Interaction sizes of the even neodymium isotopes from elasticαscattering

Differential cross sections for $\alpha$ particles elastically scattered from ${}_{}{}^{142,144,146,148,150}{}_{}{}^{}\mathrm{Nd}$ have been measured at six angles over the energy region 11-19 MeV. The cross sections were analyzed using the optical model, the incoming-wave boundary condition model, and the coupled-channels model. The radius at which the real nuclear potential is 2% of the Coulomb potential was found to be effectively independent of the ambiguities in the optical potential. In the coupled-channels analysis, the radius at which the spherically averaged real nuclear potential is 2% of the spherically averaged Coulomb potential is almost identical, for a given nucleus, to the corresponding quantity determined using the spherical optical model. The absolute increase in the "2% radius" over the neodymium isotopes is about 2 times larger than the increase in the charge distribution as observed in muonicatom and electron-scattering studies.