The laser ablation of aluminum at 193, 248, and 351 nm

Pulsed laser ablation of an aluminum target at 193, 248 and 351 nm was investigated by laser induced fluorescence (LIF) spectroscopy. Velocity distributions of the ablated Al atoms were measured directly by monitoring their flight times from the target to the probe laser beam, and by Doppler laser spectroscopy. The velocity distributions resulting from the three wavelengths can all be characterized as hyperthermal, with average velocities of between 4.5 x 10(exp 5) cm/s and 6.5 x 10(exp 5) cm/s over a fluence range of 0.3 to 6.5 J/sq cm. Average values of the Al atom distribution can also be derived by measuring the AlO internal energy distribution of the hot Al atom reaction with low pressures of O2.