BNL, Upton, Long Island, New York, USA
In this report we present studies of and measurements from the RHIC ionization profile monitors (IPMs). Improved accuracy in the emittance measurements has been achieved by (1) continual design enhancements over the years, (2) application of channel-by-channel offset corrections and gain calibrations in the beam profile measurements and (3) use of measured beta functions at the locations of the IPMs. The removal of systematic errors in the emittance measurements was confirmed by the convergence of all four planes of measurement (horizontal and vertical planes of both the Blue and Yellow beams) to a common value during beam operations with stochastic cooling. Consistency with independent measurements (luminosity-based using zero degree counters) at the colliding beam experiments STAR and PHENIX was demonstrated.
