X. Workshop on Resistive Plate Chambers and Related Detectors

Many significant questions remain to be answered about the origin of the proton spin. A new fast Resistive Plate Chamber (RPC) based trigger system is being developed for the PHENIX muon spectrometer arms that will allow for the first time the measurement of the flavor structure of the quark polarization in the proton through the observations of W-bosons in polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The new PHENIX Muon Trigger will improve the efficiency by which the data acquisition system can identify potential W events by approximately two orders of magnitude. W-bosons can be detected through the appearance of a highenergy muon in one of the two existing muon spectrometers. The trigger upgrade is based on new front-end electronics for the muon tracking chambers and RPCs that will be installed in two stations of both muon arms. Components of the RPCs were fabricated at many different locations around the world. After they were shipped to BNL, these components are tested and then the RPC modules are constructed. Once assembled, these modules are extensively tested and jointed in half octant units for installation into the PHENIX spectrometer. Results from a series of quality control tests including tests on a cosmic test stand will be presented.