2012/10/15 by Walter Greiner · 1 citation
Physics and Astronomy · Medicine · #Nuclear physics research studies #Astronomical and nuclear sciences #Radiopharmaceutical Chemistry and Applications #Superheavy Elements #Element (criminal law) #Heavy element #Stability (learning theory) #Physics #Nuclear physics #Materials science #Computer science #Astrophysics
paper · pdf · doi:10.1103/physics.5.115
openalex publication_date 2012/10/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Two years after the discovery of element 117, we undertook a second campaign using the 249 Bk 48 Ca reaction for further investigations of the production and decay properties of the isotopes of element 117 on a larger number of events. The experiments were started in the end of April 2012 and are still under way. This Letter presents the results obtained in 1200 hours of an experimental run with the beam dose of 48 Ca of about 1:5 10 19 particles. The 249 Bk target was irradiated at two energies of 48 Ca that correspond to the maximum probability of the reaction channels with evaporation of three and four neutrons from the excited 297 117. In this experiment, two decay chains of 294 117 (3n) and five decay chains of 293 117 (4n) were detected. In the course of the long-term work, 249 Cf-the product of decay of 249 Bk (330 d)-is being accumulated in the target. Consequently, in the present experiment, we also detected a single decay of the known isotope 294 118 that was produced during 2002-2005 in the reaction 249 Cf 48 Ca; 3n 294 118. The obtained results are compared with the data from previous experiments. The experiments are carried out in the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, using the heavyion cyclotron U400.