Structure and decay chain of fermium isotopes using relativistic mean-field approach

• Main Authors: Das, Monalisa, Bhuyan, Mrutunjaya, Majekodunmi, Joshua T., Biswal, Nibedita, Panda, R. N.
• Format: Article
• Published: World Scientific Publishing 2022
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/41331/
• Institution: Universiti Malaya

In this paper, we have analyzed the ground state structural properties of fermium-isotopes in the mass range 221 <= A <= 279 within the relativistic mean-field with NL3* and Relativistic Hartree-Bogoliubov approach with DD-ME2 parameter sets. The bulk properties, such as binding energy, root mean-square charge radius, quadruple deformation parameter, chemical potentials, two-neutron separation energy and differential two- neutron separation energy, are estimated for the above Fm- isotopic chain. All the calculated observables are compared with finite range droplet model (FRDM) predictions and experimental data wherever available. The analysis predicts the existence of shell closure in the neutron-rich region of the isotopic chain at A = 225. The decay properties such as the alpha-decay energy and corresponding half-life for three decay chains i.e. Fm-243, Fm-245 and Fm-247 are studied. Six different empirical formulae, namely; Viola-Seaborg, Royer, modified B. Alex Brown, Parkhomenko-Sobiczewski, Universal decay law and modified universal decay law are employed to ascertain the numerical dependency of the half-life for each decay energy. A comparative study of Q-values and half-lives for these decay chains gives a good signature of the calculated results. The half-life calculations of three decay chains suggest that Pu-231, Pu-233, Pu-235 are shell closure nuclei having , maximum half-lives, whereas Fm-243, Fm-245 and Fm-247 are shell stabilized with lower half-lives.