Suggested Effective Moment of Inertia Model, Examination of Identical Bands and ΔΙ = 2 Energy Staggering Applied to Some Actinide Nuclei

A collective rotational model contains five parameters is proposed assuming that the effective moment of inertia depends on the spin proposition. The model is applied to the ground state bands of nine normal deformed even-even actinide nuclei, namely 230, 232Th, $$^{{{\text{234}}{\text{,236}}{\text{,238}}}}{\text{U}}$$ , $$^{{{\text{236}}{\text{,238}}{\text{,240}}}}{\text{Pu}}$$ , and $$^{{{\text{246}}}}{\text{Cm}}$$ . The model parameters are determined by using a computer simulated fitting search program in order to minimize the relative root mean square deviation between experimental and calculated excitation energies. The excellent agreement between experimental and calculated energies presents a good support of our proposed model. It is found that the transition energies of the two pairs ( $$^{{{\text{236}}}}{\text{U}}$$ , $$^{{{\text{238}}}}{\text{U}}$$ ) ,and ( $$^{{{\text{240}}}}{\text{Pu}}{{{\text{,}}}^{{{\text{246}}}}}{\text{Cm}}$$ ) are identical within 3 keV up to high spin, which indicate that the phenomenon of identical bands is not restricted to superdeformed bands.The presence of $$\Delta I = 2$$ staggering in transition energies are investigated by calculating a staggering function represents the fourth order derivative of the gamma ray transition energies ( the five point formula of Cederwall et al.). Significant staggering are observed for our selected actinide deformed nuclei.