Investigation on the structure properties of thorium nuclei spanned between the drip-lines and the prediction of shell closure

The structure properties of nuclei that reside significantly away from the line of β -stability are currently the focus of both theoretical and experimental studies. Various theoretical methodologies are being employed to explore these nuclear structure properties. In our research, we have calculated several structure properties, including binding energy, charge radii, root mean square (rms) radii and their isotopic variations, two-neutron separation energy, shell gap, chemical potential, quadrupole deformation, density distribution, and single-particle energy for thorium nuclei, which are found both on and off the line of β -stability. Thorium nuclei are particularly intriguing due to their diverse practical applications, including their role in thorium-based nuclear reactors and their involvement at various stages of nucleosynthesis. This study helps us gain insight into how nuclear properties change with the number of neutrons and enables us to predict shell closures and nuclear stability. The estimated values were compared with available experimental and theoretical data and are found to be in good agreement. The departure from a linear trend observed around specific neutron numbers, specifically N = 126, 138, and 184, in graphs depicting various properties against neutron number and single-particle energy gap, can be attributed to the concept of neutron magic numbers. Among these, N = 126 and N = 184 are considered neutron magic numbers, while N = 138 is regarded as a semi-magic number.