SURFACE ACOUSTIC-WAVES AS HIGH-FREQUENCY SOUND TRANSDUCERS IN GASES

In order to increase the frequency range of acoustic measurements in gases surface acoustic waves have been used for excitation and detection-of sound waves. With this technique the acoustic attenuation in He, Ar, and He-Ar mixtures at 180 MHz was measured. The results will be compared with data from the literature, obtained with piston-like moving transducers (x-cut quartz or Sell transducers) at frequencies below 10 MHz.