New super-heavy elements created in a particle accelerator

Researchers in the US have created enlarged versions of atomic nuclei. The existence of one of the nuclei should not be possible, according to the current theory

Researchers from the University of Michigan, in a research laboratory using a superconducting cyclotron, have succeeded in creating three new isotopes of magnesium and aluminum. These results actually place 'facts in the field' that indicate the ability to create heavier atoms than the scientific models currently predict. The results of the study appeared in the prestigious Nature magazine on October 24, 2007.
The new nuclei were created by accelerating atoms to an enormous speed - half the speed of light (540,000,000 km/h) - and smashing them into each other. Another way of creating heavy nuclei, which occurs in the universe all the time, is through fusion processes within the cores of stars.
"Ever since nuclear science became an accepted theory, scientists have been trying to determine which isotopes can exist in nature," said Dave Morrissey, a professor of chemistry at the University of Michigan and one of the authors of the paper. "The result we obtained shows that it is possible to stretch the stability limits of the material more than we previously expected. In fact, it shows us how much we still don't know about the atomic nucleus."

Neutrons, protons and isotopesThe atomic nucleus consists of two types of particles - protons and neutrons. Each atom has a fixed number of protons, but the number of neutrons it possesses can vary. Isotopes are atoms of the same element (having a fixed number of protons), but having a different number of neutrons.
There are four fundamental forces, which together are able to describe the interactions between all matter in the universe. Of the four, the strong nuclear force is the one that keeps the protons and neutrons inside the nucleus. The four fundamental forces have been subject to in-depth and continuous research since 1930.
One way to learn about the strong nuclear force is by defining the maximum amount of neutrons - the largest number of neutrons that can be loaded onto a certain nucleus. This maximum amount is known only for the eight lightest elements - starting with hydrogen and ending with oxygen. So there is still no answer to the simple and basic question - what is the heaviest isotope that can exist for each element. We only know the answer for eight of the hundred-something elements on the periodic table.

shattering atomsThe researchers used a circular particle accelerator - a cyclotron. The cyclotron accelerates materials to very high speeds, then fires them at heavy atoms. The original atoms are shattered and new heavy nuclei are formed from the remnants of their encounter.
Using this technology, researchers at the University of Michigan were able to create and distinguish three new super-heavy isotopes of magnesium and aluminum:
* Magnesium-40 with 12 protons and 28 neutrons

* Aluminum-42 with 13 protons and 29 neutrons
* Aluminum-43 with 13 protons and 30 neutrons

Normal aluminum contains 14 neutrons. As a comparison, a regular aluminum cube that weighs 1600 kilogram would weigh 1.6 grams (43 kilograms) if it were composed of aluminum-42. The current theories claimed that it is unlikely that aluminum-XNUMX could exist.
"Researchers from many research institutes around the world have been searching for a long time for these isotopes, especially magnesium-40, but without success," said Thomas Bowman, physicist and lead author of the study. He added that, "The next step is to push forward and try to find the limit of the existence of the nucleus, with the aim of discovering the maximum amount of neutrons of these and other elements. For this we will have to upgrade our laboratory. The ideas and the theoretical and applied knowledge are already in our possession. We just need the money.”

For information on the University of Michigan website

Link to interview videos of the researchers regarding the discovery

Photo: Professor Dave Morrissey: "Our discovery shows how much we still don't know about the atomic nucleus."

Photo: The researchers' research notebook, open to the page where they made the discovery. Below the discovery, the researchers wrote in their joy that, "Now we can celebrate!"