Accession Number : ADA116329

Title :   Acoustic Microscopy at Cryogenic Temperatures.

Descriptive Note : Summary rept.

Corporate Author : STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS

PDF Url : ADA116329

Report Date : Jun 1982

Pagination or Media Count : 8

Abstract : Some years ago it became evident that research devoted to acoustic microscopy at cryogenic temperatures would allow us to realize the full potential of this new instrument and extend the resolving power beyond the limits imposed by the room temperature microscope. In 1977, the Office of Naval Research agreed to fund such a program at Stanford University. It was to be directed toward an increase in our understanding of the propagation of acoustic waves in cryogenic fluids and the physics of imaging with these waves. We were to concern ourselves with the submicron region. This short report includes a compilation of the written materials and presentations that have resulted from this program. The work of Dr. Logan Hargrove, who has guided the program since its inception, is deeply appreciated. Cryogenic fluids are attractive for propagation of acoustic waves with short wavelengths since the velocity of sound is low and the attenuation is moderate. Much of our work has been done with liquid argon and liquid nitrogen. High quality acoustic images have been recorded in these media and it has been shown that an operating instrument can be a rather simple device.

Descriptors :   Nondestructive testing, *Acoustic signals, *Microscopy, *Cryogenics, Acoustics, Images, Acoustic waves, Mechanical scanning, Liquid nitrogen, Resolution, Liquids, Theory, Fluids, Frequency, Propagation, Instrumentation, Velocity, Nonlinear systems, Temperature, Argon, Sound, Liquid helium, Microscopes, Attenuation, Regions

Subject Categories : Printing and Graphic Arts
      Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE