Improved Devices for the Concentration of Ultrasonic Energy

Abstract

The efficiency of all existing devices for the concentration of ultrasonic energy is considerably lowered by the losses cause by reflection, absorption, and diffraction. These losses, though generally unavoidable, can be minimized in various ways. The choice of suitable materials, use of “matching coatings,” design of “stepped lenses,” and development of “acceleration plates” will be discussed, samples of the improved devices shown and numerical and experimental data given.