Five-metre neutron polarizing guide-tube at the Leningrad nuclear physics institute

Abstract A 8.5 × 60 mm 2 5 m neutron polarizing guide-tube based on 60% Co−40% Fe mirrors with a 85% Ti−15% Gd absorbing underlayer is described. The design of the neutron guide-tube and the test results on the WWR-M reactor at the LNPI are presented. The average flux at the exit of the neutron guide-tube was 1.5 × 10 6 n/cm 2 s for a 15 MW reactor, the peak of the exit spectrum lies at the wavelength of 2.2 A, and the polarization averaged over the whole spectrum was no less than 96%.