Backbending of ¹⁶²Dy using Nilsson deformed model

Deformed shell model was proposed by Nilsson with phenomenological model potential called modified oscillator potential, in order to investigate the effect of deformation on single particle energy levels and to explain shell structure. The deformed nuclei can show pronounced gaps in the single particle levels much analogous to spherical nuclei. Shell closure or magicity leads to large gaps in the single particle levels, which reveals increased stability of a nucleus. Shell closure is also encountered in deformed nucleus at specific nucleon numbers. Among the approaches to solve nuclear many body problem, there were three potentials such as Nilsson potential, Woods-Saxon potential and Yukawa mean field potential which are used extensively. In Nilsson potential the spin-orbit term is incorporated with a constant κ and ℓ² term, to lower the energy of the single-particle states closer to the nuclear surface in order to correct for the steep rise in the harmonic-oscillator potential and is parametrised by the notation μ