April 11, 2015

Nasa's keeping it cool, really cool

NASA's Cold Atom Laboratory (CAL), scheduled to be installed on the International Space Station early 2016, has succeeded in producing a state of matter known as a Bose-Einstein condensate, a key breakthrough for the instrument.

A Bose-Einstein condensate (BEC) is a state of matter of a dilute gas of bosons cooled to temperatures very close to absolute zero. Under such conditions, a large fraction of the bosons occupy the lowest quantum state, at which point quantum effects become apparent on a macroscopic scale.

CAL researchers used lasers to optically cool rubidium atoms to temperatures almost a million times colder than that of the depths of space. The atoms were then magnetically trapped, and radio waves were used to cool the atoms 100 times lower. The radiofrequency radiation acts like a knife, slicing away the hottest atoms from the trap so that only the coldest remain.

The research is now at the point where this process can reliably create a Bose-Einstein condensate in just seconds.

CAL is designed to study ultra-cold quantum gases on the space station. In the station's microgravity environment, interaction times and temperatures as low as one picokelvin (one trillionth of one Kelvin) should be achievable. That's colder than anything known in nature, and the experiments with CAL could potentially create the coldest matter ever observed in the universe. These breakthrough temperatures unlock the potential to observe new quantum phenomena and test some of the most fundamental laws of physics.

ScienceCasts: The Coolest Spot in the Universe

http://coldatomlab.jpl.nasa.gov/

http://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate

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