  Ultrasound irradiation is a commonly used technique for non-destructive
diagnostics or targeted destruction. We report on a new versatile sonication
device that fits in a variety of standard sample environments for neutron and
X-ray scattering instruments. A piezoelectric transducer permits measuring of
the time-dependent response of the sample in situ during or after sonication.
We use small-angle neutron scattering (SANS) to demonstrate the effect of a
time-dependent perturbation on the structure factor of micelles formed from
sodium dodecyl sulfate (SDS) surfactant molecules. We observe a significant
change during and after sonication and a time-dependent relaxation to the
equilibrium values of the unperturbed system. The strength of the perturbation
of the structure factor depends systematically on the duration of sonication.
The relaxation behavior can be well reproduced after multiple times of
sonication. Accumulation of the recorded intensities of the different
sonication cycles improves the signal-to-noise ratio and permits reaching very
short relaxation times. Due to the flexibility of our new in situ sonication
device, different experiments can be performed, e.g. to explore molecular
potentials in more detail by introducing a systematic time-dependent
perturbation.
