1st atom laser - Update

["Sandy Perle" <sandyfl@ix.netcom.com>]

This is an update to the earlier posted story...
-------------------

 WASHINGTON, Jan. 27  -- The world's first atom laser which shoots  
highly controlled particles of matter rather than light has been built
at the Massachusetts Institute of Technology, physicists reported
Monday. 
 Experts suggest the achievement may lead to more precise navigation 
equipment and machine tools as well as smaller, more efficient
computer chips. 
 The Cambridge, Mass.-based researchers published their findings in 
the current issue of Physical Review Letters and in Thursday's issue
of the journal Science. 
 Wolfgang Ketterle, senior researcher on the project, described the 
discovery as ``exceeding all expectations.'' The laser is based on
predictions made 70 years ago by Albert Einstein and Indian physicist
Satyendra Nath Bose, but no one was sure such a device could ever be
made. 
 The more familiar photon laser, which shoots particles of light, was 
discovered in 1960. Thirty-five years later, its presence is nearly
ubiquitous in grocery scanners, CD players, communications, etching
machines, cosmetic surgery, and other applications. 
 In contrast, the new laser shoots atoms. Both kinds of lasers, 
however, line up the particles into what Ketterle calls ``one coherent
dance.'' They are synchronized in wavelength and phase rather than
randomly flitting around. 
 The atom laser uses ultracold particles of sodium. At temperatures 
more than a million times colder than outer space, atoms lose their
individuality and begin acting as one. This new state of matter,
called Bose-Einstein concentrate or BEC, was first reported in July
1995 by physicists at the National Institute for Standards and
Technology and the Unversity of Colorado. 
 ``I don't think any of us thought this (atom laser) would happen, if 
 ever, for at least several years,'' said Randall Hulet of Rice 
University in Houston. ``It's a really incredible demonstration.'' 
 Atoms in BEC state require a magnetic trap inside a vacuum chamber to
  isolate them from the ``scorching'' temperatures of the everyday
world. The achievement of Ketterle's group was to extract sodium BEC
from the magnetic trap in a controlled fashion and show that they were
still coherent. 
 Ketterle's graduate student, Michael Andrews, said BEC particles 
``all like to be in the same state of motion, or do the same thing''
because even particles of matter share some of the wave-like behavior
of light, radio waves, and other types of energy. Normally, the atoms
are too far apart and their wavelengths are much too small for this
characteristic to noticeably influence them. 
 But as atoms are cooled to near -460 degrees Fahrenheit (-273 degrees
  
Celsius) -- called absolute zero, where all motion stops -- their
wavelengths eventually match the distance they are to one another.
They fall into synch, and begin behaving as one entity. 
 And when particles are coherent, they become highly predictable and 
controllable. 
 What Andrews describes as ``the ultimate control of matter'' will 
help physicists better isolate and understand the influences that
atoms experience. 
 ``Atomic clocks are essential for state-of-the-art navigation  
systems,'' Andrews said. Global-positioning satellites use these
highly precise timekeepers to pinpoint locations, for example. Ever
finer calibrations will reduce margins of error. 
 William Phillips of NIST in Gaithersburg, Md., said he currently sees
  the best opportunity in nanotechnology. The tiny wavelength of the
atom laser may ``do better writing on permanent structures such as
computer chips,'' he said, packing in more memory or functions on
chips of current technology. 
 Even nanomachines -- molecular structures with moving parts -- may 
cross the threshold from science fiction to reality. 
 ``I don't know how realistic that is, but we're now at the stage 
where we can find out,'' Phillips said. ``No one knew what a photon
laser was good for in 1960 either.'' 

Sandy Perle
Technical Director
ICN Dosimetry Division
Office: (800) 548-5100 Ext. 2306 
Fax: (714) 668-3149

E-Mail: sandyfl@ix.netcom.com    

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