Rotational and vibrational lifetime of isotopically asymmetrized homonuclear diatomic molecular ions

Radiative relaxation times of rovibrational transitions for the electronic ground state of HD⁺, ¹⁶O¹⁸{O}⁺$, and $¹²C¹³C⁺ are calculated. These lifetimes are compared with the storage time in a heavy-ion storage ring where molecular ions can be stored, in order to provide vibrationally and rotationally cold ions. The relevance of the results to the measurement of dissociative recombination of cold molecular ions is discussed.