Prof. Thomas Duffy [Dept. of Geosciences, Princeton University, USA]

Title: Dynamic Compression: From Meteorites to Exoplanets

Time: 10:00 - 11:00 AM, Tuesday, August 9, 2016

Place: Auditorium Room 410, HPSTAR (Shanghai)

Host: Dr. Li Zhang

Abstract:

Dynamic compression studies have wide-ranging applications to problems in Earth and planetary science ranging from the effects of impacts and explosions to the synthesis of new phases.  In this talk I will describe two major new advances in this area.  Laser-based dynamic compression provides opportunities to study the structures and properties of geological materials to ultrahigh pressure conditions reaching 1 terapascal and beyond.  By controlling the shape and duration of the incident laser pulse, either shock or ramp (shockless) loading can be produced. By combining these techniques with pulsed x-ray diffraction, we have explored a variety of materials including iron silicide, magnesium oxide, and carbon to ultrahigh pressures relevant to exoplanet interior conditions.  A second major new development is the Dynamic Compression Sector at the Advanced Photon Source which provides the capability to couple gas-gun shock-wave experiments with brilliant synchrotron X-rays.  Here I will show preliminary results on the lattice-level structural response of quartz and fused silica under shock loading that provide a new understanding of the behavior of silicate minerals under dynamic compression.

Biography of the Speaker:

Prof. Thomas S. Duffy is a professor at the Princeton University, Department of Geosciences. His research focuses on understanding the large-scale physical and chemical behavior of the Earth and other planets through experimental study of geological materials under extreme conditions of pressure and temperature. In this talk, he will discuss two major new advances in the field of dynamic compression.

Prof. Duffy received his PhD degree in Geophysics from California Institute of Technology in 1992. Before moving to Princeton University in 1997, Prof. Duffy worked as a postdoctoral fellow at the Geophysical Laboratory, Carnegie Institution of Washington and then as a staff scientist at Consortium for Advanced Radiation Sources of the University of Chicago.

Selected publications:

Smith, R. F., J. H. Eggert, R. Jeanloz, T. S. Duffy, D. G. Braun, J. R. Patterson, R. E. Rudd, J. Biener, A. E. Lazicki, A. V. Hamza, J. Wang, T. Braun, L. X. Benedict, P. M. Celliers, and G. W. Collins, Ramp compression of diamond to five terrapascals, Nature, 511, 330-333, 2014.

Duffy T. S., Mineralogy at the extremes, Nature, 451, 269-270, 2008.