Test Results of HD1b, an upgraded 16 Tesla Nb3Sn DipoleMagnet
The Superconducting Magnet Group at Lawrence Berkeley National Laboratory has been developing high-field, brittle-superconductor, accelerator magnet technology, in which the conductor's support system can significantly impact conductor performance (as well as magnet training). A recent H-dipole coil test (HD1) achieved a peak bore-field of 16 Tesla, using two, flat-racetrack, double-layer Nb{sub 3}Sn coils. However, its 4.5 K training was slow, with an erratic plateau at {approx}92% of its un-degraded ''short-sample'' expectation ({approx}16.6 T). Quench-origins correlated with regions where low conductor pre-stress had been expected (3-D FEM predictions and variations in 300 K coil-size). The coils were re-assembled with minor coil-support changes and re-tested as ''HD1b'', with a 185 MPa average pre-stress (30 MPa higher than HD1, with a 15-20 MPa pole-turn margin expected at 17 T). Training started higher (15.1 T), and quickly reached a stable, negligibly higher plateau at 16 T. After a thermal cycle, training started at 15.4 T, but peaked at 15.8 T, on the third attempt, before degrading to a 15.7 T plateau. The temperature dependence of this plateau was explored in a sub-atmospheric LHe bath to 3.0 K. Magnet performance data for both thermal cycles is presented and discussed, along with issues for future high-field accelerator magnet development.
- Research Organization:
- Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA(US)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of High EnergyPhysics
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 887432
- Report Number(s):
- LBNL-54894; R&D Project: 454001; BnR: KA1502010; TRN: US0604262
- Resource Relation:
- Conference: Applied Superconductivity Conference,Jacksonville, FL, Oct 3-8, 2004
- Country of Publication:
- United States
- Language:
- English
Similar Records
HD1: Design and Fabrication of a 16 Tesla Nb3Sn DipoleMagnet
HD1: Design and Fabrication of a 16 Tesla Nb3Sn Dipole Magnet