The Heavy Ion Society (Gesellschaft für Schwerionenforschung, GSI) in Darmstadt, Germany, has dedicated its mission to slamming together heavy nuclei to produce even heavier nuclei.
For that purpose they use UNILAC, the 120-meter long Universal Linear Accelerator which accelerates ions to 20 percent of the speed of light to smash them on lead targets, and SHIP, the Separator for Heavy Ion reaction Products, an electromagnetic separator and detector assembly which is used to analyse the reaction products.
During the last decades, the GSI has thus become known with their discovery of new chemical elements in the periodic table. The latest one, element 112, has now been named "Copernicium," after astronomer Nicolaus Copernicus.
Previous ones were named Bohrium (element 107, named after Niels Bohr), Hassium (element 108, after the Latin name for the state Hesse, where GSI is located), Meitnerium (element 109, after Lise Meitner), Darmstadtium (element 110, after the city Darmstadt), and Roentgenium (element 111, after Wilhem Röntgen). These elements have a half-life ranging from seconds to minutes.
The element 112 (112-277) has been produced for the first time in fusion reactions of zinc-70 (with proton number 30) projectiles with lead-208 (proton number 82) targets. In a three weeks' experiment which ran 24 hours per day, one nucleus of element 112 was first observed on February 9, 1996. The nucleus disintegrates in a series of α-decays, which allows its identification:
The half-life of the new element Copernicium is not yet clear due to lacking statistics. But the discovery could be reproduced in other laboratories in Russia and Japan. Here is a photo of the proud discoverers (Credits: A. Zschau, GSI):
Sigurd Hofmann, the leader of the SHIP group at GSI, has given a talk about these dicoveries at the American Chemical Society meeting in San Diego, in 2001, to which you can listen here.
Besides the fun it brings to slam together heavy things, these experiments have the scientific purpose of better understanding the structure of elementary matter. Eventually, you know, physicsts want to derive all chemistry from QCD, but we're far away from that. The heavy ion beams produced at the GSI have also been used since 1997 for cancer treatment.
One theory that has been around for several decades is that at sufficiently high number of protons and neutrons the stability of elements will increase dramatically. In the periodic system, this patch has been dubbed the (conjectured) "Island of Heavy Nuclei." Its position shifted a bit with new models for nuclear structure, but it's still believed to be there, somewhere above atomic number 120.
I've always found this intriguing. Imagine, once we've crossed the valley of short-lived elements, we could produce some elements stable enough to form molecules and create chemical reactions that aren't taking place by natural processes anywhere in the known universe. Granted, serious nuclear physicists don't believe they would be that stable, but likely undergo spontaneous fission. But still, it would make for a nice science-fiction scenario, wouldn't it? A completely new kind of chemistry.
The New Element 112.
Zeitschrift für Physik A 354, 229-230 (1996), DOI 10.1007/BF02769517.