Imaging analysis of ps laser induced ablation spectroscopy and mass spectrometry − deuterium depth resolution, removal fraction, and uncertainties

• ps-Laser induced ablation craters investigated by 3 He MeV ion beam analysis. • 1260 point ion beam imaging of D content reveals crater details. • Investigation of 6 uncertainty contributions to LIA quantification of D. • Thermal effect significantly contributed to µm scale ablation crater signal. • Crater edge and shape can introduce significant deviation of assumed ablation area. Laser based surface composition analysis methods are used as an in-situ tool for material analysis in nuclear fusion reactors. The methods investigated here ablate material from the surface and analyse the surface composition through the released particles. A quantification requires the calibration of the detection efficiency of the released material and its relation to the affected surface area and depth. Only with this quantification, the laser methods can provide quantitative data on hydrogen isotope retention and plasma-surface interaction. In this work, we combine three high-resolution imaging techniques to provide a complete understanding of the surface structure and elemental composition using a ps-Laser ablating ∼5 µm of W. MeV ion-beam analysis (IBA), in particular with the latest developments regarding high-throughput IBA imaging provides insight into the deuterium content. This enables a new and unique experimental insight into five individual limitations of the deuterium depth resolution and accuracy limitations of laser ablation methods related to the matrix effect. The results enable precise calibration of laser methods and understanding of their limitations. In particular, the thermal desorption halo, the crater-floor depletion fraction, and the impact of crater edge effects are quantified. From sample effect, we see a relative uncertainty of ±9% and an absolute uncertainty of ±52%.