Neutron Scattering

Figure 5 .6 : Partial differential cross section for protonated polystyrene in a deuterated
polystyrene matrix [8] . The concentration of the protonated component is 5% (o) and
0.5% (o) respectively. The curve is a fit with the Debye function .
~E U 0-5
N
0-4
0-3
v
0-2
Y
H O
O
0-1 0-2 0-3 0-4
K .
A_
Figure 5 .7 : Kratky plot of the data from figure 5 .6 .
5.3 Dynamical Correlation Function
5 .3 .1 Correlation Speetroseopy
We consider an observable A of a system which fluctuates randomly because of the thermal
motion of the system . A could be e .g . the pressure on the wall exerted by a gas in a cylinder
or the particle density in a liquid . Figure 5 .8 shows exemplarily the time-dependent value
of a quantity A fluctuating around its average value (A) .
5-1 0