Testing of TAMU1: A single-aperture block-coil dipole

The NbTi model dipole TAMU1 was successfully tested at Lawrence Berkeley Lab. The dipole reached 88% of short-sample current on the first quench, and trained rapidly to 98%. The incorporated quench heaters were capable of inducing a plateau quench in <10 msec. The splice resistance was measured to be 0.28 n/spl Omega/ in the multi-kA range, indicating an excellent contact. AC loss properties were studied during ramp studies. Ramps to 1,000 A/s (0.9 T/s) operated at greater than 60% plateau current. The dipole is a success. It is significant that this high-field NbTi dipole operated successfully at short-sample current with minimal training, even though the coil was vacuum-impregnated with epoxy. We attribute this performance in part to the stress management that is integrated into the block-coil geometry.