Dr. Tomokazu Sano [Osaka University, Japan]
Title: Ultrafast Structural Dynamics of Shock-Compressed Iron probed with XFEL
Time: 2:30 - 3:30 PM, Friday, June 23, 2017
Place: Conference Room 410, HPSTAR (Shanghai)
Host: Dr. Toshimori Sekine
Abstract
Understanding of the physics under shock compression has been an important subject over the past century. Many experimental results have revealed that the shock-compressed material initially behaves as a purely elastic medium, and finally results in plastic deformation. However, the details of the transition between these two states has not been fully understood. We directly observed transient structural dynamics of iron induced by shock wave using X-ray Free Electron Laser (XFEL) pulses with a duration of 10 femtoseconds. We found that the shock at an early stage produces an elastic strain corresponding to a stress of 22 GPa. We suggest that the giant elasticity induces generation of dislocations causing a high density of lattice defects inside the material, and that the plastic deformation without dislocations occurs, which was theoretically predicted but has not been observed.
Biography of the Speaker:
Dr. T. Sano received his B.S. and M.S. in precision engineering from Kyoto University and his Ph.D. from Osaka University.
Currently an associate professor in Division of Materials and Manufacturing, Science of Osaka University. His principal research interests lie in both fundamental and practical studies of laser-matter interactions.