As one of the first CHART projects, the MagDev activity at PSI designed and built a canted-cosine theta (CCT) demonstrator magnet, wound from Nb3Sn conductor. Lasting from February 2017 to October 2019, the activity built a magnet and established a MagDev laboratory for superconducting accelerator-magnet R&D at PSI. After a delay caused by COVID, the magnet was finally tested at CERN in November 2022 and January 2023, reaching a record field and performance level (for a CCT magnet) of 10.1 T in the aperture at 1.9 K and 94% of the estimated maximum performance (called short-sample limit), and 9.9 T at 4.5 K and an exceptional 100% of the short-sample limit. The magnet performance has withstood three thermal cycles and provided a wealth of data for future research.
This result was made possible by the generous support by many actors: CHART and the FCC Design Study, PSI’s magnet section, the Lawrence Berkeley National Lab, and CERN. The experience from this early CHART project has informed our work on magnet development since and leads directly into the R&D on stress-managed magnets that is pursued today.