Performance of the neutron polarimeter NPOL3 for high resolution measurements

We describe the neutron polarimeter NPOL3 for the measurement of polarization transfer observables Dij with a typical high resolution of ∼300 keV at Tn≃200MeV. The NPOL3 system consists of three planes of neutron detectors. The first two planes for neutron polarization analysis are made of 20 sets of one-dimensional position-sensitive plastic scintillation counters with a size of 100 cm × 10 cm × 5 cm, and they cover the area of 100×100cm2. The last plane for detecting doubly scattered neutrons or recoiled protons is made of the two-dimensional position-sensitive liquid scintillation counter with a size of 100cm×100cm×10cm. The effective analyzing powers Ay;eff and double scattering efficiencies εD.S. were measured by using the three kinds of polarized neutrons from the 2H(p⇒,n⇒)pp, 6Li(p⇒,n⇒)6Be(g.s.), and 12C(p⇒,n⇒)12N(g.s.) reactions at Tp=198MeV. The performance of NPOL3 defined as εD.S.(Ay;eff)2 are similar to that of the Indiana Neutron POLarimeter by taking into account for the counter configuration difference between these two neutron polarimeters.