Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ultrafast lasers take ’snapshots’ as atoms collide

21.10.2005


Using laser pulses that last just 70 femtoseconds (quadrillionths of a second), physicists have observed in greater detail than ever before what happens when atoms collide. The experiments at JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder, confirm a decades-old theory of how atoms--like tennis balls--briefly lose form and energy when they hit something. The results will help scientists study other atomic-scale processes and better understand the laws of physics.


JILA scientists used brief flashes of laser light to reveal how atoms, like tennis balls, briefly lose form and energy when they collide. Image credit: V. Lorenz, JILA



The new data, reported in the Oct. 14 issue of Physical Review Letters,* provide the equivalent of missing frames in movies of colliding atoms (see simulated images in accompanying graphic). As is the case when a tennis ball is hit by a racquet, the motion is too quick for the eye but can be detected using short flashes of light. The JILA scientists collected data on atoms’ properties before, during and after collisions lasting just half a picosecond (trillionth of a second) using laser "flashes" that were even faster.

In the JILA experiments, about 10 quintillion potassium atoms in a dense gas were packed into a titanium container just 1 square centimeter in size and heated to 700 degrees C (almost 1,300 degrees F). With such high temperatures and large numbers of atoms, the experiment is designed to maximize the number of atom collisions. Rapidly alternating pulses of laser light then are used to "freeze frame" the action.


Energy from the first laser pulse is absorbed by the atoms, placing them in a uniform state, emitting electromagnetic waves in identical patterns. A second laser then quickly hits the mass of atoms, and a detector captures a signal beam formed by the interaction of the beams. Light from the second pulse is absorbed and re-emitted by atoms that are "in synch" but not by atoms that are colliding and losing energy. The intensity of this signal beam, measured as a function of the delay between the two pulses, provides a "snapshot" of how many atoms are colliding at any one time, as well as details about changes in their wave patterns.

Laura Ost | EurekAlert!
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>