Hyperfine quenching of resonances in dielectronic recombination of zinc-like Pt48+

Dielectronic recombination (DR) of zinc-like platinum ions was measured at the Heidelberg heavy-ion storage-ring TSR. Pronounced differences were observed in the DR resonance structure of the isotopes 194Pt and 198Pt on the one hand and of the isotope 195Pt on the other hand. The differences are ascribed to the presence of a metastable 4s4p 3P0 component in the 194Pt48+ and 198Pt48+ ion beams. The hyperfine quenching of this component in the 195Pt48+ ion beam manifests itself by 'missing' DR resonances associated with strong excitations of ions in the metastable 4s4p 3P0 state.