Synthesis of new superheavy nuclei in reactions of 50Ti, 51V, and 54Cr beams with actinide targets

Tomasz Cap (National Centre for Nuclear Research, Warsaw, Poland)

The heaviest known element, oganesson, with an atomic number Z=118, was synthesized in a fusion reaction of a 48Ca projectile with a 249Cf target. Californium is currently the heaviest actinide that can be produced in the quantity necessary for superheavy nuclei synthesis reactions. For this reason, the synthesis of new elements must rely on the use of projectiles made from elements heavier than calcium. Currently, various laboratories around the world are developing or have already developed beams of 50Ti, 51V, and 54Cr. These beams can also be used in reactions with lighter actinides to synthesize new isotopes of known elements.

The results and future prospects of selected experiments, particularly the latest efforts aimed at producing elements with atomic numbers 119 and 120, will be presented. Reactions using 50Ti, 51V, and 54Cr beams, which are considered to have the highest probability of success, will be discussed in detail. Calculations of cross sections, performed within the framework of the Fusion-by-Diffusion (FBD) model, will be presented. The FBD model considers the production cross section as the product of three factors: the cross section for the projectile to overcome the entrance channel barrier (capture cross section), the probability that the resulting system fuses and reaches the compound nucleus configuration, and the probability that the excited compound nucleus survives fission during de-excitation.