Formation of transfermium elements in reactions with $^{208}$Pb

TL;DR

This paper models the fusion process for creating transfermium elements using a Langevin framework, revealing the dynamics of energy dissipation and shape evolution, and successfully matching experimental data.

Contribution

It introduces a novel Langevin-based simulation approach for transfermium formation, incorporating a five-dimensional potential-energy landscape.

Findings

Good agreement with experimental data on formation probabilities

Identification of energy dissipation as key in early fusion dynamics

Shape evolution as a diffusive process in the model

Abstract

Within the Langevin framework, we investigate the dynamics of the fusion process for production of transfermium elements in reactions of $^{48}$Ca, $^{50}$Ti, $^{54}$Cr, and $^{58}$Fe with $^{208}$Pb. After the reacting nuclei have made contact, the early dynamical stage is dominated by the dissipation of the initial radial kinetic energy, while the subsequent shape evolution is diffusive. The probability for surmounting the inner barrier and forming a compound system is obtained by simulating the evolution as a Metropolis random walk in a five-dimensional potential-energy landscape. Good agreement with the available data is obtained, especially for the maximal formation probability.