New laser technique may help find supernova

Aug 11, 2009

One single atom of a certain isotope of hafnium found on Earth would prove that a supernova once exploded near our solar system. The problem is how to find such an atom - among billions of others. Researchers at the University of Gothenburg, Sweden, have developed a laser technique that, in combination with standard techniques, may be able to do the job.

Hafnium is a common metallic element used in nuclear reactors. However, one of its is hard to find since it is only made when a supernova explodes. This means that if the isotope, called 182Hf, were discovered on Earth, it would prove that a once exploded near our . This has caused physicists around the world to work hard to find the isotope.

Unfortunately, this particular isotope is difficult to distinguish from other atoms - only one in many billions of hafnium atoms is believed to be of the sought-after kind. Researcher Pontus Andersson from the Department of Physics at the University of Gothenburg and colleagues from USA, Germany and Austria have developed a technique that can be used to reject irrelevant atoms, and therefore isolate the unique 182Hf.

In technical terms, their new technique concerns negative ions, which are atoms or molecules with one extra electron. By using laser to detach the extra electron and at the same time register the level of energy needed to do this, it is known that the strength of the bond between the extra electron and the rest of the atom or molecule varies among different substances.

This means that by choosing a certain wavelength of the laser light, they can detach the extra electron from some elements while ions of other elements remain intact. Consequently, if 182Hf exists on Earth, then Andersson and his colleagues should be able to find it, simply by using laser light to remove sufficient amount of other, more common, interfering atoms, to allow detection of 182Hf by conventional methods.

The new technique is a product of advanced atomic physics experiments conducted together with Stockholm University, The VERA institute i Vienna, Austria and Oak Ridge National Lab in USA.

'Our goal is to develop a method that can be of aid when searching for very unusual isotopes. In many cases the standard methods used are hampered by other, interfering . The technique is still in its infancy, but we have shown that our laser beam can remove 99.99 % of the interfering ions in a beam without destroying the ions we are looking for', says Andersson.

Source: University of Gothenburg (news : web)

Explore further: A two-stage trap for single protons leads to measurement of their magnetic properties

add to favorites email to friend print save as pdf

Related Stories

Physicists Ponder Atoms Without Nuclei

Mar 19, 2008

You might remember learning in sixth grade science class that isotopes are atoms that have lost or gained a few neutrons, and ions are atoms that have lost or gained a few electrons. But what about an atom ...

Stopping atoms

Oct 03, 2007

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 Quantum Mechanical 'Tune Up' for Better Measurement

Jun 05, 2004

By exploiting the weird quantum behavior of atoms, physicists at the Commerce Department’s National Institute of Standards and Technology (NIST) have demonstrated a new technique that someday could be used to save weeks ...

Controlling most atoms now possible

Mar 06, 2008

Stopping and cooling most of the atoms of the periodic table is now possible using a pair of techniques developed by physicist Mark Raizen at The University of Texas at Austin.

Trapping Erbium Atoms: The Impossible Made Possible

Apr 19, 2006

Recycling atoms? Can they do that? In a world where nearly everything can be reused, scientists are moving forward with a novel approach to using Magneto-Optical Traps (MOTs) to, in effect, recycle atoms. In a L ...

Recommended for you

50-foot-wide Muon g-2 electromagnet installed at Fermilab

Jul 31, 2014

One year ago, the 50-foot-wide Muon g-2 electromagnet arrived at the U.S. Department of Energy's Fermi National Accelerator Laboratory in Illinois after traveling 3,200 miles over land and sea from Long Island, ...

User comments : 0