Ten years of cryomagnetic W7-X test facility construction and operation

The construction, commissioning, and operation phases of the W7-X cryomagnetic test facility in CEA Saclay lasted ten years. The large diversity of equipments called, specialties involved and problems solved attest the expertise that was required to operate the test facility and test the coils. Nearly one hundred cryogenic tests were performed on the seventy W7-X coils, at a rate always increasing, using two cryostats each holding two coils.This paper presents the test facility and its operation first, the cryogenic difficulties that were confronted with their solutions, the electro-magnetic difficulties encountered along with corrective actions, and finally the instrumentation and data acquisition aspects.

► Experience from operating a large superconducting magnet test facility is shared.
► Equipments, human resources, safety assessment and testing campaigns are described.
► Main cryogenic difficulties: leaks and pollution are depicted with solutions.
► Critical electrical difficulties were insulation from high voltage.
► Magnet control system, magnet safety system and instrumentation are presented.