Conductor development for a wide bore 10 T Nb3Sn model dipole magnet

An 87.8 mm bare single aperture 10 T Nb3Sn model dipole magnet is under dev elopment as a next step in the realization of high-field Nb3Sn dipole magne ts, The magnet is a 2 layer cos(theta)-dipole model as an alternative for t he proposed NbTi D1 beam separator magnets for the LHC. After completion of the general magnetic and mechanical design, all attention is focused on th e manufacturing and cabling of a novel powder-in-tube Nb3Sn conductor. This Nb3Sn conductor is characterized by a high non-Cu J(c) of 2680 A/mm(2)@10 T with an effective filament size of about 20 mu m. Cabling should result i n a Rutherford type of cable exhibiting a moderate I-c degradation due to t he cabling process itself, a low transverse stress sensitivity and a contro llable minimum value of R-c. The conductor development program is presented and the results are evaluated. Progress on the actual realization of the c oils is briefly described.