Radiative lifetimes in molecules studied by means of fast, molecular ion beams

Radiative lifetimes of excited levels in molecules have been studied by a spectroscopic investigation of the collision processes occurring between fast, molecular ion beams and helium atoms. This technique has been used to measure the lifetimes of the A 2Δ state in CH, the B 2Σ+ state in CO+, and the B 2Σ+ states in CO2+ with an accuracy of 10%–20%. A comparison with previously published results and a discussion on the perspectives of the method have been carried out.