Field Quality Control Through the Production Phase of RHIC Arc Dipoles

The field quality in the arc dipoles built thus far for the Rel-ativistic Heavy Ion Collider (RHIC) not only meets machine requirements1 but is significantly better than that expected from scaling laws based on previous large scale superconducting magnet production for particle accelerators. In this paper we describe the evolution of the present cross section and the de-sign philosophy that has led to these improvements. The tech-niques described here have been found quite efficient to adopt in the production environment, where schedule and cost consider-ations become important. Moreover, the techniques developed during the R&D program have resulted in making the saturation induced harmonics negligible, despite the fact that the iron is very close to the coil