Investigation of two identical superconducting dipoles

This report is devoted to an investigation of the identity of two dipoles SPD-3 and SPD-3´ having the same construction scheme. Independent tests for each magnet were carried out in the same cryostat, including simultaneous precise measurements of field B and current I. One may consider the difference of rations K = B/I for the dipoles as a measure of the magnet identity. The value of K depends on B and rises at low B due to remanent fields. From the measurements, the difference of the curves K(B) for both magnets is about 0.1 per cent. Measured inhomogeneity across the aperture for both magnets does not exceed 4 × 10^-4.