AC loss measurements of model and full size 50 mm SSC collider dipole magnets at Fermilab

Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5-m-long model magnets and eight 15-m-long full-scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500 to 5000 A for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle were digitally integrated to yield the energy loss per cycle. Measurement reproducibility was typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar magnet types agree to within experimental error, while eddy current losses correlate strongly with the observed dependence of quench current on ramp rate.<
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