Upgraded concepts and design of an in vessel inspection system for fusion reactors

The inspection of the internal wall of the large fusion reactors represents a difficult problem to solve due to the hostile environment, which is characterized by the presence of radiation, temperature, high vacuum and high magnetic field. However, the internal inspection system is essential to verify the status of the components of the first wall and therefore to plan the remote management operations correctly. At the Frascati laboratories, a specific technology was developed that can solve the problem by arriving at a first prototype of a laser measuring system, which passed the conceptual design review phase of ITER. The scanning head of the prototype was based on a rotating prism. More recently a complete overhaul of the system has been made that was based on further experiences of similar systems that have been developed for different fields, such as fine arts and underwater inspection systems. This revision, while maintaining the general concepts of the previous prototype, has completely revised the scanning head. The prism has been replaced with a mirrors based system, thus conceptually avoiding the multiple reflections within the prism itself that limited the accuracy of the old prototype. Furthermore, the new scanning head has been provided with an embedded calibration system with the relative calibration procedures. The new project presently represents an internal development of the Frascati laboratories and has been protected by a patent currently being extended internationally.