FACILITY FOR THE (P,N) POLARIZATION TRANSFER MEASUREMENT

We have designed and constructed a facility to measure the complete po larization transfer coefficient D-ij for the (p, n) reaction at interm ediate energies. The facility consists of a beam swinger dipole magnet used for angular distribution measurements and a 100 m tunnel for the neutron energy measurement by the time-of-flight method, Typical neut ron energy resolution is about 1.85 MeV for 290 MeV neutrons including a contribution of 1 MeV due to the target thickness. The background a ssociated with this tunnel system was carefully investigated and found to be negligibly small. A dipole magnet for the neutron spin rotation is installed in the neutron flight path to measure the longitudinal p olarization as well as the induced polarization. The neutron polarimet er which consists of 6 planes of the two-dimensional position-sensitiv e neutron detectors with a size of 1 m X 1 m x 0.1 m has been construc ted. Its effective left-right analyzing power (A(y)(eff)) has been cal ibrated at 194, 290 and 384 MeV. The figure-of-merit value defined by (A(y)(eff))(2) X epsilon(DS) at 290 MeV is 4.05 X 10(-4), where epsilo n(DS) is the double scattering efficiency.