Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet

LBNLA8318 SC-MAG 747 FABRICATION AND TEST RESULTS OF A HIGH FIELD, NB 3 SN SUPERCONDUCTING RACETRACK DIPOLE MAGNET* R. Benjegerdes, P. Bish, D. Byford, S. Caspi, D.R. Dietderich, S.A. Gourlay, R. Hafalia, R. Hannaford, H. Higley, A. Jackson, A. Lietzke, N. Liggins, A.D. McInturff, J . O'Neill, E. Palmerston, G Sabbi, R.M.Scanlan, J. Swanson Lawrence Berkeley National Laboratory, Berkeley, California, 94720 Abstract The LBNL Superconducting Magnet Program is extending accelerator magnet technology to the highest possible fields. A I meter long, racetrack dipole magnet, utilizing state·of-the-art Nb 3 Sn superconductor, has been built and tested. A record dipole filed of 14.7 Tesla has been achieved. Relevant features of the final assembly and test results are discussed. 1 INTRODUCTION The goal . of the LBNL Superconducting Magnet Program is to develop the technologies associated with very high field superconducting magnets. Cost-effective options will be needed for the next·generation high- energy physics accelerators such as the Very Large Hadron Collider and muon/collider rings. Simplicity is a key element of any cost-effective design and the Common-Coil racetrack [1,2], with its intrinsic dual- bore geometry, is an attractive candidate. Consequently, Figure I. RD-3 (Fig. 2) shows the 3-layer design: two double·pancake outer coils and a single-layer inner coil. The general magnet parameters are given in Table I. Coli Module. Iron Yoke our program is primarily focused on the development of options offered by this design. Past work can be found in Generating fields above 10 Tesla requires the use of AI5 compounds that are brittle and strain sensitive. For the foreseeable future, Nb,Sn is the most practical conductor available. For high field applications . a concurrent development program [7] is required to reduce conductor cost and improve performance. Following the successful test of a 6 Tesla racetrack magnet (RD-2)[4J, we have been focusing on the design and fabrication of a 14 Tesla magnet (RD-3), at the edge of current technology, Fig. I. Keys Iron Pole Iron Support PAd 2 DESIGN Aluminum ShAll Details of the design and fabrication steps of RD-3 have been described elsewhere [6]. A cross section of RD-3 Figure 2. RD-3 Cross Section ·This work is supported under contract # DE·AD03-76SF00098 by the Director. Office of Energy Research. Office of High Energy Physics. U.S. Department of Eoergy For high fields, conductor performance is very important. The conductor, manufactured by Oxford Superconducting Technology, Inc, had a J, over 2,000 Nmm 2 , three times that used for RD-2.