![]() Studying them, however, tests scientists’ understanding of the atomic nucleus. Most superheavy elements’ very limited lifetimes prevents their use in real-world applications. ‘This may be a path to access isotopes that are not reachable by fusion reactions.’ Pushing the boundaries ‘In some cases that might lead to a product that happens to have, for example, 120 protons,’ Düllmann says. But the colliding nuclei can exchange protons and neutrons when they collide. If you fired uranium at a uranium target the nuclei will never fuse, explains GSI researcher Christoph Düllmann. One idea to overcome the limitations of current heavy element synthesis techniques is to induce nuclear transfer reactions. Eric Scerri, a chemistry historian at the University of California, Los Angeles, US, agrees: ‘Fifteen years ago it was inconceivable that anyone would ever get as far as we got.’ The hunt for new elements, he adds, has been and will be driving technology development. ![]() ‘Within one generation’s lifetime we will probably reach element 124,’ speculates Rykaczewski. The Superheavy Element Factory that is being built at Dubna will have improved detection capabilities and be able to generate beams with significantly higher intensities, but ‘additional breakthroughs will be needed to continue beyond element 120’, says Roberto. Synthesising the 20mg of berkelium used to produce element 117 took more than two years. You could also make the target much larger and spread the projectile beam over its larger area,’ he adds – but making these actinide targets is not easy. But ‘hitting the target with an even higher number of projectiles would actually burn the target’, explains ORNL physicist Krzysztof Rykaczewski. It took researchers more than two years to produce a tiny amount of berkelium used to make element 117Ĭurrent accelerators hit the target with about 10 12 projectiles every second. An apparently simple solution would be to just fire more and heavier projectiles at the target. Targeting new technologiesįiring calcium projectiles at a very heavy actinide target worked well for producing elements 114 to 118, but for even heavier elements the likelihood of creating a new element this way declines. In order for scientists to be confident that they really have made a new element, they must follow the new element’s signature decay chains, explains James Roberto, associate laboratory director at Oak Ridge National Laboratory (ORNL) in the US. However, both teams only observed an assortment of lighter nuclei and particles. As early as 2007, researchers at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and the Helmholtz Centre for Heavy Ion Research (GSI) in Darmstadt, Germany, tried to synthesise unbinilium or element 120 by bombarding plutonium with iron and uranium with nickel, respectively. To create a new element, a heavy element target is bombarded with highly accelerated lighter element projectiles. ![]() But while no group has yet claimed to have created an element that belongs on the eighth row of the periodic table it isn’t from lack of trying. This is what makes the absence of any claim on the creation of element 119 or beyond surprising. Typically the claim of the first synthesis of a new superheavy element comes many years before enough evidence is gathered to get the nod of approval from Iupac. Each time a group claims to have synthesised a new element the International Union of Pure and Applied Chemistry (Iupac) must weigh the evidence presented. Since Edwin McMillan and Philip Abelson synthesised the first transuranium element neptunium in 1940, a steady stream of new elements has filled the lower rows of the periodic table. Particle accelerators create new elements by bombarding a heavy element target with highly accelerated lighter
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