| Popis: |
If the epithermal activation Cep of a foil detector is derived from its epicadmium activation CCd, the knowledge of the cadmium correction factor F Cd = C ep C Cd is usually required. The cadmium correction factors of V, B, 10B, In, Au, Mn, Co, and Dy foil detectors of thickness 0·0·25 mm and cadmium cover thicknesses of 0·5, 0·8, 1·0, and 1·2 mm have been numerically evaluated according to the most recent cross-section values and resonance parameters. Fcd values are listed for both monodirectional and isotropic neutron incidence. While for most of these materials no results have been published so far, for gold and indium the results could be compared with previous calculations and measurements and a discussion of the results is given. Since the FCd values, particularly for Mn, Co, and Dy, exceed unity considerably, neglecting this correction is not tolerable with precise measurements of the thermal neutron flux density. Comments on the use of FCd values in the Westcott convention are added. |
