Test of the High-Field Nb$_3$Sn Dipole Magnet HD3b

Author(s): Marchevsky, M; Joseph, J; Lizarazo, J; Roy, PK; Sabbi, G; Salmi, T; Turqueti, M; Wang, X; Prestemon, S; Caspi, S; Cheng, DW; Dietderich, DR; DiMarco, J; Felice, H; Ferracin, P; Godeke, A; Hafalia, AR | Abstract: © 2013 IEEE. We report test results for the one meter long dipol HD3b, a block-Type accelerator quality Nb3Sn magnet built a LBNL with operational bore fields in the range of 13-15 T. Th magnet is an upgrade of the previously reported HD2 and HD3 versions, with several modifications implemented to improve conducto positioning, reduce cable "hard-way" bending radius, an strengthen electrical insulation between cables and coil parts The magnet exhibited long training behavior, but showed a goo "memory" of the trained state upon thermal cycling. Ramp-rat dependence of the quench current, field quality performance characteristics and protection heater studies were conducted. Quenc propagation velocity and quench locations were determined base on the voltage signals; quench localization was further improve using inductive quench antenna and acoustic emission sensors Short-And long-Term acoustic precursors to quenching wer observed.