TIME-RESOLVED STUDIES OF ION DESORPTION FROM CA SURFACES USING DOUBLE-PULSED LASER-ABLATION TECHNIQUE

We have performed double-pulsed laser ablation experiments on Ca sampl es with an ArF excimer laser. The amount of desorbed monovalent ions w as measured using a quadrupole mass spectrometer as a function of the delay between the laser pulses. In the case of 6 ns delay, the total a mount of desorbed ions is decreased to approximate to 0.1 times that w ith no delay. On the basis of this result, it is discussed that the la ser ablation of Ca metal is caused by multiphoton photochemical reacti on via a lattice/defect-assisted mechanism.