الفهرس | Only 14 pages are availabe for public view |
Abstract The present work deals with the calculations and experimental measurements carried out for the neutron guide. system recently installed at one of the ET-RR-1 reactor horizontal channels. It is attached to the Cairo Fourier Diffractometer Facility (CFDF) and consists of a main Curved Neutron Guide Tube(CNGT), to deliver thermal neutrons, free from fast neutrons and y-rays background, to a Fourier chopper, and a Straight Neutron Guide Tube (SNGT); mainly for collimation of the neutron beam, after the chopper, to the sample under investigation.The results of neutron reflectivity and spectrum calculations carried out for Cu, AI, natural Ni and 58Ni were found to be in favour of 58Ni as the best coating for the neutron guide mirror channel walls. The experimental measurements were performed for the neutron reflectivity, ofthe neutron guide sample mirror; integral neutron flux at different points of the NG system and the neutron spectrum at the sample position. It was found, both from measurements and calculations, that the neutron spectrum emitted from the NG system covers the neutron wavelength range from 1 - 4 A ; with a maximum at 1.4 A. The latter value is consistent with the value 1.377 A calculated for the curved neutron guide characteristic wavelength. |