Navigation Links
Finding explosives with laser beams
Date:2/27/2012

This release is available in German.

People like to keep a safe distance from explosive substances, but in order to analyze them, close contact is usually inevitable. At the Vienna University of Technology, a new method has now been developed to detect chemicals inside a container over a distance of more than a hundred meters. Laser light is scattered in a very specific way by different substances. Using this light, the contents of a nontransparent container can be analyzed without opening it.

Scattered Light as a "Chemical Fingerprint"

"The method we are using is Raman-spectroscopy", says Professor Bernhard Lendl (TU Vienna). The sample is irradiated with a laser beam. When the light is scattered by the molecules of the sample, it can change its energy. For example, the photons can transfer energy to the molecules by exciting molecular vibrations. This changes the wavelength of the light and thus its colour. Analyzing the colour spectrum of the scattered light, scientists can determine by what kind of molecules it must have been scattered.

Measuring over Great Distances with Highest Precision

"Until now, the sample had to be placed very close to the laser and the light detector for this kind of Raman-spectroscopy", says Bernard Zachhuber. Due to his technological advancements, measurements can now be made over long distances. "Among hundreds of millions of photons, only a few trigger a Raman-scattering process in the sample", says Bernhard Zachhuber. These scattered particles of light are scattered uniformly in all directions. Only a tiny fraction travel back to the light detector. From this very weak signal, as much information as possible has to be extracted. This can be done using a highly efficient telescope and extremely sensitive light detectors.

In this project (funded by the EU) the researchers at TU Vienna collaborated with private companies and with partners in public safety, including The Spanish Guardia Civil who are are extremely interested in the new technology. During the project, the Austrian military was also involved. On their testing grounds the researchers from TU Vienna could put their method to the extreme. They tested frequently used explosives, such as TNT, ANFO or RDX. The tests were highly successful: "Even at a distance of more than a hundred meters, the substances could be detected reliably", says Engelene Chrysostom (TU Vienna).

Seeing Through Walls

Raman spectroscopy over long distances even works if the sample is hidden in a nontransparent container. The laser beam is scattered by the container wall, but a small portion of the beam penetrates the box. There, in the sample, it can still excite Raman-scattering processes. "The challenge is to distinguish the container's light signal from the sample signal", says Bernhard Lendl. This can be done using a simple geometric trick: The laser beam hits the container on a small, well-defined spot. Therefore, the light signal emitted by the container stems from a very small region. The light which enters the container, on the other hand, is scattered into a much larger region. If the detector telescope is not exactly aimed at the point at which the laser hits the container but at a region just a few centimeters away, the characteristic light signal of the contents can be measured instead of the signal coming from the container.

The new method could make security checks at the airport a lot easier but the area of application is much wider. The method could be used wherever it is hard to get close to the subject of investigation. It could be just as useful for studying icebergs as for geological analysis on a Mars mission. In the chemical industry, a broad range of possible applications could be opened up.


'/>"/>

Contact: Florian Aigner
florian.aigner@tuwien.ac.at
43-158-801-41027
Vienna University of Technology
Source:Eurekalert  

Related biology news :

1. Football findings suggest concussions caused by series of hits
2. Findings prove Miscanthus x giganteus has great potential as an alternative energy source
3. New findings by St. Michaels researchers about the way cells work
4. Spasticity gene finding provides clues to causes of nerve cell degeneration
5. Sensational bird finding in China
6. Senses of sophistication: Mosquitoes detect subtle cues finding food, spreading diseases
7. The leading edge of stress: New genomic, optogenetic and epigenetic findings
8. Texas Biomed develops new approach to study depression; finding may lead to new marker for risk
9. UH engineers finding new ways to fight malaria with DOD grant
10. New findings validate the accuracy of autism diagnosis in children with Down syndrome
11. Finding relief in ritual
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Finding explosives with laser beams
(Date:2/21/2017)... LONDON , February 21, 2017 ... um 70 Millionen US-Dollar wachsen. Nach einem Gespräch mit mehr ... es einige Hindernisse zu überwinden gilt, um diese Prognose ... ... unter anderem die Mobilisierung der finanziellen Mittel für die ...
(Date:2/13/2017)... , Feb. 13, 2017 Former 9/11 Commission ... Judiciary Committee, Janice Kephart of Identity Strategy ... Donald Trump,s "Executive Order: Protecting the Nation ... 27, 2017):  "As President Trump,s ,Travel Ban, ... has now essentially banned the travel ban, it is ...
(Date:2/8/2017)... BEDFORD, Mass., Feb. 7, 2017  Aware, Inc. (NASDAQ: ... services, today reported financial results for its quarter and year ... fourth quarter of 2016 was $3.9 million compared to $6.9 ... the fourth quarter of 2016 was $0.6 million compared to ... in the fourth quarter of 2016 was $0.5 million, or ...
Breaking Biology News(10 mins):
(Date:2/24/2017)... -- VWR Corporation (NASDAQ: VWR), the leading global independent provider of ... reported its financial results for the fourth quarter and full ... 4Q16 record quarterly net sales of $1.13 billion, ... 4Q16 EMEA-APAC segment net sales ... Americas net sales increased 2.5%, or down 0.9% on an ...
(Date:2/23/2017)... 23, 2017 /PRNewswire/ - The Fight Against Cancer Innovation ... (OICR) are pleased to report that Fusion Pharmaceuticals Inc. ... Johnson & Johnson Innovation – JJDC, Inc. (JJDC) as ... HealthCap, TPG Biotechnology Partners, and Genesys Capital, as well ... ...
(Date:2/23/2017)... ... February 23, 2017 , ... ... novo clearance to begin marketing the SPEAC® System, the Brain Sentinel® Seizure Monitoring ... home or in healthcare facilities during periods of rest. A lightweight, non-invasive monitor ...
(Date:2/23/2017)... -- Capricor Therapeutics, Inc. (NASDAQ: CAPR), a biotechnology company developing biological ... Linda Marbán, Ph.D, president and chief executive officer, is scheduled ... Cowen and Company 37th Annual Health Care Conference Tuesday, ... MA 29th Annual ROTH Conference ... ET) Dana Point, CA ...
Breaking Biology Technology: