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Abstract
| The Nb$_3$Sn FRESCA2 dipole magnet is dedicated
to upgrade the CERN cable test facility FRESCA. It is also a
technological demonstrator of large-aperture Nb$_3$Sn accelerator
magnet. It has an aperture of 100 mm and a target bore magnetic
field of 13 T. It is composed of four 1.5-m-long double-pancake
“block-type” coils, manufactured following the wind, react and
impregnation technique. It is developed by CEA and CERN in the
framework of a collaboration agreement, in the continuity of the
EuCARD program. Through the fabrication of two full-scale copper prototypes, the different steps of the coil fabrication process
(winding, heat treatment, splicing, instrumentation, impregnation,
and transport) and the corresponding tooling have been adjusted.
The final winding and reaction procedure integrates the possibility to open longitudinal gaps in the winding table and in the
central post, in order to accommodate partially the longitudinal
contraction of the cable during reaction. This new feature has
been experienced through full-scale tests using superconducting
cable with a reduced number of turns. This paper reports on the
fabrication procedure of these coils. The production phase of the
superconducting magnets has started in June 2015. |