RADIATION FORCE ON A SPHERICAL OBJECT IN THE FIELD OF A FOCUSED CYLINDRICAL TRANSDUCER

An exact solution of the radiation force on a spherical object, when p ositioned on the acoustic axis of a cylindrical transducer, is provide d. The solution is valid for any type of sphere of any size. The radia tion force function allows the calibration of high-frequency focused u ltrasound fields from radiation force measurements and expands the uti lity of the elastic sphere radiometer developed by Dunn et nl. [Acusti ca 38, 58-61. (1977)]. Numeral results reveal an oscillatory behavior of the radiation force function for small spheres near the transducer surface and this behavior may present an opportunity for particle sort ing based on the mechanical properties of the particle and other types of manipulation. (C) 1997 Acoustical Society of America.