Photofragmentation of mass‐resolved carbon cluster ions: Observation of a ‘‘magic’’ neutral fragment

Mass‐resolved carbon cluster ions from C+3 to C+20 have been fragmented with 248 nm light. For any initial cluster C+n, the dominant fragment is C+n−3. The fragmentation is primarily linear in laser intensity for n>5, but there are indications that C+3 and C+5 fragment only with the absorption of two or more 248 nm photons. The photodissociation cross sections change dramatically with cluster size.