By Ron B. Davis Jr., Georgetown University
By the early 1970s, West Germany had quietly built a thriving nuclear research community of its own. Universities all across the country had nuclear science programs that seemed ready to make their run at being immortalized on the periodic table. The task of consolidating these programs into one global power laboratory fell to Peter Armbruster, a senior researcher at the Helmholtz Center for Heavy Ion Research, or GSI, which was located just outside of Darmstadt, Germany.
The GSI
Peter Armbruster knew that the GSI would need an edge. He would need the best accelerator in the world, and he got it.
The device, known as the universal linear accelerator, or UNILAC, was completed near Darmstadt, taking just two years to build. The UNILAC was the most versatile linear accelerator ever built, and would allow GSI to exploit the techniques favored by both the American and Russian teams.
From 1981 to 1984, Armbruster’s program would prove a rapid success, producing the next three heavy elements in rapid succession, using low-energy fusion techniques pioneered by Oganessian. Element 24, plus element 83, created 107. Element 26 (iron), plus element 82 (lead), created 108 and element 26 plus 83 (iron plus bismuth) made 109. Thanks to Germany’s new, shiny, top-of-the line technology, there were no arguments over who discovered these three superheavy elements.
Element 107, Nielsbohrium
Element 107 was initially called nielsbohrium, after the Danish physicist, Niels Bohr. This name was unusual because, when it was in use, this was the only element to bear both the first and last name of its namesake.
Nonetheless, adding the first name in this case made some sense, when one thinks about nomenclature. After all, the last thing one might want is a chemist confusing bohrium with boron.
This was yet another naming debate that was settled in the 1990s by IUPAC, when it was decided that since no known isotope of bohrium has a half-life longer than a few minutes, it was unlikely that a lot of chemistry would be performed on it. None-the-less, students of chemistry in the early 1990s, had chemistry books with a periodic table bearing the element ‘Ns,’ or ‘nielsbohrium’ in position 107.
Lise Meitner
The naming honors for element 108 went to Hesse, the German state in which the Darmstadt lab resides, and element 109 was named for the very deserving, Lise Meitner, the prolific Austrian-born nuclear scientist, who is widely credited with the co-discovery of nuclear fission.
It is worth noting that six elements on the table had been named for female deities, and one for the husband-and-wife team of Pierre and Marie Curie, but meitnerium was the first element on the table named solely for a female scientist.
The Transfermium Working Group
Although the Germans at GIS had indisputable claim to elements 107, 108 and 109, disagreements were still raging over elements 104 through 106. Various names were being put into use regionally, and it was clear by the 1985 it was time for the IUPAC step in.
The IUPAC helped to establish a panel known as the transfermium working group, or TWG. It would be this group’s job to finally put an end to any bickering or uncertainty over the names and discovery credit for superheavy elements.
Out of this exercise came the finalized and accepted names for all elements through 109.
This article comes directly from content in the video series Understanding the Periodic Table. Watch it now, on Wondrium.
Sigurd Hofmann
Interestingly, in the 1990s the race to find new superheavy elements heated up once again. The GSI had the momentum, but American and Russian labs were close on their heels, and innovating would be critical to staying ahead.
Leading the German effort to reach even larger elements was Sigurd Hofmann. With the best accelerators already at his disposal, Hofmann turned his attention to detection, developing a new and better technique to look for the handfuls of superheavy atoms that were being prepared at GSI.
While American and Russian groups chased the next batch of superheavy elements, in a remarkable period of a little over one year, Hofmann’s attention to detector design paid off handsomely. The team successfully produced and detected three more new elements.
Darmstadtium, Roentgenium, and Copernicium
In November 1994, element 28 (Nickel) struck a lead target to form a single atom of element 110. Then the target was quickly changed from lead to bismuth, with 28 plus 83 producing three atoms of element 111, in late 1994. And a just over a year later, in February of 1996, they swapped in element 30 (zinc)—the biggest projectile yet—in a low-energy collision with lead, 30 plus 82, to form yet another single atom of element 112.
The German group’s preferred names were accepted without challenge: darmstadtium, roentgenium, and copernicium. In fact, all of six of their discoveries, stretching over a decade, were undisputed.
Only six of elements remained to be created from the seventh period, but one big challenge remained.
Three Mile Island and Chernobyl
During the remarkable breakthroughs made by Hofmann’s team until 1996, heavy-element activity elsewhere had been in a slow, steady decline. Highly publicized nuclear accidents at Three Mile Island, in 1979, and Chernobyl, in 1986, had curbed American and Russian political enthusiasm, and the short-lived products that were being observed did not seem to offer any hope of new materials for practical applications.
Post-Cold War economic woes had hit Russia’s Dubna group particularly hard. Money and physical resources were short, and the effectiveness of the low-energy fusion techniques, pioneered by Oganessian, seemed to have sputtered out around element 112.
Common Questions about the GSI and the Race to Find New Superheavy Elements
The universal linear accelerator, or UNILAC, was completed near Darmstadt, taking just two years to build.
Element 107 was initially called nielsbohrium, after the Danish physicist, Niels Bohr. This name was unusual because, when it was in use, this was the only element to bear both the first and last name of its namesake.
Highly publicized nuclear accidents at Three Mile Island, in 1979, and Chernobyl, in 1986, curbed American and Russian political enthusiasm.
