Systematics of fusion probability in "hot" fusion reactions

TL;DR

This paper systematically investigates the fusion probability in hot fusion reactions for super-heavy element synthesis, proposing an analytical model based on the quasi-fission barrier that aligns well with experimental data.

Contribution

It introduces a new analytical expression for fusion probability using the quasi-fission barrier height from Skyrme energy-density functional, improving predictions of evaporation residual cross sections.

Findings

The model reproduces measured evaporation residual cross sections effectively.

Predicted cross sections for element 119 synthesis are in the 10-150 fb range.

Cross sections for element 120 synthesis are extremely low, below current experimental capabilities.

Abstract

The fusion probability in "hot" fusion reactions leading to the synthesis of super-heavy nuclei is investigated systematically. The quasi-fission barrier influences the formation of the super-heavy nucleus around the "island of stability" in addition to the shell correction. Based on the quasi-fission barrier height obtained with the Skyrme energy-density functional, we propose an analytical expression for the description of the fusion probability, with which the measured evaporation residual cross sections can be reproduced acceptably well. Simultaneously, some special fusion reactions for synthesizing new elements 119 and 120 are studied. The predicted evaporation residual cross sections for 50Ti+249Bk are about 10-150fb at energies around the entrance-channel Coulomb barrier. For the fusion reactions synthesizing element 120 with projectiles 54Cr and 58Fe, the cross sections fall to a few femtobarns which seems beyond the limit of the available facilities.