Detection of the metastable chain hydrocarbon anions by an electrostatic ion storage ring

Chain hydrocarbon anions, C4H- and C6H- extracted from a cesium sputter ion source, were stored in an electrostatic ion storage ring. The neutral species formed by electron detachment during storage were detected to measure the lifetimes of the anions. By virtue of the high sensitivity for metastable species, we found that shortlived anions with milliseconds lifetime were formed in the ion source.