Multi-channel neutron guides of PNPI: results of neutron and X-ray reflectometry tests

Both polarizing and non-polarizing multichannel neutron guides produced in PNPI (Gatchina) have been considered in the present work. Neutron data for supermirrors on glass, with a critical angle θc in two times exceeding that of Ni, have been represented:• zing FeCoV/TiZr supermirrors with θc=3.4 mrad/Å and the reflectivity 0.75 at this angle, larizing NiC/Ti, NiMo/Ti supermirrors with θc=3.3 mrad/Å and the reflectivity at this angle approaching 0.9. hod of testing multichannel neutron guides by means of neutron and X-ray reflectometry has been developed, which is based on testing single mirrors and then neutron optical systems assembled from them. The results of calculation of the neutron transmittance of single channels have been given. It has been shown that the numerical method developed enables to reliably predict the resultant neutron fluxes at the exit of neutron guides. Moreover, the experimental transmittances of the multi-channel neutron guides have been found to be close to those calculated on assumption of their perfect geometry.