Lifetime Measurements of the 4s^2S_1/2 and 3d^2D States of Aluminum by the Phase-Shift Method

Lifetimes of the upper states of two optical-resonance transitions in aluminum have been measured using the phase-shift method. Data were taken over a large range of fluorescence intensities, to allow for evaluation of the effects of scattered exciting light and radiation entrapment. The results obtained are $\tau 4s^2{S}_{\frac{1}{2}}=7.05$, τ3d²D = 13.70 ± 0.40 nsec.