Featured Research

from universities, journals, and other organizations

Super-sensitive Explosives Detector Demonstrated

Date:
June 27, 2008
Source:
DOE/Oak Ridge National Laboratory
Summary:
Using a laser and a device that converts reflected light into sound, researchers at the US Department of Energy's Oak Ridge National Laboratory can detect explosives at distances exceeding 20 yards.

ORNL researcher Charles Van Neste (shown above) and his colleagues have developed a new method that can enable them 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.
Credit: Jason K. Richards, Photography Dept., Creative Media; courtesy of DOE/Oak Ridge National Laboratory

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.


Story Source:

The above story is based on materials provided by DOE/Oak Ridge National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. W. Van Neste, L. R. Senesac, and T. Thundat. Standoff photoacoustic spectroscopy. Applied Physics Letters, 2008; 92 (23): 234102 DOI: 10.1063/1.2945288

Cite This Page:

DOE/Oak Ridge National Laboratory. "Super-sensitive Explosives Detector Demonstrated." ScienceDaily. ScienceDaily, 27 June 2008. <www.sciencedaily.com/releases/2008/06/080625153328.htm>.
DOE/Oak Ridge National Laboratory. (2008, June 27). Super-sensitive Explosives Detector Demonstrated. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2008/06/080625153328.htm
DOE/Oak Ridge National Laboratory. "Super-sensitive Explosives Detector Demonstrated." ScienceDaily. www.sciencedaily.com/releases/2008/06/080625153328.htm (accessed April 17, 2014).

Share This



More Matter & Energy News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com
Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

TheStreet (Apr. 16, 2014) The Porsche Spyder 918 proves that, in an automotive world obsessed with fuel efficiency, the supercar is not dead. Porsche North America CEO Detlev von Platen attributes the brand's consistent sales growth -- 21% in 2013 -- with an investment in new technology and expanded performance dynamics. The hybrid Spyder 918 has 887 horsepower and 944 lb-ft of torque, but it can run 18 miles on just an electric charge. The $845,000 vehicle is not a consumer-targeted vehicle but a brand statement. Video provided by TheStreet
Powered by NewsLook.com
Industry's Optimism Shines At New York Auto Show

Industry's Optimism Shines At New York Auto Show

Newsy (Apr. 16, 2014) After seeing auto sales grow last month, there's plenty for the industry to celebrate as it rolls out its newest designs. Video provided by Newsy
Powered by NewsLook.com
Ford Mustang Fetes Its 50th Atop Empire State Building

Ford Mustang Fetes Its 50th Atop Empire State Building

AFP (Apr. 16, 2014) Ford celebrated the 50th birthday of its beloved Mustang by displaying a new model of the convertible on top of the Empire State Building in New York. Duration: 00:28 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins