It was demonstrated that oscillations in the dependence of the acoustic radiation force on the distance between a focusing piezoelectric source and a spherical scatterer can be reduced by adding a layered structure consisting of plane-parallel acrylic glass plates to the space between the transducer and the scatterer. It was experimentally confirmed that the formation of standing waves, which cause oscillations, is minimized by absorbing and scattering acoustic waves reflected from the source. The ability to control the oscillation level by varying the number of plates was shown. The theoretically calculated radiation force levels in the presence of the layered structure agree with those measured.
Petrov et al. (Thu,) studied this question.