Scientists at the Laboratory of Nuclear Reactions at JINR, in collaboration with colleagues from scientific centres in Russia, China, and Kazakhstan, studied the properties of the radioactive decay of the new ²²⁷Pu (plutonium-227) nucleus and its daughter products. For the first time, the obtained data of the plutonium nuclei half-lives are in good agreement with theoretical predictions and existing taxonomies.

Superheavy Element Factory

The research was carried out at FLNR at JINR using the GRAND Gas-Filled Separator for products of complete fusion reactions at the Superheavy Element Factory. It is used for experiments on beams of multiple charged ⁴⁸Ca ions with a record intensity reaching 10 µA · particles. To register recoil nuclei and their daughter products, scientists used the GABRIELA Detector Array, developed for precision α, β, γ correlation spectroscopy of short-lived nuclei obtained in reactions with heavy ions.

Studying the properties of nuclei located far from the β-stability line makes it possible to determine how neutron or proton excess in the nucleus affects the radioactive decay properties. In reactions of complete fusion of ²⁶Mg ions with target nuclei of ^{204, 206}Pb in channels with evaporation of several neutrons taking place, the scientists studied the radioactive decay properties of the lightest plutonium isotopes up to N = 132. The data obtained were compared with theoretical estimates (Q_α) and the half-life systematics.

The new isotope ²²⁷Pu with E_α = (8156 ± 26) keV has a half-life of 2,2−0,3+0,5 s and the probability of electron capture b_EC = 0,23 ± 0,1. A correlating event was recorded in the ²⁶Mg + ²⁰⁴Pb reaction, which can be attributed to the α-decay of the new isotope ²²⁶Pu (E_α = (8754 ± 24) keV) with an estimated lower half-life limit of 1 ms. The scientists concluded that the isotope ²²⁷Pu demonstrates an increase in α-decay relative survival, characteristic of even-odd nuclei.

Read more about the research titled “Properties of radioactive decay of the new nucleus 227Pu” in preprint P7-2024-50 issued by the JINR Publishing Department. Among the authors are employees of the Joint Institute for Nuclear Research: Alena Kuznetsova, Alexandr Svirikhin, Andrey Isaev, Maksim Bychkov, Vladislav Danilkin, Haleshappa Devaraja, Nikolay Zamyatin, Igor Izosimov, Oleg Malyshev, Roman Mukhin, Andrey Popeko, Yuri Popov, Vladimir Rachkov, Bekzat Sailaubekov, Evgeny Sokol, Mereigul Tezekbayeva, Irina Ulanova, Victor Chepigin, Maxim Chelnokov, and Alexander Eremin.