Explosives Detection Through Opaque Containers with Agilent Resolve - a Handheld SORS System

Significance of the Topic

Rapid and non-invasive identification of concealed explosives is critical for security screening in airports, customs checkpoints, and military operations. Handheld through-barrier detection systems streamline field operations by allowing operators to assess suspicious packages without opening them, reducing risk and response time.

Objectives and Overview

This application note evaluates the performance of the Agilent Resolve handheld Raman system employing spatially offset Raman spectroscopy (SORS) to distinguish benign materials (e.g., palm oil) from a range of homemade, commercial, and military explosives hidden behind opaque or colored barriers. The goal was to demonstrate reliable identification in under one minute per sample.

Methodology and Instrumentation

The study used Agilent Resolve in through-barrier mode with the following workflow:

• Selection of container type (thick, colored, or opaque barrier) on the device.
• Optional scan delay or remote trigger and adjustable laser power settings for safety when handling primary or sensitive explosives.
• Automatic scan time adjustment based on signal strength, typically around 60 seconds per measurement.

Samples included full-size opaque plastic containers or smaller explosive samples taped inside. Primary explosives were tested in controlled field conditions with specialist support.

Main Results and Discussion

The system analyzed a variety of explosives and benign materials with high confidence:

• Explosives tested: TNT, Semtex H and A, TATB, PETN- and AN-based plastic explosives, PE4, PE7, ammonium nitrate/sugar and ammonium nitrate/fuel oil mixtures, TATP, HMTD, hydrogen peroxide/fuel blends, and primary explosive precursors.
• Priority tagging in the library allowed priority matches to be highlighted in red and secondary matches in green.
• All four illustrated measurements (palm oil, ammonium nitrate/sucrose, TNT, Semtex H) yielded clear spectral matches despite barrier interference.

The high-quality spectral correlation with library references demonstrates the robustness of SORS for through-barrier screening.

Benefits and Practical Applications

• Non-destructive, rapid screening without container breach preserves evidence and enhances operator safety.
• Portability enables deployment at checkpoints, border crossings, and field operations.
• Automated analysis and priority matching simplify operation for non-specialist users.

Future Trends and Opportunities

Advancements in SORS and handheld Raman platforms are expected to include:

• Expanded spectral libraries covering emerging synthetic threats and novel explosive formulations.
• Integration with AI-driven spectral interpretation for improved speed and accuracy.
• Enhanced barrier penetration capabilities through optimized offset geometry and laser modulation.
• Connectivity for real-time data sharing with central command and forensic laboratories.

Conclusion

The Agilent Resolve handheld SORS system reliably identifies a broad spectrum of explosive and benign materials through opaque barriers in approximately one minute. Its ease of use, rapid analysis, and non-invasive approach make it a valuable tool for security and defense applications.

Reference

Stokes R, Presly O. Explosives Detection Through Opaque Containers with Agilent Resolve—a Handheld SORS System. Agilent Technologies Application Note; 2018.