Explosives DetectionThe Challenge:

Today’s forward-deployed warfighterand security professionals need to rapidly and reliably identify various compounds or residues found in the field to distinguish between inert materials and home-made explosive (HME) compounds. Forensic experts also need timely data to help identify those responsible, in order to contain the proliferation of HME attacks.

Traditional Solutions:

Raman spectroscopy has emerged as a proven technique for chemical identification, however current techniques occasionally produce erroneous readings, and do nothing to help determine  “Who made it?”  Forensic experts need data relating to ingredient sources, contaminants and methods of manufacture (or synthetic pathways), as well a insights into the formulation and storage environment which can reveal clues about where it was made. Getting this  additional information can often require  large, expensive, equipment, and special sample handling and preparation

The Ondax Solution: One Sample, One System, One Answer

ETN Low Frequency THz-Raman SpectraLow-frequency/ THz-Raman analysis can identify and differentiate synthetic pathways, ingredients, and formulations, as well as reveal changes relating to environment and storage (e.g. heat, humidity).  Each of these factors can leave behind telltale “signatures” or “fingerprints” in the molecular structure that help the forensic specialist in narrowing or accelerating their search for the perpetrator.  Ondax THz-Raman® systems extend the range of traditional Raman spectroscopy to the terahertz/low frequency regime, where differentiation of inter- and intra-molecular structures can be clearly seen. Anti-Stokes signals add to Raman intensity and improve SNR. Combining both composition and structural analysis eliminates the need for multiple samples and instruments, lowering capital, training and maintenance costs.

Features / Benefits
  • Fast, simultaneous capture of BOTH chemical AND structural information
  • Works with small traces of materials
  • Enhanced sensitivity and reliability due to additional low-frequency and anti-Stokes signals
  • Non-contact, non-destructive and requires no sample preparation
  • Works at standoff distance
  • Simple, compact, cost-effective
  • Can be miniaturized for portable or field use

HMTD Low Frequency THz-Raman Spectra
HMTD Low Frequency THz-Raman SpectraTHz-Raman analysis of HMTD (Hexamethylene Triperoxide Diamine) and Ammonium Nitrate is shown below.  The strong, distinctive peaks in the low-frequency/THz-Raman region (green background) are typically  higher than the traditional fingerprint range, adding signal, improving sensitivity and reducing false positives.  Peak symmetry about the excitation line also enables auto-calibration and enhanced system and data reliability. Ondax’s patented2  SureBlockTM THz-Raman® Spectroscopy Systems extend the range of  traditional Raman spectroscopy into the terahertz/low-frequency regime, exploring the same range of energy transitions as terahertz spectroscopy – without limiting the ability to measure the fingerprint region. This enables simultaneous  analysis of both molecular structure and chemical composition for advanced materials characterization.


TATP Low Frequency/THz-Raman Spectra

Ammonium Nitrate

Ammonium Nitrate Low Frequency/THz-Raman Spectra

Adding symmetrical THz-Raman spectra boosts SNR and provides an inherent calibration reference, improving detection reliability