Design overview of the ITER core CXRS fast shutter and manufacturing implications during the detailed design work

•Keeping key parameters during design has facilitated quick iteration assessment.•Proper pipe bending and welding procedures were established for manufacturing.•Bellows assemblies and manufacturing were adequately defined for the actuator.•Successful cooperation between our in-house workshop and the industry.•Full shutter manufacturing drawings were successfully developed. At first a detailed fast shutter design was finalized for the ITER core charge exchange recombination spectroscopy (CXRS) diagnostic. The shutter has approximately 70kg of mass and a length of 2.1m. It operates in fractions of a second (0.7s) protecting critical optical components against degradation and providing means of calibration for the optical system. The shutter structure is driven by a bidirectional frictionless helium actuator, with forces and axial strokes of 3.4kN and 2mm respectively. The shutter structure consists of: (a) two blades made of CuCrZr and stainless steel, calibration surfaces (currently Al2O3) on the top and on the bottom a protective TZM (Mo–0.5Ti–0.08Zr) screens, (b) two arms interconnected that form one cooling circuit including the blades, (c) a bumper system to limit the arms movement, and (d) a support. A description of these components and their functions are given in this paper, followed by some issues, and their corresponding solutions or ongoing investigations, encountered during the design work. Detailed manufacturing drawings have been developed as the deliverable final product of this design stage, and are used in the prototyping phase which includes testing, numerical benchmarking, and validation of the shutter concept.