Theories had been launched way back to the 1960s in regards to the potential existence of superheavy parts. Their most long-lived nuclei might give rise to a so-called “island of stability” far past the factor uranium. However, a brand new examine, led by nuclear physicists at Lund University, exhibits {that a} 50-year-old nuclear physics manifesto should now be revised.
The heaviest factor present in nature is uranium, with a nucleus containing 92 protons and 146 neutrons. The nuclei of heavier parts turn out to be increasingly more unstable as a result of elevated variety of positively charged protons. They subsequently decay sooner and sooner, normally inside a fraction of a second.
A “magical” mixture of protons and neutrons might nevertheless result in parts with quickly growing lifetimes. Just such a “magical” variety of protons has lengthy been predicted for the factor flerovium, which has the atomic quantity 114 within the periodic desk. In the late 1960s a concept was launched by Lund physicist Sven-Gösta Nilsson, amongst others, that such an island of stability ought to exist across the then nonetheless undiscovered factor 114.
“This is something of a Holy Grail in nuclear physics. Many dream of discovering something as exotic as a long-lived, or even stable, superheavy element,” says Anton Såmark-Roth, doctoral scholar of nuclear physics at Lund University.
Inspired by Nilsson’s theories, the researchers have studied the factor flerovium intimately and made ground-breaking discoveries. The experiment was performed by a world analysis workforce led by Dirk Rudolph, a professor at Lund University.
Within the framework of the analysis program FAIR Phase-Zero on the particle accelerator facility GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany, as much as 6×1018 (6,000,000,000,000,000,000) calcium-48 atomic nuclei had been accelerated to 10 p.c of the velocity of sunshine. They bombarded a skinny movie of uncommon plutonium-244 and, by atomic nuclear fusion, flerovium might be created, one atom at a time. In the 18-day-long experiment, the research team then registered radioactive decay of some tens of flerovium nuclei in a detection device specially developed in Lund.
Through the exact analysis of decay fragments and the periods within which they were released, the team could identify new decay branches of flerovium. It was shown that these could not be reconciled with the element’s previously predicted “magical” properties.
“We were very pleased that all the technology surrounding our experimental set-up worked as it should when the experiment started. Above all, being able to follow the decay of several flerovium nuclei from the control room in real time was very exciting,” says Daniel Cox, postdoc in nuclear physics at Lund University.
The new results, published in the research journal Physical Review Letters, will be of considerable use to science. Instead of looking for the island of stability around the element 114, the research world can focus on other as yet undiscovered elements.
“It was a demanding but, of course, very successful experiment. Now we know, we can move on from element 114 and instead look around element 120, which has not been discovered yet. Now the voyage to the island of stability will take a new course,” concludes Anton Såmark-Roth.
Reference: “Spectroscopy along Flerovium Decay Chains: Discovery of 280Ds and an Excited State in 282Cn” by A. Såmark-Roth et al., 22 January 2021, Physical Review Letters.
DOI: 10.1103/PhysRevLett.126.032503
