Cold yoke dipole magnets for HERA

The proton storage ring of HERA will be equipped with a novel type of superconducting dipole magnet, combining an aluminum-collared coil with a cold iron yoke. The magnet features good field homogeneity, high quench currents, a low heat load on the cryogenic system and the possibility of a passive quench protection system. The magnet is described and test results are presented.