Neutron Scattering - JUWEL - Forschungszentrum Jülich

6 Vitaliy Pipich
extract information about minimum of the forward scattering, and plot it as function of D2O
content.
Figure 3. Forward scattering as a function of �D2O and �.
Figure 4: Expected results. (Left) the scattering signal in case of �D2O=0.04 and 0.76. In
the amplified inset is the small angle part of the calculated scattering curves. In case of
�D2O=0.04 there is clear suppression of the forward scattering due to the hard sphere
interactions. Calculated scattering curve in case of the sample with �D2O= 0.76 shows no
interaction term. Red curve is pure form factor of PS spheres without taking into account
instrumental resolution function. (Right) Ration between �D2O=0.04 and �D2O=0.76 is
plotted here. So the forward scattering and form factor of both sample are the same, and
in case of �D2O=0.76 sample S(Q) =1, therefore this ratio is the structure factor of
�D2O=0.04 sample.
Next step is the investigation PS spheres in case of sample with D2O content 76% [PS content
0.25%]. This point is located at the local maximum (see Figure 3). At this level of the dilution
the structure factor is definitely undetectable. Please read carefully caption of Figure 4 to
understand the logic of planned experiment.