R. Shaw1, M. Friend1, H. Gonzalo2, J-L. Helary1, D. Maisonnier3, A. Oikawa1, F. Olezza2, F. Puhn1, A. Timperi3
1. ITER EDA, 11025 N. Torrey Pines Road, La Jolla, CA 92037, USA
2. EFET consortium, European Fusion Technology Programme
3. The NET Team, Max-Planck-Institut fŸr Plasmaphysik, Garching, Germany
The combination of the overall size of the ITER tokamak, and the tight tolerances to which the major components must be manufactured and aligned, imposes stringent requirements on the dimensional control system. The system must be capable of providing precise, cost effective 3-d positional measurements, in a typical heavy construction environment, with a high degree of reliability.
To satisfy all of the requirements of the assembly process, an integrated metrology system, comprising a framework of primary and secondary datums, component mounted fiducial reference targets and two functionally different, system compatible, instruments has been developed.
Generic procedures, utilising as-built component models, best-fitting techniques, dynamic build datums and OMS-CAD interfaces, have been developed to optimise the performance of the integrated system. Conceptual procedures have been validated via a series of functional tests.
The paper will describe the framework of the integrated system, including the network of datums, targets and instruments. The strategies and concepts developed to ensure achievement of the ITER requirements will be described and a specific procedure elaborated to illustrate each stage of the process.