Superconducting wire test

An extensive and systematic measurement on niobium-titanium superconducting wire for the Energy Saver/Doubler project has been carried out. The measured characteristics are short sample data, hysteresis loss and ac loss. The effect of field orientation on the hysteresis and ac loss of the wire was measured for both soldered and unsoldered cable. The hysteresis loss curves are found to have different characteristics depending on the field orientation. In the case of soldered cable the coupling current between the strands is confirmed to be serious, especially with the wide face perpendicular to the field. The ac loss of several small dipole magnets was also measured by using an on-line computer system, and the results are compared with calculated values based on sample wire measurement. In the ac loss measurement of these magnets we observed two breaks in the excitation curve. The one at low field is attributed to complete flüx penetration into the filaments and the other at high field to wire movement.