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Isotopes of ununennium
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Isotopes of ununennium
Ununennium (119Uue) has not yet been synthesised, so there is no experimental data and a standard atomic weight cannot be given. Like all synthetic elements, it would have no stable isotopes.
No isotopes of ununennium are known.
The below table contains various combinations of targets and projectiles that could be used to form compound nuclei with Z = 119.
Following the claimed synthesis of 293Og in 1999 at the Lawrence Berkeley National Laboratory from 208Pb and 86Kr, the analogous reactions 209Bi + 86Kr and 208Pb + 87Rb were proposed for the synthesis of element 119 and its then-unknown alpha decay daughters, elements 117, 115, and 113. The retraction of these results in 2001 and more recent calculations on the cross sections for "cold" fusion reactions cast doubt on this possibility; for example, a maximum yield of 2 fb is predicted for the production of 294Uue in the former reaction. Radioactive ion beams may provide an alternative method utilizing a lead or bismuth target, and may enable the production of more neutron-rich isotopes should they become available at required intensities.
There are indications that the team at the Joint Institute for Nuclear Research (JINR) in Russia plans to try this reaction in the future. The product of the 3n channel would be 294Uue; its expected granddaughter 286Mc was synthesised in a preparatory experiment at the JINR in 2021, using the reaction 243Am(48Ca,5n)286Mc.
The team at the Heavy Ion Research Facility in Lanzhou (HIRFL), which is operated by the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences, also plans to try the 243Am+54Cr reaction.
The team at RIKEN in Wakō, Japan began bombarding curium-248 targets with a vanadium-51 beam in January 2018 to search for element 119. Curium was chosen as a target, rather than heavier berkelium or californium, as these heavier targets are difficult to prepare. The reduced asymmetry of the reaction is expected to approximately halve the cross section, requiring a sensitivity "on the order of at least 30 fb". The 248Cm targets were provided by Oak Ridge National Laboratory. RIKEN developed a high-intensity vanadium beam. The experiment began at a cyclotron while RIKEN upgraded its linear accelerators; the upgrade was completed in 2020. Bombardment may be continued with both machines until the first event is observed; the experiment is currently running intermittently for at least 100 days per year. The RIKEN team's efforts are being financed by the Emperor of Japan.
The produced isotopes of ununennium are expected to undergo two alpha decays to known isotopes of moscovium (288Mc and 287Mc respectively), which would anchor them to a known sequence of five further alpha decays and corroborate their production. In 2022, the optimal reaction energy for synthesis of ununennium in this reaction was experimentally estimated as 234.8±1.8 MeV at RIKEN. The cross section is probably below 10 fb.
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Isotopes of ununennium
Ununennium (119Uue) has not yet been synthesised, so there is no experimental data and a standard atomic weight cannot be given. Like all synthetic elements, it would have no stable isotopes.
No isotopes of ununennium are known.
The below table contains various combinations of targets and projectiles that could be used to form compound nuclei with Z = 119.
Following the claimed synthesis of 293Og in 1999 at the Lawrence Berkeley National Laboratory from 208Pb and 86Kr, the analogous reactions 209Bi + 86Kr and 208Pb + 87Rb were proposed for the synthesis of element 119 and its then-unknown alpha decay daughters, elements 117, 115, and 113. The retraction of these results in 2001 and more recent calculations on the cross sections for "cold" fusion reactions cast doubt on this possibility; for example, a maximum yield of 2 fb is predicted for the production of 294Uue in the former reaction. Radioactive ion beams may provide an alternative method utilizing a lead or bismuth target, and may enable the production of more neutron-rich isotopes should they become available at required intensities.
There are indications that the team at the Joint Institute for Nuclear Research (JINR) in Russia plans to try this reaction in the future. The product of the 3n channel would be 294Uue; its expected granddaughter 286Mc was synthesised in a preparatory experiment at the JINR in 2021, using the reaction 243Am(48Ca,5n)286Mc.
The team at the Heavy Ion Research Facility in Lanzhou (HIRFL), which is operated by the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences, also plans to try the 243Am+54Cr reaction.
The team at RIKEN in Wakō, Japan began bombarding curium-248 targets with a vanadium-51 beam in January 2018 to search for element 119. Curium was chosen as a target, rather than heavier berkelium or californium, as these heavier targets are difficult to prepare. The reduced asymmetry of the reaction is expected to approximately halve the cross section, requiring a sensitivity "on the order of at least 30 fb". The 248Cm targets were provided by Oak Ridge National Laboratory. RIKEN developed a high-intensity vanadium beam. The experiment began at a cyclotron while RIKEN upgraded its linear accelerators; the upgrade was completed in 2020. Bombardment may be continued with both machines until the first event is observed; the experiment is currently running intermittently for at least 100 days per year. The RIKEN team's efforts are being financed by the Emperor of Japan.
The produced isotopes of ununennium are expected to undergo two alpha decays to known isotopes of moscovium (288Mc and 287Mc respectively), which would anchor them to a known sequence of five further alpha decays and corroborate their production. In 2022, the optimal reaction energy for synthesis of ununennium in this reaction was experimentally estimated as 234.8±1.8 MeV at RIKEN. The cross section is probably below 10 fb.