1. Department of Materials Science and Engineering, University of California Davis 1 , Davis, California 95616, USA
2. Department of Geophysics, Stanford University 2 , 397 Panama Mall, Stanford, California 94305, USA
3. Department of Geological Sciences, Stanford University 3 , 450 Jane Stanford Way, Bldg. 320 Rm. 118, Stanford, California 94305, USA
4. Department of Physics and Astronomy, University of Rochester 4 , 206 Bausch and Lomb Hall, Rochester, New York 14627-0171, USA
5. SLAC National Accelerator Laboratory 5 , 2575 Sand Hill Road, Menlo Park, California 94025, USA
6. Department of Earth and Planetary Sciences, University of California 6 , Davis, California 95616, USA
7. Laboratory for Laser Energetics 7 , 250 E. River Rd., Rochester, New York 14623, USA