Individual atoms of a certain chemical element can be very stubborn when it comes to separation, mainly because techniques rely on a difference in chemical and physical properties — atoms are almost identical in both regards.

However, if you peer closely enough into the atoms, there are subtle differences that can have very big effects. These "different" atoms, called isotopes, are heavily relied on in areas of medicine and nuclear energy and now researchers have proposed a novel way of isolating them.

Reported today, Wednesday 29 February, in the New Journal of Physics, this new proposal combines a simple laser with a set of specifically aligned magnets to extract the desired atoms, and offers an alternative to the only general-purpose separator, called a Calutron, which is currently operating in Russia.

The researchers, from the University of Texas at Austin, propose three simple steps in their new method. The starting point is to create a flow of atoms of a particular element. Simple, low-powered lasers will then be fired at this stream of atoms, in a process called optical pumping.

After the optical pumping, the stream of optically pumped atoms would pass through a set of magnetic barriers, aligned in a specific manner. In this part of the proposed apparatus, the isotopes that researchers do not require will become attracted to the magnets and the required isotopes will pass through freely, allowing them to be collected.

Computer simulations showed the researchers' method could obtain 99.96% of lithium-7 from a sample, suggesting it would be an ideal means of getting hold of this very important isotope — lithium-7 is used in cooling water in the nuclear industry.

The most recent method used to obtain lithium-7 required enormous levels of mercury, which is a very toxic metal, and was consequently terminated at Oak Ridge National Laboratory, Tennessee.