A highly efficient polarimeter for the medium resolution spectrometer at TRIUMF

A polarimeter which uses inclusive scattering from carbon has been mounted after the focal plane of the TRIUMF medium resolution spectrometer. Four drift chambers measure scatterings at all azimuthal angles out to 20° in polar angle over a spectrometer momentum acceptance of ± 5%. A microprocessor rejects events with small scattering angles. The efficiency for 400 MeV protons is 4%, and for 295 MeV deuterons is 1.5%. Analyzing powers for protons are similar to those previously reported for polarimeters of this type.