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But as they pushed back the boundaries of the known universe, they began to worry that their work would eventually stall. The Chart of the Nuclides seemed to have a brake built into it; the heavier the element "discovered" or -- perhaps more accurately -- created by the LBNL team, the less stable the nucleus, until the heaviest elements existed for mere wisps of time before falling apart. While the longest-lived isotope neptunium has a half-life of 2.14 million years, the half-life of the longest-lived isotope of meitnerium, which was discovered in 1982 and is the last element to be named, is just 70 milliseconds. Even if scientists could create heavier elements in a laboratory setting, what good would come of making something that vanished as soon as they saw it? Starting in the '70s, a team of German scientists overtook LBNL researchers as the leaders in discovering new elements, but they also worried that their work had hit a dead end. Researchers around the world were beginning to admit that perhaps there was a limit to the universe of atomic structure.
Then about seven years ago, this once revolutionary but now faded field got a new lease on life. Since the '60s, a theoretician at the Berkeley lab named Wladyslaw Swiatecki had been arguing for the existence of "superheavy elements," whose nuclear structure would be far more stable than the heaviest "transuranic" elements discovered so far. (Transuranic elements are those that are heavier than uranium and virtually never occur outside the laboratory.) Swiatecki's theories proposed that well beyond the current boundaries of the Periodic Table there exist "islands of stability," elements whose half-lives could be measured not in milliseconds, but years or centuries. All we had to do was leapfrog over this "sea of transuranic instability," Swiatecki claimed, and we would stumble upon entire species and genera of new matter, whose properties and attributes we could only guess at -- and whose applications as fuel or terrifying new weapons were unimaginable.
In 1997, the prospect of landing on these islands of stability never seemed brighter. Armed with a new crop of fusion models, state-of-the-art detection equipment, and an infusion of young, enthusiastic scientists, research teams in Germany, Russia, and Berkeley began a little-noticed but fiercely competitive race to discover elements 114 and above, which would theoretically land us on the beach of Swiatecki's island. Lawrence Berkeley Lab, Germany's Institute for Heavy Ion Research (GSI), and the Joint Institute for Nuclear Research in Dubna, Russia, all began smashing particles together in a race to ultimately create an isotope of element 126, the theoretical peak of superheavy stability and the apogee of a new, glorious swath of undiscovered elemental territory.
In the spring of 1999, LBNL researchers thought they had come closer to this goal than ever. When they fired a beam of krypton particles at a lead target inside the lab's famed 88-inch cyclotron, the subsequent energy readings led them to believe that, for less than one millisecond, element 118 had come into existence before decaying into element 116, 114, and down the chain until reaching the relatively stable state of seaborgium. Berkeley came to believe that, for one brief instant, they had come within reach of an entire virgin continent of matter, a clan of ions and nuclides and probability clouds that to their knowledge had never before existed in the universe.
But they were wrong. It took two years of additional research, but finally Ken Gregorich's team was forced to admit that somehow, someone had misread the data, and no one had caught the mistake. Up in the Berkeley Hills, amid the tangled eucalyptus groves and particle accelerators, the nuclear physicists of Lawrence Berkeley Laboratory had pushed back the terra incognita of the universe, only to have it spill around their ankles once more.
It's fair to say that sixty years ago, Albert Ghiorso stumbled into what would become a stellar career as a nuclear physicist. He didn't rise through the ranks of academia; indeed, his credentials consisted of nothing more than the Bachelor's of Science degree in electrical engineering he received from UC Berkeley in 1937. He first met Seaborg while working for a company that built Geiger counters. "In the spring of 1942, I got a letter from Albert asking whether I would be willing to recommend him for some kind of job in the Navy," Seaborg wrote in The Transuranium People, the official LBNL account of the early years of heavy element research. "Actually, I didn't know Al very well. This is one of those cases where our wives took over. My wife, Helen, who had worked ... as Ernest Lawrence's secretary, was a very good friend of Al's wife, Wilma, who was working here in the laboratory.... When the letter came, Helen told me, 'You hire this guy.' ... He wasn't easy to convince; he was afraid that all I had in mind for him was to continue building Geiger counters."
Seaborg had already achieved some renown as part of the team that discovered plutonium, but he was soon onto bigger and better things. By 1944, Ghiorso was working side by side with Seaborg on his latest project: the creation of elements 95 and 96 -- which would eventually be named americium and curium -- at the Metallurgical lab in Chicago. The tools for colliding elements and measuring the results were hopelessly crude by modern standards, and Seaborg was further distracted by his work extracting and purifying plutonium for the Manhattan Project, but eventually, he was able to set up a series of experiments at the cyclotrons at the University of Washington and the UC Berkeley Radiation Lab. Seaborg's team bombarded an isotope of plutonium (then the heaviest element known to man) with deuterons, or hydrogen nuclei with two neutrons. Over the next few months, researchers repeated the experiments, hoping to find the telltale signs that the two particles had fused into element 95, but found nothing. On July 8, 1945 Berkeley researchers tried bombarding plutonium with a helium ion instead, and over the course of the next few months were finally able to determine that the experiments had produced elements 95 and 96.
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