With atoms and molecules in a gas moving at thousands of
kilometres per hour, physicists have long sought a way to slow them
down to a few kilometres per hour to trap them.
A paper, published today in the Institute
of Physics’ New Journal of Physics, demonstrates
how a group of physicists from The University of Texas at Austin, US,
have found a way to slow down, stop and explore a much wider range of
atoms than ever before.
Inspired by the coilgun that was developed by the
University’s Center for Electromechanics, the group has
developed an "atomic coilgun" that slows and gradually stops atoms with
a sequence of pulsed magnetic fields.
Dr. Mark Raizen and his colleagues in Texas ultimately plan on
using the gun to trap atomic hydrogen, which he said has been the
Rosetta Stone of physics for many years and is the simplest and most
abundant atom in the periodic table.
Work on slowing and stopping atoms has been at the forefront
of advancement in physics for some time. In 1997, there were three
joint-winners for the Nobel Prize in Physics for their combined
contribution to laser cooling - a method using laser light to cool
gases and keep atoms floating or captured in "atom traps".
These important advances had limited use because they only
applied to atoms with 'closed two-level transition', excluding
important elements such as hydrogen, iron, nickel and cobalt. In
contrast, nearly all elements and a wide range of molecules are
affected by magnetic forces, or are paramagnetic, which means that this
latest research has much wider applicability.
Professor Raizen said, "Of particular importance are the doors
being opened for our understanding of hydrogen. Precision spectroscopy
of hydrogen's isotopes, deuterium and tritium, continues to be of great
interest to both atomic and nuclear physics. Further study of tritium,
as the simplest radioactive element, also serves as an ideal system for
the study of Beta decay. "
Having successfully designed and used an 18-coil device to
slow a supersonic beam of metastable neon atoms, the team is now
developing a 64-stage device to further slow and stop atoms.