Characteristic values of contrast lengths

The possibility of controlling the contrast length b enables the experimentalist to deduce the partial structure functions of a mixture from small-angle scattering experiments. 

Let us give characteristic values of the b and let us discuss the range of variation of these lengths. 

1 Contrast lengths for neutron radiation A value of the contrast of species st with respect to SS is given by 

In Table 7.1, the index si refers either to the monomer or to the solvent molecule. Let us note that the ratios b fv vary with temperature and that the variation is not always negligible. 

The values of the by that appear in Table 7.1 for 20 °C are plotted in Fig. 7.2. Let us note that the specific contrast by of a species sd with respect to a solvent is given by the difference by — solven,. 

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