U.S. physicists report they can now control the speed of a beam of helium atoms using an 'atomic paddle.'

Scientists at the University of Texas at Austin said their technique could someday be used to better investigate microscopic surfaces or create advanced navigation systems.

Mark Raizen and colleagues at the university's Centre for Non-linear Dynamics created the slow helium beams using a yard-long, rapidly spinning titanium blade tipped with silicon wafers that Raizen calls an atomic paddle.

The team pumped puffs of super-cooled helium gas into a vacuum chamber containing the paddle using supersonic beam technology developed by Professor Uzi Even of Tel Aviv University. The paddle's silicon wafers reflected the helium atoms much like a glass mirror reflects a beam of light.

Just as the energy of a tennis ball is absorbed by the motion of a tennis racquet, the motion of the paddle absorbed the energy from the helium beam, slowing it to 560 miles per hour, less than one-eighth the normal velocity of helium. $quot;The slow beam is an enabling technology,$quot; said Raizen. $quot;The next step is to do science with the beams.$quot;