The mechanism and dynamics of ion expulsion are studied using a combination of time of flight mass spectrometry and pump probe techniques. Coulomb explosion is identified as the dominant mechanism for ion emission under low fluence/low number of laser shots irradiation ('gentle' ablation regime) as a direct consequence of the electronic mediated energy transfer to the sample. After sufficient incubation due to the defect accumulation following repetitive irradiation ('strong' ablation regime) the ablation rate increases with almost on order of magnitude, the ionization efficiency decreases and the velocity distribution are shifted to lower values.
|Number of pages||1|
|State||Published - 2000|
|Event||Conference on Lasers and Electro-Optics (CLEO 2000) - San Francisco, CA, USA|
Duration: 7 May 2000 → 12 May 2000
|Conference||Conference on Lasers and Electro-Optics (CLEO 2000)|
|City||San Francisco, CA, USA|
|Period||7/05/00 → 12/05/00|