F2D2: A block-coil short-model dipole toward FCC

Helene Felice (1) , Valerio Calvelli (1) , Maria Durante (1) , Philip Mallon (1) , Pierre Manil (1) , Jean-Francois Millot (1) , Gilles Minier (1) , Etienne Rochepault (1) , Alexandre Bord (2) , Simon Perraud (1) , Susana Izquierdo Bermudez

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 ENSEM - Ecole Nationale Supérieure d'Electricité et de Mécanique

In the framework of the Future Circular Collider (FCC) program, and in collaboration with CERN, CEA is developing a 1.5-m-long single aperture Nb$_3$Sn block dipole. The so-called FCC Flared-end Dipole Demonstrator (F2D2) will produce at least 15 T with 14% margin at 1.9 K and will be assembled in a shell-based support structure. Its magnetic design is derived from the block-coil option proposed in the EuroCirCol studies and relying on graded cables for improved efficiency. The design uses identical strand dimensions but a lower critical current density according to the performance of a currently available conductor. The main challenge of this magnet lies in the concepts of joints between the conductor grades, which will be implemented for the first time in a Nb$_3$Sn block dipole. After presenting the overall design of the magnet from a magnetic and mechanical standpoint, chosen fabrication techniques are detailed.

Mots clés: Hafnium; Superconducting magnets; Conductors; FCC; Cable insulation; Apertures; Niobium-tin; critical current density (superconductivity); niobium alloys; superconducting coils; superconducting magnets; F2D2; Future Circular Collider program; 1.5-m-long single aperture Nb; FCC Flared-end Dipole Demonstrator; magnetic design; block-coil option; critical current density; single aperture Nb3Sn block dipole; block-coil short-model Dipole; shell-based support structure; temperature 1.9 K; magnetic flux density 15 T; Nb3Sn; Block dipole; Nb $_{3}$ Sn; superconducting accelerator magnet; activity report; magnet: superconductivity; magnet: design; niobium: tin; bending magnet; fabrication; mechanical engineering

Domaines: Physique des accélérateurs [physics.acc-ph]

Helene Felice, Valerio Calvelli, Maria Durante, Philip Mallon, Pierre Manil, et al.. F2D2: A block-coil short-model dipole toward FCC. IEEE Transactions on Applied Superconductivity, 2019, 29 (5), pp.4001807. ⟨10.1109/TASC.2019.2897054⟩. ⟨hal-02283586⟩