PNNL-13501 - Pacific Northwest National Laboratory

Figure 1. Image of high-frequency ultrasonic bulk waves
arriving at the surface of an aluminum block, from data
taken at INEEL. The vertical bands are the primary
wavefronts from the transducer. Shadowing by internal
defects is theoretically present, but is not observable.
Figure 2. Theoretical image reflected from single hole, with
alternating light and dark circular regions
414 FY 2000 Laboratory Directed Research and Development Annual Report
A hazy spot was observed corresponding to the optical
illumination. No perturbations attributable to the
ultrasonic energy could be detected. However, at a lower
frequency and slightly different geometry, others
(INEEL) were able to obtain a surface image of an
internal reflector (Figure 3).
Figure 3. Actual image reflected from single hole, lower
frequency
Summary and Conclusions
Full-field ultrasonic imaging of transmitted ultrasound on
a solid surface at a high ultrasonic frequency was
obtained. An image from an internal reflector was
observed at a lower frequency.
Acknowledgments
Imaging on the solid surfaces was carried out at INEEL
under the direction of Vance Deason and Kenneth
Telschow. Image conversion and enhancement were
performed at this Laboratory by Charles Batishko.
Frequency-domain analyses were conducted by
David Sheen.