Review of the acceptance tests of the W7-X superconducting magnets

The W7-X magnet system consists of 50 non-planar coils of five different types and 20 planar coils of two different types. Factory tests of the non-planar coils are carried out at the manufacturer site of Babcock-Noell, Germany, and for the planar coils at Tesla Engineering, UK. They consist of electrical insulation checks, mass flow measurements, leak tests and sensor checks. In the test facility of CEA Saclay, France, each coil is cooled down to ∼5 K and operated at nominal current. At least one coil of each type is quenched by increasing the inlet temperature. Results of the mass flow measurements and the quench tests are presented. The manufacturing and testing progress is reviewed and the impact of technical failures is discussed. In conclusion, the scope of the tests allows a very strict quality control. This experience is highly beneficial for the construction and testing of similar components for future superconducting fusion experiments.