Electron–Ion-Coincidence Measurements for K-Shell Excited Free Krypton Clusters

抄録

The decay processes of inner-core excited krypton atom and free krypton clusters up to ⟨N⟩=1640, ⟨N⟩ being the average cluster size, have been studied by means of electron ion coincidence (EICO) measurements utilizing hard X-ray. Unlike the soft X-ray absorption measurements, highly charged daughter ions are observed. With increasing cluster size, the relative abundance of the multiply charged ions decreases and that of singly charged dimer or trimer ions increases. The results may be interpreted if one takes site-dependent decay processes into account: when the core hole is generated on the cluster surface, the proliferated holes due to the vacancy cascade are strongly localized within the X-ray absorbing atom, while the charges are migrated to surrounding atoms when the X-ray absorption occurs inside the cluster.