f-value measurement of the Be I resonance line using a nonlinear time-resolved laser-induced-fluorescence technique

The single-shot time-resolved laser-induced-fluorescence (LIF) technique has been developed further to measure short lifetimes more accurately by considering saturation quantitatively. The temporal and spatial energy distribution in the laser pulses and the separately measured response function of the detection system enter the evaluation procedure. Investigation of LIF anisotropy has shown the necessity for applying the magic angle arrangement as predicted by theory. We obtain standard deviations of 2% for lifetimes around 2 ns. The lifetime of the prominent Be I2s2p¹P₁⁰ level has been measured as 1.85±0.04ns. This value corresponds to an oscillator strength for the resonance transition of 1.34±0.03. A comparison with theoretical and experimental literature data shows excellent to good agreement.