Study of multiple femtosecond-pulse laser ablation used in analytical methods

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The ultimative goal of the work is the development of a more versatile and controllable laser sampling system for the introduction of solid materials to analytical instrumentation. The current systems do not have the necessary degree of control over the final state of the material removed from the sample, such as particle size and degree of atomisation. The delivery of multiple femto-second laser pulses to the sample surface may offer the required degree of thermodynamic control. The time-scale of femto-second laser pulses is short compared to thermodynamic equilibration processes in solid material. Delivery of multiple pulses to the sample offers the possibility of controlling the state of the exposed material to a previously impossible degree. Ultra-fast resistance measurements of laser-heated wireds will enable tracking the thermodynamic state of the material, exposing the effects of the laser pulses. Additionally, emission, laser-induced fluorescence, time-of-flight mass spectroscopy and particle size distributions will be monitored to discern the changes of sampling efficiency with pulse sequence.