Design of a self shield type slow positron source using an isotope

We have been constructing an electrostatically transported slow positron beam line for depth profiling of ion-induced defects and others. If a usual shielding was applied, the size of the equipment would become too large in order to reduce γ-rays from a positron-emitting isotope which reach the sample. We performed design calculations for a structure of a compact and efficient slow positron source. (author)