The 2.5-m-long nested corrector prototype, named MCBXFAP1, has been successfully tested in the past weeks in SM18. The magnet reached the operational range at 7.5 TeV (ultimate current) with one quench and showed no retraining after thermal cycle, see plots below.

The magnet was also powered up to 4.5 T m in each dipole simultaneously (well above the operational range) without quenches. This is the long version of the MCBXF nested corrector, whose shorter magnets MCBXFB were already prototyped and industrialized in the past years.

The magnet is part of the collaboration agreement with CIEMAT; coils were manufactured in CIEMAT in 2022, and assembly was done at CERN in 927 laboratories in November 2022. With this test, we have completed the individual test of all magnets needed for the string. The assembly of the long nested corrector with the nine high order correctors in the corrector package cold mass will start in early 2023.

Ezio Todesco, WP3 Leader.