2aPA2. Velocity measurements in molten materials with the use of laser-generated ultrasound.
Session: Tuesday Morning, December 3
Author: Hidetoshi Nakano
Location: Natl. Res. Lab. of Metrology, 1-1-4, Umezono, Tsukuba-shi, Ibaraki, Japan
Author: Youichi Matsuda
Author: Shoichirou Shin
Author: Satoshi Nagai
The temperature dependence of the longitudinal ultrasonic velocity
in solid and molten materials was measured by using laser-generated ultrasound.
A Q-switched Nd--YAG laser was used for the generation of the ultrasound source.
A diode-pumped cw laser or a long-pulse Nd:YAG laser probed the sample, and then
the scattered light from the sample was collected into a multimode optical
fiber. The light from the fiber was introduced to a Fabry--Perot interferometer
to detect the ultrasonic motion. The velocities of solid materials were compared
with those by a conventional pulse-echo method at room temperature. These
results were in agreement within 0.1%. A transparent cell was used as a
container for molten samples. Thus the ultrasound was generated at the boundary
between the sample and the container, and detected at the opposite boundary
through the cell. The velocities were measured up to 1000 (degrees)C, which was
limited by the furnace.
ASA 132nd meeting - Hawaii, December 1996