Hyperfine interactions of light nuclei recoil-implanted into iron

Abstract

The perturbed integral angular distribution technique has been used to study hyperfine interactions of light nuclei recoil-implanted into iron. Heavy- ion-induced fusion-evaporation reactions populated the excited states of $sup 37$Ar, $sup 39$,$sup 40$,$sup 41$K, and $sup 41$Ca, whose deexciting $gamma$ rays were observed in a Ge(Li) detector. In all cases the measured shifts of the angular distributions were found much smaller than the ones calculated using the known values of g factors, lifetimes, and strengths of the internal hyperfine fields. This can be explained under the assumption that only a fraction of the nuclei feel the full internal magnetic field, while the rest of them do not feel any magnetic interaction at all. Different fractions obtained for $sup 40$K and $sup 41$K suggest a migration process on a ns time scale of the implanted ions in the lattice. (AIP)