Continuous wave terahertz frequency spectroscopy and imaging for explosives detection and security screenings

  • Author / Creator
    Startsev, Michael Andrei
  • Continuous-wave terahertz (THz) spectroscopy was performed on high explosive materials using the Firefly-THz optical parametric oscillator (OPO). Cyclotetramethylene-tetranitramine (HMX), cyclotrimethylene-trinitramine (RDX), pentaerythritol-tetranitrate (PETN) and Composition-4 were scanned under experimental conditions modeling “real world” security screenings. Spectroscopy of RDX yielded broad spectral signatures at 0.83, 1.04, and 1.50 THz. HMX and PETN displayed singular spectral peaks of 1.45 and 1.78 THz, respectively. The OPO’s viability for use as a security system was further evaluated through demonstrations of concealed explosive spectroscopy, and raster scan imaging. A lamellar mirror interferometer was designed and constructed to investigate the system’s frequency range limitations. The interferometric scans concluded that, using Golay cell detection methods, the system could utilize coherent radiation between 0.75 and 1.8 THz. Lastly, a prototype external camera circuit was designed to further the development of a THz frequency camera system capable of both imaging and spectroscopy simultaneously.

  • Subjects / Keywords
  • Graduation date
    Fall 2011
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.