Calculations of Branching Ratios for Radiative-Capture, One-Proton, and Two-Neutron Channels in the Fusion Reaction $^{209}$Bi+$^{70}$Zn

TL;DR

This paper calculates the likelihood of various nuclear reaction channels in the fusion of $^{70}$Zn and $^{209}$Bi, focusing on the probabilities of proton, radiative, and two-neutron emissions, to understand element Z=113 production.

Contribution

It provides the first estimates of upper bounds for non-one-neutron emission channels in the fusion reaction leading to element Z=113, considering parameter variations.

Findings

Two-neutron emission channel has the highest probability among non-one-neutron channels.

Upper bounds for the two-neutron channel are less than 7.9% under realistic conditions.

Proton and radiative channels have significantly lower probabilities, around 2.4%.

Abstract

We discuss the possibility of the non-one-neutron emission channels in the cold fusion reaction $^{70}$Zn + $^{209}$Bi to produce the element Z=113. For this purpose, we calculate the evaporation-residue cross sections of one-proton, radiative-capture, and two-neutron emissions relative to the one-neutron emission in the reaction $^{70}$Zn + $^{209}$Bi. To estimate the upper bounds of those quantities, we vary model parameters in the calculations, such as the level-density parameter and the height of the fission barrier. We conclude that the highest possibility is for the 2n reaction channel, and its upper bounds are 2.4$%$ and at most less than 7.9% with unrealistic parameter values, under the actual experimental conditions of [J. Phys. Soc. Jpn. {\bf 73} (2004) 2593].