Particle tracking with scintillating fibers and position sensitive photomultipliers

The use of position-sensitive phototubes in conjunction with scintillating plastic fibers for a particle tracking application in a future focal plane polarimeter (FPP) in the hadron arm of the hall A HRS/sup 2/ facility at the Continuous Electron Beam Accelerator Facility (CEBAF). Current results indicate that the design parameters of the FPP in the hadron arm of the double spectrometer facility HRS/sup 2/ can be met with a design which couples round or square fibers 3 mm in size to Hamamatsu R4135 phototubes. Position resolutions sigma /sub x/ or sigma /sub y/ on the order of 0.6 mm are obtained in the phototubes. Detector structures with staggered double fiber layers lead to overall resolution of sigma =1 mm, and detection efficiencies close to 1. The characteristic speed of these detectors makes them particularly appropriate for the high rates which are expected with the 200- mu A continuous wave beam at CEBAF.<>