Application of improved exponential model to some nuclei in the regionA= 100–192

Abstract

A modified version of the exponential model with paring attenuation is used to describe successfully the backbending of the moment of inertia, in even–even nuclei, in the region A = 100–192. The model fits remarkably well to the experimental observation with a few parameters.

Nuclear structure study of some actinide nuclei

“…The present work suggests that the modified version of the exponential model predictions gives a fairly accurate description of the backbending in actinide nuclei, in support to our previous calculations [17]. Also, the present interpretation goes parallel with the idea that the behaviour of the i 13/2 proton pair and the J 15/2 neutron pair at high spins play a decisive role for the appearance of backbending phenomena in this mass region.…”

“…They used I c = 85h in their calculations since many experimentally observed superdeformed bands near A = 190 persist to I ∼ 50h [23] and the pairing correlation in that region is still strong even at very high rotational frequency hω = 0.5 MeV [24]. Accordingly, to have suitable I c values representing both the variation of the moment of inertia and the pairing correlation disappearance in the majority of slightly and deformed even-even nuclei, a recent modification of the exponential model with paining attenuation (equation 3) has been undertaken by letting ν to be a free parameter in the following expression [17]:…”

“…The main purpose of the present work is to investigate Th, U and Pu even-even nuclei in a phenomenological way in the framework of a three-parameter formula [17] based on the exponential model with pairing attenuation [18]. It is hoped by such work to have a good description of the backbending regions besides those of the low-lying states of some actinide nuclei.…”

Comparative Phenomenological Description of Even-Even Isotopes at Mass Region A ≈ 70

“…The excitation energy E(I) of the yrast bands, the moment of inertia and the squared rotational frequency ω 2 are deduced by using the well-known relation [28]:…”

“…Additionally, an improved version of the exponential model with pairing attenuation has been also applied in the present work [28]. It is hoped by such work to have a good description of the backbending regions besides those of low-lying states.…”