Lawrence Berkeley National Laboratory

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.