Spectroscopic Isotope Shift and Nuclear Deformations

With a method developed in a previous paper the isotope shift due to a difference in nuclear deformation of two isotopes is calculated, making certain simplifying assumptions about the nuclear charge distribution. If both isotopes have a spectroscopic quadrupole moment these may then be used to make an estimate of the deformations. It is found that the difference between the intrinsic and spectroscopic quadrupole moments is quite crucial and that when this is taken into account the anomalously large isotope shift of Eu is satisfactorily explained with the experimentally determined quadrupole moments. Using available data on quadrupole and magnetic moments, a tentative examination of other isotope shift data in terms of the deformation dependent isotope shift indicates that this may perhaps explain the large observed variations.