temperature was estimated to be of the order of (10.9 ± 2.1) .103 K and electron density of (3.9 ± 0.5) .1016 cm-3. Using a ratiometric approach, C/H and H/O ratios showed a good correlation with the actual stoichiometric ratios and a partial identification success could be achieved. Finally employing principle component analysis, an excellent classification could be attained.

Author Biographies

Manoj Kumar Gundawar, Advanced Centre of Research in High Energy Materials, University of Hyderabad, Hyderabad - 500 046

Dr Manoj Kumar Gundawar obtained his PhD from University of Hyderabad, in 2005. Presently working as Assistant Professor at Advanced Centre of Research in High Energy Materials, University of Hyderabad. His primary research interest is spectroscopy (LIBS and Raman spectroscopy), light-matter interactions and smart instrument design based on treatment of spectroscopic data using multivariate chemometrics analysis.

He has conceived the idea presented in this paper, planned the work, and assisted in data analysis and writing the manuscript.

Rajendhar Junjuri, Advanced Centre of Research in High Energy Materials, University of Hyderabad, Hyderabad - 500 046

Mr Rajendhar Junjuri received his BSc from Kakatiya University, Warangal, in 2009 and MSc from Osmania University, Hyderabad. Currently pursuing his PhD from Advanced Centre of Research in High Energy Material, University of Hyderabad. His is currently working in the field of laser spectroscopy. The main activities includes the identification and classification of materials through Laser induced breakdown Spectroscopy (LIBS) /Raman/IR with the main focus on high energy materials, isomers and polymers.

He was involved in fine tuning of results, writing and correcting the manuscript and organising the references.

Ashwin Kumar Myakalwar, Institute of Photonics and Electronics, Czech Academy of Sciences, Prague -182 51

Dr Ashwin kumar Myakalwar has obtained his PhD (physics) from University of Hyderabad, in 2016. Currently working as a postdoctoral researcher at Institute of photonics and electronics, Prague, Czech Republic. His principal research interests are lie in the field of laser matter interaction, plasma spectroscopy, laser instrumentation, nonlinear optics, multivariate analysis, laser based methods and spectroscopy (such as LIBS, Raman, Fluorescence and IRabsorption spectroscopy).

He has assisted in performing the experiment and writing the manuscript.