Effect of Prestress on Performance of a 1.8 m SSC R&D Dipole

A series of 1.8m SSC dipoles is being built and tested as part of the R&D program. One of the 40 mm — aperture magnets was tested with a standard assembly and then reassembled and retested in a special configuration which had significantly less azimuthal prestress than the initial assembly. We report quench, coil stress, end force, and harmonics data for each of the assemblies. Quench performance was not degraded for the low-prestress assembly.