Spectroscopy of actinide nuclei
Dr Sankha S Hota
Nuclear Physics Department
Experimental studies of the excitations of the heaviest elements around Z ~ 100, A ~ 250, whose unexpected stability is attributed to shell effects, provide important checks of theoretical model predictions, in particular for the location of the next higher spherical shell gaps. While fusion-evaporation reactions have led the way for the spectroscopy of the heaviest elements with Z ≥ 100, complementary information gathered from Z < 100 nuclei via deep-inelastic and transfer reactions provides a more comprehensive template for understanding both collective and single-particle behaviour in this region, where proton and neutron orbitals in the highest oscillator shells are active participants. In our quest for understanding the structures of transuranium elements, we report here on new spectroscopic observations in the relatively neutron-rich nuclei of Pu, Cm, and Cf isotopes. High-spin states in these nuclei were populated via deep-inelastic and transfer reactions using Pb, Bi beams incident on radioactive targets. Prompt γ rays were detected with the Gammasphere array. The complete alignment systematics for N = 150, 151, and 152 isotopes and isotones show interesting variations. The talk will focus on the extended systematics of this region and available theoretical predictions for the neutron-rich, transplutonium N ≥ 150 nuclei.