SELFIE: ITER superconducting joint test facility

Abstract

In the frame of a contract with ITER Organization (IO) on magnets assembly support, CEA designed and built a superconducting joint test facility called SELFIE (ITER SELf-FIEld joint test facility). This facility is installed at CEA Cadarache and started to operate in 2022.This project was initiated by IO for quality control of critical assembly activities. Indeed, the magnet superconducting joints assembly is a special process, for which the performance cannot be verified until the full Tokamak is at cryogenic temperature and obviously repair cannot be envisaged once the machine is assembled. Therefore, the quality control of these joints assembly relies on procedures and qualification of the workers in charge of their implementation.As the joints assemblies will span over three years of the ITER construction, the qualified workers will have to assemble periodically some Production Proof Samples (PPS) joints to train and keep their certification valid. The purpose of SELFIE is to test these PPS in a timely manner.The tests scope is the measurement of the PPS resistance (few nOhms). For that purpose, PPS integrated in ITER conductors length (∼200 kg weight and 3600 mm length) are tested in a liquid helium bath (4.2 K), at nominal current (up to 70 kA), in self-field. The current is provided by a superconducting transformer integrated in the same cryostat as the sample.CEA finalized the preliminary design in 2019, complying with the requirement to achieve a full test sequence within one week (controlled cool down, test and warm-up), with an optimised operation cost. The detailed design phase was started in April 2020 followed by the manufacturing phase up to mid 2021. SELFIE integration and installation were achieved in December 2021 and the cold commissioning done in January 2022. This paper presents the SELFIE test facility and the first results.