In situ Tokamak laser applications for detritiation and deposited layers studies
Abstract
Treatments of plasma facing components (PFCs) are major issues for ITER operation. Several goals have to be accomplished during these procedures. Among them control of the tritium inventory is one of the most important in order to fulfil safety requirements. In the following paper, a global solution based on laser techniques is presented. Due to its flexibility, to its capability to reach difficult access structures as voids or castellation and its ability to be embarked on robot, laser offers one of the most suitable solution for detritiation of the PFCs via laser ablation process. High ablation efficiency as well as capability to detritiate deposited carbon layer without any interaction with bulk material will be discussed. Then Laser Induced Breakdown Spectroscopy (LIBS) and a new diagnostic based on the study of the surface temperature response after a repetitive pulsed laser heating will be described. It will be shown that used together, they allow the determination both the concentration of tritium in deposited layer as well as the total quantity of carbon deposited on top of bulk material. These two informations are essential to determine when and how long the detritiation process must take place. Finally, open issues needed to be developed in order to use this global laser system in tokamak will be presented.