By Ron B. Davis Jr., Georgetown University
Shortly after the Berkely group announced their successful synthesis of element 102, nobelium, news came from Georgy Flerov’s lab at Dubna, that the Russians had produced it as well. And yet, in doing so, they were able to show that the Americans had incorrectly measured the mass of their product, mistaking some of the fission products for element 102. It set the stage for the most vigorous and hotly contested stretch of element discovery ever, what became known as ‘the transfermium wars’.
Element 102, Nobelium
With the Swedes laying equal claim, it was the Americans who finally succeeded in creating element 102. Around this time, there was another, even more formidable international competitor who was just beginning to flex its muscle. Located in Dubna, north of Moscow, Georgy Flerov’s lab at the Joint Institute for Nuclear Physics was hot on the heels of both groups, and they were keen to take advantage of a flaw even in the American experiment.
When element 102 was discovered, even though the name, nobelium, given by the Americans, was no longer in dispute, the credit for its actual discovery became part of a three-way dispute. It was a kind of dispute that could probably never be formally settled. In any case, the race to discover new heavy metals and expand the periodic table continued.
In the periodic table, collectively, the 15 elements from the seventh row beyond lawrencium are referred to as the ‘superheavy’ elements, or the ‘trans-actinide’ elements.
The long trek to the completion of row seven of periodic table, began in 1964. By then, heavy ion accelerators were getting more efficient, and able to accelerate ever heavier ions to strike targets in the search for superheavy elements. It was then that the Russian team bombarded element-94, plutonium, with element-10, neon. They were hoping that 94+10 = 104, and, sure enough, they detected fission products consistent with element 104 having formed briefly.
Naturally, Flerov’s team leapt to publish their finding and claim their prize on the table, proposing the name Kurchatovium, in honor of Igor Kurchatov, the leader of the Soviet nuclear bomb project. However, the name was never officially recognized by the IUPAC.
Meanwhile, the Americans in Berkeley, California, had a new tool at their disposal, the heavy ion linear accelerator, or HILAC, a new technology that allowed them launch ions as large as argon at targets. Using the HILAC, they successfully created element 104, five years later.
As with element 102, an argument ensued about who deserved rightful credit. Then, an IUPAC group convened in 1992 ruled that both the Russian and American researchers were somewhat justified in their claims, and declared element 104, rutherfordium.
The Russians vs. the Americans
The path to Element 105 was nearly identical. The Russians reported their first successful synthesis in 1968, but they did not propose a name in their initial publication. Naturally, this led the Berkeley group to believe that the Russians were uncertain of their results and encouraged them to forge ahead as well.
Thus, both the Russian and American researchers claimed success, and each proposed a different name. The Russians favored Danish physicist, Niels Bohr, as a namesake, while the Americans preferred Hahnium, in honor of the German nuclear chemist who had co-discovered nuclear fission, Otto Hahn.
But the IUPAC remained silent, and tables in the two countries diverged even more.
This article comes directly from content in the video series Understanding the Periodic Table. Watch it now, on Wondrium.
In the quest for element 106, the American group continued with the previous strategies that yielded elements 104 and 105. However, on the other side of the world, a young researcher at Dubna, named Yuri Oganessian, had another idea. Realizing that their lab might be reaching its technical limitations for using currently accepted techniques, and being quite literally ‘outgunned’ by the Super-HILAC at Berkeley, Oganessian suggested a whole new strategy—‘low-energy fusion’.
Oganessian’s idea was to fuse two large nuclei, one shot at the other, not with maximum energy like the Americans, but with just enough that it could barely overcome the coulomb force, repelling the two nuclei. Reducing the energy would reduce the likelihood of a productive collision, but it would also reduce the likelihood of smashing the target to bits when one happened.
He posited that in this scenario he just might be able to produce superheavy elements—a few atoms at a time—without the need for the astronomical projectile speeds that only the Super-HILAC had to offer.
The Trial Run
Oganessian turned to his periodic table recipe book, and chose, as a proof of concept, to try fusing element-18 (argon) with element-82 (lead) to produce element-100 (fermium). In spite of his colleagues’ doubts, it worked. Not only did it work, but it produced fermium-244, a previously undiscovered isotope!
He then switched up to using element 24 (chromium) for a low-energy collision with lead, and was able to successfully observe the fission products of element 106 at nearly the same time that Ghiorso’s group in Berkeley achieved their synthesis with the Super-HILAC.
Hence, the stage was set, once again, for a brawl over the rights to claim discovery and name element 106, or so it would seem. Surprisingly, it was agreed that neither lab would make an immediate recommendation for a name for element 106.
Once all of the results had been confirmed, the American team suggest the name Seaborgium, in honor of Glenn T. Seaborg, the godfather of heavy element discovery in the USA. There was surprisingly little pushback from the Russian team, and the name took hold.
With the co-discovery and provisional naming, of element 106, the transfermium wars had reached something of an armistice. Too tired to continue the battle, American and Russian labs had finally shown solidarity in their quest to reach the island of stability.
Common Questions about the Battle of the Transfermium Elements
In the periodic table, collectively, the 15 elements from the seventh row beyond lawrencium are referred to as the ‘superheavy’ elements.
An IUPAC group convened in 1992 ruled that both the Russian and American researchers were somewhat justified in their claims, and declared element 104, rutherfordium.
The American team suggested the name Seaborgium for element 106, in honor of Glenn T. Seaborg, the godfather of heavy element discovery in the USA.