Evaluation\nof a Novel Femtosecond Laser Ablation System\nfor In Situ Analysis Based on Two-Dimensional Galvanometer Scanners

Uneven energy distribution of femtosecond lasers presents\na significant\nchallenge for single-spot analysis, which often leads to concave ablation\ncraters. This study assesses the performance of a femtosecond laser\nablation system for in situ analysis using novel galvanometer scanners.\nA galvanometer rapidly moved the laser beam focus to create craters\nwith a small beam spot. We first examined the inductively coupled\nplasma mass spectrometry (ICP-MS) signal sensitivity to laser parameters,\nestablishing a strong linear correlation with the laser energy, repetition\nrate, scanning ablation area, and galvanometer scanning frequency.\nElemental fractionation analysis of NIST SRM 610 suggests minimal\nbias, with fractionation indices of different elements approaching\nunity. Subsequently, the elemental concentration of six reference\nmaterial glasses was measured by fsLA-ICP-MS to evaluate the elemental\nquantification capabilities of the Galvo-femtosecond laser (Galvo-fsLA).\nThe laser’s capability for in situ U–Pb dating was demonstrated\nby concordant U–Pb ages of five zircon reference materials\nthat are highly consistent with the ID-TIMS ages reported previously.\nFinally, the reliability of the new Galvo-fsLA for isotope analysis\nwas verified by the accurate determination of radiogenic Hf, Pb isotopes,\nand stable Cu isotopes, all agreeing well with their reference values\nwithin uncertainties. These assessments underscore the significant\npotential of Galvo-fsLA for enhanced accuracy and precision of single-spot\nin situ analysis.