Subscribe to our free daily newsletters
  Space Industry and Business News  




Subscribe to our free daily newsletters



Radio Wave Cooling Offers New Twist On Laser Cooling

NIST physicists used radio waves to cool this silicon micro-cantilever, the narrow orange strip across the middle of this colorized micrograph. The cantilever, created by ion etching through a silicon wafer, lies parallel to a silicon radio-frequency electrode.
by Staff Writers
Gaithersburg MD (SPX) Sep 24, 2007
Visible and ultraviolet laser light has been used for years to cool trapped atoms-and more recently larger objects-by reducing the extent of their thermal motion. Now, applying a different form of radiation for a similar purpose, physicists at the National Institute of Standards and Technology (NIST) have used radio waves to dampen the motion of a miniature mechanical oscillator containing more than a quadrillion atoms, a cooling technique that may open a new window into the quantum world using smaller and simpler equipment.

Described in a forthcoming issue of Physical Review Letters, this demonstration of radio-frequency (RF) cooling of a relatively large object may offer a new tool for exploring the elusive boundary where the familiar rules of the everyday, macroscale world give way to the bizarre quantum behavior seen in the smallest particles of matter and light. There may be technology applications as well: the RF circuit could be made small enough to be incorporated on a chip with tiny oscillators, a focus of intensive research for use in sensors to detect, for example, molecular forces.

The NIST experiments used an RF circuit to cool a 200 x 14 x 1,500 micrometer silicon cantilever-a tiny diving board affixed at one end to a chip and similar to the tuning forks used in quartz crystal watches-vibrating at 7,000 cycles per second, its natural "resonant" frequency. Scientists cooled it from room temperature (about 23 degrees C, or 73 degrees F) to -228 C (-379 F).

Other research groups have used optical techniques to chill micro-cantilevers to lower temperatures, but the RF technique may be more practical in some cases, because the equipment is smaller and easier to fabricate and integrate into cryogenic systems. By extending the RF method to higher frequencies at cryogenic temperatures, scientists hope eventually to cool a cantilever to its "ground state" near absolute zero (-273 C or -460 F) , where it would be essentially motionless and quantum behavior should emerge.

Laser cooling is akin to using the kinetic energy of millions of ping-pong balls (particles of light) striking a rolling bowling ball (such as an atom) to slow it down. The RF cooling technique, lead author Kenton Brown says, is more like pushing a child on a swing slightly out of synch with its back-and-forth motion to reduce its arc. In the NIST experiments, the cantilever's mechanical motion is reduced by the force created between two electrically charged plates, one of which is the cantilever, which store energy like electrical capacitors.

In the absence of any movement, the force would be stable, but in this case, it is modulated by the cantilever vibrations. The stored energy takes some time to change in response to the cantilever's movement, and this delay pushes the cantilever slightly out of synch, damping its motion.

Related Links
National Institute of Standards and Technology (NIST)
Space Technology News - Applications and Research



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


Laser Sets Records In Power And Energy Efficiency
Evanston IL (SPX) Jul 27, 2007
The rise in global terrorism in recent years has brought significant attention to the needs for more advanced sensors and defense technologies to protect civilians and soldiers. Next-generation laser-based defense systems are now being designed for this need, including the use of infrared countermeasures to protect aircraft from heat-seeking missiles and highly sensitive chemical detectors for reliable early detection of trace explosives and other toxins at a safe distance for personnel.







  • US cities' Wi-Fi dreams fading fast
  • Digital Dandelions: The Flowering Of Network Research
  • Researchers Aim To Make Internet Bandwidth A Global Currency
  • Controlling Bandwidth In The Clouds

  • Pratt And Whitney Rocketdyne's RS-27A Powers New-Gen Imaging Satellite To Orbit
  • United Launch Alliance Launches 75th Consecutive Delta II On USAF 60th Anniversary
  • Russian Space Launch Vehicle Firing Tests Set For 2008
  • Arianespace To Launch Japanese Satellite JCSAT-12

  • Cathay Pacific chief hits out at anti-aviation critics
  • Squabble over airline carbon emissions takes flight
  • Boeing Projects 340 Billion Dollar Market For New Airplanes In China
  • KC-30 Tanker's General Electric Power Plant Completes One Million Takeoff And Landing Cycles

  • China's military tests sophisticated real-time data system
  • ThalesRaytheonSystems To Provide Upgrade For Battle Control System
  • Northrop Grumman Receives Major Contract For Guardrail Modernization
  • Boeing Demonstrates FAB-T Interoperability With Milstar Satellite

  • Radio Wave Cooling Offers New Twist On Laser Cooling
  • SSC Communication System Flys On Russian Capsule Foton
  • Engineers Rescue Aging Satellites And Save Millions
  • Russian Satellites: Smaller, Lighter, Cheaper

  • Analysis: Sulick new head spy for CIA
  • Raytheon Names Dr. Thomas Kennedy VP Tactical Airborne Systems
  • Northrop Grumman Appoints James Myers VP And GM Of Navigation Systems Division
  • Senior Official Of Energia Space Appointed President

  • Boeing Launches WorldView-1 Earth-Imaging Satellite
  • New Faraway Sensors Warn Of Emerging Hurricane's Strength
  • Key Sensor For Northrop Grumman NPOESS Program Passes Critical Structural Test
  • Air France And ESA Join To Offer Passengers Unique View Of Voyage

  • Brussels to present finance plans to save Galileo satnav project
  • DoD Permanently Discontinues Procurement Of Global Positioning System Selective Availability
  • Boeing Builds First GPS IIF Satellite
  • Lockheed Martin Team Shifts Into Production Effort To Add GPS Demonstration Signal To Modernized Satellite

  • The content herein, unless otherwise known to be public domain, are Copyright Space.TV Corporation. 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 Space.TV Corp on any Web page published or hosted by Space.TV Corp. Privacy Statement