Title :
Experimental verification of acoustic saturation
Author :
Sempsrott, J.M. ; O´Brien, W.D., Jr.
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA
Abstract :
The maximum value of acoustic pressure within an ultrasonic beam is limited by acoustic saturation. The theoretical basis for acoustic saturation has been analyzed previously. In this work, a high-power pulse source is used to drive acoustic pressure levels from an ultrasonic beam to saturation. An automatic procedure determines the field´s beam axis using a calibrated Marconi PVDF hydrophone. The hydrophone measured RF waveforms are recorded along the beam axis and analyzed off-line. The peak compressional pressure is evaluated as a function of distance along the beam axis. The overall maximum pressure is compared to theoretical predictions. Three-, six-, and nine-MHz center frequency, 19-mm-diameter transducers were analyzed. The longer focal length transducer saturation level was comparable to a theoretical prediction. However, the theoretical saturation level for the shorter focal length transducers underestimated experimental results
Keywords :
biomedical ultrasonics; hydrophones; radiation pressure; 19 mm; 3 to 9 MHz; acoustic pressure maximum value; acoustic saturation; acoustic saturation verification; beam axis; calibrated Marconi PVDF hydrophone; high-power pulse source; longer focal length transducers; peak compressional pressure; shorter focal length transducers; theoretical saturation level; Acoustic beams; Acoustic measurements; Acoustic pulses; Acoustic transducers; Acoustic waves; Equations; Nonlinear acoustics; Pulse measurements; Radio frequency; Sonar equipment;
Conference_Titel :
Ultrasonics Symposium, 1999. Proceedings. 1999 IEEE
Conference_Location :
Caesars Tahoe, NV
Print_ISBN :
0-7803-5722-1
DOI :
10.1109/ULTSYM.1999.849232
