Electron detachment spectroscopic study on carbon and silicon cluster anions

The electron detachment of mass-selected carbon and silicon cluster anions was studied using different ion-source conditions. Ultraviolet photoelectron spectra of medium-sized carbon cluster anions were measured using a laser vaporization source with different fluences. On systematic inspection, the series of spectra showed 4n-periodicity in their electron affinity, which is consistent with the predicted ring-form structure. For silicon cluster anions, resonance-enhanced multiphoton electron detachment spectra were measured. The role of the carrier gases He, N2 and CO2 is discussed.