Setting out to discover new, long-lived elements

Feb 11, 2010
The picture shows the Penning trap, which is part of the Shiptrap experiment. A magnetic field parallel to the tube forces the arriving ions onto a spiral course inside the tube. The ions' spiraling frequency is used to directly calculate their atomic mass. The Penning trap is located inside the white tank that can be seen in picture 1. Credit: G. Otto, GSI Helmholtzzentrum für Schwerionenforschung

Besides the 92 elements that occur naturally, scientists were able to create 20 additional chemical elements, six of which were discovered at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt.

These new elements were produced artificially with particle accelerators and are all very short-lived: they decay in a matter of a split second. However, scientists predict the existence of even heavier elements with an extreme longevity, leaving them to only decay after years. These elements form an island of stability. Scientists at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, have developed and applied a measuring apparatus that might allow them to discover such long-lived elements, reports the renowned scientific journal Nature.

An international team of scientists headed by Michael Block was able to trap of the element 102, nobelium, in an . This is the first time in history that a so-called super heavy element had been trapped. Trapping the element allowed the research team to measure the atomic mass of Nobelium with unprecedented accuracy. The atomic mass is one of the most essential characteristics of an atom. It is used to calculate the atom's binding energy, which is what keeps the atom together. The atom's binding energy determines the stability of an atom. With the help of the new measuring apparatus, scientists will be able to identify long-lived elements on the so called islands of stability that can no longer be assigned by their . The island of stability is predicted to be located in the vicinity of the elements 114 to 120.

Michael Block, head of the research team, sets up the ion trap Shiptrap at GSI, where, for the first time, the mass of a super heavy element was measured. The measurement of nobelium (element 102) yielded an unprecedented accuracy. Credit: G. Otto, GSI Helmholtzzentrum für Schwerionenforschung

"Precisely measuring the mass of nobelium with our Shiptrap device was a successful first step. Now, our goal is to improve the measuring apparatus so that we can extend our method to heavier and heavier elements and, one day, may reach the island of stability", says Michael Block, head of the research team at the GSI Helmholtz Centre.

For their measurements, Michael Block and his team built a highly complex apparatus, the ion trap "Shiptrap", and combined it with "Ship", the velocity filter which was already used in the discovery of six short-lived elements at GSI. To produce nobelium, the research team used the GSI accelerator to fire calcium ions onto a lead foil. With the help of Ship, they then separated the freshly produced nobelium from the projectile atoms. Inside the Shiptrap apparatus, the nobelium was first decelerated in a gas-filled cell, then the slow ions were trapped in a so-called Penning trap.

Held inside the trap by electric and magnetic fields, the nobelium ion spun on a minuscule spiral course at a specific frequency. This frequency was used to calculate the atomic mass. With an uncertainty of merely 0,000005 per cent, this new technique allows determining the atomic mass and with unprecedented precision and, for the first time, directly without the help of theoretical assumptions.

Explore further: New method for non-invasive prostate cancer screening

More information:
Link to the Nature release: www.nature.com/nature/journal/… ull/nature08774.html
Link to the summary for the layman: www.nature.com/nature/journal/… 82/full/463740a.html

add to favorites email to friend print save as pdf

Related Stories

A new chemical element in the periodic table

Jun 10, 2009

The element 112, discovered at the Centre for Heavy Ion Research (GSI Helmholtzzentrum für Schwerionenforschung) in Darmstadt, has been officially recognized as a new element by the International Union of Pure and Applied ...

FAIR particle accelerator kick-off event

Nov 07, 2007

Nuclear physicists from around the world are today celebrating the official launch of the particle accelerator FAIR with a gala event and a scientific symposium. The Facility for Antiproton and Ion Research is being set up ...

Recommended for you

New method for non-invasive prostate cancer screening

12 hours ago

Cancer screening is a critical approach for preventing cancer deaths because cases caught early are often more treatable. But while there are already existing ways to screen for different types of cancer, ...

How bubble studies benefit science and engineering

13 hours ago

The image above shows a perfect bubble imploding in weightlessness. This bubble, and many like it, are produced by the researchers from the École Polytechnique Fédérale de Lausanne in Switzerland. What ...

Famous Feynman lectures put online with free access

14 hours ago

(Phys.org) —Back in the early sixties, physicist Richard Feynman gave a series of lectures on physics to first year students at Caltech—those lectures were subsequently put into print and made into text ...

Single laser stops molecular tumbling motion instantly

18 hours ago

In the quantum world, making the simple atom behave is one thing, but making the more complex molecule behave is another story. Now Northwestern University scientists have figured out an elegant way to stop a molecule from ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Parsec
not rated yet Feb 13, 2010
Too bad that the so call island of stability requires such neutron rich nuclei. Known techniques for producing heavier atoms can produce atoms of 116 protons (the center of the stability island), but the isotopes produced are very neutron poor. This is because we produce heavier nuclei by smashing together 2 lighter nuclei, and the neutron/proton ratio for stable light nuclei is usually lower than any stable heavier ones.

So while measuring these beasts is very well and good, and a nice step, actually producing them is the really hard part.