FORCE Seminar 2/28: Robert Liebermann

Robert Liebermann
Stony Brook University

"Ultrasonic Measurements of Sound Velocities at High Pressures and Temperatures"

Following the invention of piezoelectric transducers and the development of ultrasonic interferometry techniques at the Bell Telephone Laboratory, several U.S. mineral physics labs began in the 1960s to utilize these developments to measure sound velocities in rocks and minerals; these included Francis Birch at Harvard, Orson Anderson at Lamont, Gerhard Barsch at Penn State, Hartmut Spetzler and Rick O’Connell at Caltech and Gene Simmons at MIT.  Over the subsequent half century, the ultrasonic techniques have continued to develop and the velocity measurements have been conducted at ever-increasing pressures, now reaching conditions of the lower mantle. .  In our high-pressure laboratory at Stony Brook, these studies have been led by Baosheng Li and his graduate students and postdocs in collaboration with Ian Jackson and Sally Rigden of the ANU.  This talk will summarize this history from my personal perspective, from my 1966 experiments with Ed Schreiber on hematite to 3 kilobars [0.3 GPa] in a gas high-pressure apparatus in the Mineral Physics Laboratory at Lamont to the most recent work on the same hematite specimen by Baosheng Li and his postdoc Ran Wang to 13 GPa [130 kilobars] in our 1000-ton uniaxial split-cylinder apparatus [USCA-100] in the Stony Brook High-Pressure Laboratory.  Many recent studies of the sound velocities of minerals at high pressures and temperatures have been conducted at the synchrotron X-radiation facilities of the U.S. Department of Energy, including the National Synchrotron Light Source [NSLS] at the Brookhaven National Laboratory and the Advanced Photon Source [APS] at the Argonne National Laboratory.