Set-up for neutron depolarization studies

Polarized neutron beam extracted from the IRT-Sofia research reactor has been used for neutron depolarization investigations. The experimental set-up allows to measure the magnitude of the polarization vector. It consists of a steel-made and 58Ni mirror collimators, a neutron-guide mirror and two polarizing neutron guide-tubes used as polarizer and analyzer. The polarizing mirrors are magnetized to saturation by a constant magnetic field H=500 Oe applied in vertical direction. The magnitude of the projection of the polarization vector is measured by a flipper, analyzer and a 3He counter. Time-of-flight technique using a slotted cadmium disc-type mechanical chopper and a 400-channel time-analyzer was applied to measure the exit spectra of the polarizer and the analyzer. The spectra are presented and discussed. 4 figs., 10 refs