Speaker
Description
We have carried out measurements, using Miniball, of the $\gamma$-ray de-excitation of $^{222,228}$Ra and $^{222,224,226}$Rn nuclei Coulomb-excited by bombarding $^{60}$Ni and $^{120}$Sn targets. The beams of radioactive ions, having energies of between 4.25 and 5.08 MeV.A, were provided by HIE-ISOLDE. The purpose of these measurements is to determine the intrinsic quadrupole and octupole moments in these nuclei and look for other cases of permanent octupole deformation to those of $^{224,226}$Ra already reported$^{1,2}$. One aim of this experiment is to determine the level schemes of $^{224,226}$Rn in order to characterise these isotopes as octupole vibrational or octupole deformed. We present here the preliminary results of this analysis which suggests that radon even-even nuclei in this mass region are all octupole vibrational. The implications for EDM searches in radon atoms will be discussed.
$^1$ Gaffney L P et al. 2013 Nature $\bf 497$ 199
$^2$ Wollersheim H J et al. 1993 Nuclear Physics A $\bf 556$ 261
