Selecting cold 2n transfer in ¹⁶²Dy(¹¹⁶Sn,¹¹⁸Sn)¹⁶⁰Dy

Abstract.

Cold 2n transfer has been studied using the reaction ¹⁶²Dy(¹¹⁶Sn,¹¹⁸Sn)¹⁶⁰Dy at energies in the vicinity of the Coulomb barrier. The experiment was performed at the Heidelberg-Darmstadt Crystal Ball spectrometer which was extended by 6 Compton suppressed Ge-detectors. It is demonstrated, that the direct population of intrinsically cold states in the deformed ¹⁶⁰Dy transfer product can be selected by identifying and suppressing excitations to states above the yrast line using the Crystal Ball. The probability for populating yrast states in the deformed ¹⁶⁰Dy nuclei in a 2n transfer reaction increases from 7% at grazing collisions up to ≈ 50% at large impact parameters, while the probability for populating the ground state in the spherical 2n transfer product ¹¹⁸Sn stays about constant at ≈ 45% for all measured impact parameters.