The speed of a beam of helium atoms can be controlled and slowed using an "atomic paddle" much as a tennis player uses a racquet to control tennis balls, physicists at The University of Texas at Austin have discovered.
The slow helium beam technique—a breakthrough in the field of atom optics—could someday be used to better probe microscopic surfaces or create advanced navigation systems.
"The slow beam is an enabling technology," said Dr. Mark Raizen, the Sid W. Richardson Foundation Regents Chair in Physics. "The next step is to do science with the beams."
Raizen and his colleagues at the Center for Nonlinear Dynamics created the slow helium beams using a yard-long, rapidly spinning titanium blade tipped with silicon wafers that Raizen calls an atomic paddle.
He and his colleagues 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. The beam was slowed to 560 miles per hour, less than one-eighth the normal velocity of helium.
Raizen's slow beam work is important to understanding the interaction between an atom and a surface, a fundamental aspect of physics that has been investigated since the pioneering work of Otto Stern in 1930. Scientists can bounce atoms off a surface and observe the scattered atoms to learn about the properties of the atoms and the surface.
To date, the main disadvantage of using helium to probe surfaces has been that it typically moves very quickly, nearly 4,500 miles per hour at room temperature. When helium hits a surface at a very high velocity, it tends to scatter in many directions, making it more difficult to observe the atoms after impact and limiting its practical use as a probe.
Slow beams could someday be used in advanced navigation systems with gyroscopes, like those found in airplanes, submarines, space probes and the International Space Station. Gyroscopes allow an object to maintain its orientation or balance, even in outer space.
A gyroscope system based on atoms would have a much higher sensitivity than gyroscope systems that use lasers, said Raizen.
He said that the atomic paddle method could be used in the future to produce even slower helium atoms and ultimately to stop and trap them.
Mark Raizen | EurekAlert!
UNH scientists help provide first-ever views of elusive energy explosion
16.11.2018 | University of New Hampshire
NASA keeps watch over space explosions
16.11.2018 | NASA/Goddard Space Flight Center
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Physics and Astronomy
16.11.2018 | Life Sciences
15.11.2018 | Earth Sciences