Laser techniques implementation for wall surface characterization and conditioning

Plasma-facing components (PFCs) at ITER are eroded and the material is transported by the edge plasma to areas with net deposition. The distribution, thickness and composition of layers formed will be strongly inhomogeneous. Current knowledge of the wall conditions is essential for a safe operation of ITER. To ensure operation within given margins methods have to be applied regularly to monitor the tritium inventory and deposited material and reduce it on occasion.Laser-based techniques might be suitable for the in situ characterization of the local wall condition of PFCs. Laser impact induces the release of particles, which are spectroscopically analysed. Codeposited hydrogen isotopes are measured by laser-induced desorption spectroscopy during a discharge. Laser-induced ablation spectroscopy and laser-induced breakdown spectroscopy can determine the material composition during and between discharges, respectively.Laser desorption and ablation can also be applied for wall conditioning at ITER using the remote handling arm.