Polarized protons at RHIC

The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50%, high luminosity∼2.0x1032 cm-2 s-1, the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼106 sec per year) would be ∫ Ldt=2x1038 cm-2--- roughly 20 times the total luminosity integrated in ∼10 years of operation of the CERN Collider (∼10 inverse picobarns, 1037 cm-2). This facility would be unique in the ability to perform parity-violating measurements and polarization tests of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders