Subscribe free to our newsletters via your
. Military Space News .

Subscribe free to our newsletters via your

ORNL Demonstrates Super-Sensitive Explosives Detector

File photo: Credit: AFP
by Staff Writers
Oak Ridge TN (SPX) Jul 01, 2008
Using a laser and a device that converts reflected light into sound, researchers at the Department of Energy's Oak Ridge National Laboratory can detect explosives at distances exceeding 20 yards.

The method is a variation of photoacoustic spectroscopy but overcomes a number of problems associated with this technique originally demonstrated by Alexander Graham Bell in the late 1880s.

Most notably, ORNL researchers are able to probe and identify materials in open air instead of having to introduce a pressurized chamber, which renders photoacoustic spectroscopy virtually useless for security and military applications.

ORNL's technique, detailed in Applied Physics Letters 92, involves illuminating the target sample with an eye-safe pulsed light source and allowing the scattered light to be detected by a quartz crystal tuning fork.

"We match the pulse frequency of the illuminating light with the mechanical resonant frequency of the quartz crystal tuning fork, generating acoustic waves at the tuning fork's air-surface interface," said Charles Van Neste of ORNL's Biosciences Division. "This produces pressures that drive the tuning fork into resonance."

The amplitude of this vibration is proportional to the intensity of the scattered light beam falling on the tuning fork, which because of the nature of quartz creates a piezoelectric voltage.

Van Neste and co-authors Larry Senesac and Thomas Thundat note that other advantages of quartz tuning fork resonators include compact size, low cost, commercial availability and the ability to operate in field conditions environments.

For their experiments, researchers used tributyl phosphate and three explosives - cyclotrimethylenetrinitromine, trinitrotoluene, commonly known as TNT, and pentaerythritol tetranitrate. They were able to detect trace residues with lasers 100 times less powerful than those of competing technologies.

While the researchers have been able to detect explosives at 20 meters, using larger collection mirrors and stronger illumination sources, they believe they can achieve detection at distances approaching 100 meters.

This research was funded by DOE's Office of Nonproliferation Research and Development and the Office of Naval Research. UT-Battelle manages Oak Ridge National Laboratory for the Department of Energy.

Email This Article
Comment On This Article

Share This Article With Planet Earth DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook

Related Links
Oak Ridge National Laboratory
The Long War - Doctrine and Application

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Heathrow Goes Live With Europe's First Runway Debris Detection System
London, UK (SPX) Jun 23, 2008
Heathrow, the world's busiest international airport, has invested in a state of the art radar system to further improve safety by continuously sweeping its runways for foreign objects and debris (FOD).

  • EU-Russia: Khanty-Mansiysk Engagement
  • Russian Military Strength To Drop To One Million By 2013
  • Walker's World: The new era of state rules
  • Hong Kong to launch commodities exchange next year

  • Indian PM hopes to rally support for nuclear deal: report
  • FM wishes Syria did have nuclear programme
  • New changes at top Iran security body: report
  • NKorea blows up nuke plant tower

  • US Navy Conducts First Test Of Raytheon's Standard Missile 6
  • Lockheed Gets Air Force Deal For Joint Air-To-Surface Standoff Missile Production
  • Olympics: China deploys missiles to guard Games
  • Raytheon Delivers 1,000th Tomahawk Block IV Cruise Missile To US Navy

  • Raytheon Participates In Key Satellite Payload Trade Study
  • Terminal High Altitude Area Defense Radar Successful In Missile Defense Test
  • BMD Focus: Sarkozy's vision -- Part 2
  • BMD Focus: Sarkozy's vision -- Part 1

  • European airlines angered by EU 'CO2 tax'
  • China to roll out new turboprop plane: report
  • IATA head slams EU plans to include aviation in emissions trading
  • A Plane With Wings Of Glass

  • Rockwell Collins Controls And Lands Wing-Damaged UAV
  • Predator, Reaper Unit Becomes Air Expeditionary Wing
  • UK Defence Committee Enquiry Into ISTAR And Role Of UAVs
  • Boeing Awarded Navy Contract For ScanEagle Services

  • Outside View: Iraq realities -- Part 2
  • Dogs of War: A small step for contractors
  • NATO soldier killed in Afghanistan blast
  • Outside View: Iraq realities -- Part 1

  • US Marines, Northrop Grumman Team Complete G/ATOR Preliminary Design Review
  • Australia Sees Successful Upgrades To FA-18 Hornet Capability
  • Boeing Awarded B-52 Airborne Electronic Attack Technical Maturation Contract
  • Airless Tire Project May Prove A Lifesaver In Military Combat

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement