Radiative relaxation times of rovibrational transitions for the electronic ground state of ${\mathrm{HD}}^{+}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}_{}^{18}{}_{}{}^{}$${\mathrm{O}}^{+}$, and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}_{}^{13}{}_{}{}^{}$${\mathrm{C}}^{+}$ 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.

• Received 6 April 1994

DOI:https://doi.org/10.1103/PhysRevA.50.2304