Lifetime of the He2(e), He2(d) and He2(f) states

Starting from the He₂(a) state absorption and induced fluorescence experiments were performed using a narrow band dye laser. The saturation intensity for the He₂(e)←He₂(a) transition yields a radiative lifetime of τ=(67±10) ns. Time resolved measurements of the laser induced fluorescence yield the radiative lifetimes for the states He₂(e): (57±10) ns, He₂(d): (25±5) ns and He₂(f): (19±5) ns. From the time integrated fluorescence data the collisional quenching rates between the above states were determined.