Roger Falcone is a professor of physics at the University of California, Berkeley, and an affiliated faculty member of Berkeley's Energy and Resources Group and Applied Science and Technology Program. He chaired the Physics Department from 1995-2000. As of January 2018 he is a Professor of the Graduate School at Berkeley. He received his A.B. in Physics (1974) from Princeton, and Ph.D. in Electrical Engineering (1979) from Stanford, and was the Marvin Chodorow Fellow in Applied Physics (1980-83) at Stanford. He was the Director of the Advanced Light Source x-ray synchrotron facility at Lawrence Berkeley National Lab (2006-2017) and was President of the American Physical Society (2018).
Research Interests
Our research group studies the dynamics of ultrafast processes in atoms, molecules, solids, and plasmas. We develop advanced technologies (pulsed sources of x-rays, high-speed x-ray detectors, and novel techniques), and we perform experiments at major facilities in the Bay Area and around the world. Currently, we are focusing on understanding the behavior of solids and plasmas that are under extreme conditions of pressure and temperature. We are studying how these materials respond to high stress (up to a billion atmospheres of pressure, or 1 GigaBar) and high temperatures (several million degrees, or hundreds of eV). We measure and control dynamics on the length and time scales of atomic motion (down to nanometers and femtoseconds). A particular area of interest is the “equation of state” of high energy density matter, which means understanding the relationship of pressure, density, and temperature under extreme conditions. Also important are electronic, structural, and thermodynamic properties, such as the relative amount of ionization, the local order, and the thermal conductivity in such matter.
The questions we address are generally fundamental, since we are extending science into novel regimes. The applications of our work range from geophysics (what is the chemistry of materials under pressure?), to materials performance (can we design materials that will perform under extreme conditions?), to fusion energy (can we create plasmas at high enough density and temperature to undergo nuclear burn?), to astrophysics (can we understand the physics of giant planets and stars?).
In a separate area of research, we are helping develop novel methods of high-resolution, chemically-resolved, ultrafast, three-dimensional imaging at the nanoscale, using x-rays, in order to better understand the physics and chemistry of functional materials under more conventional conditions.
Our tools involve advanced x-ray synchrotrons, the world’s highest energy lasers, free-electron x-ray lasers, and tabletop, ultrashort pulse lasers. Our team includes faculty and other scientists from many countries, theorists and experimentalists, as well as postdoctoral, graduate, and undergraduate students.
Publications
(Selected)
1. M.J. MacDonald, et al, "The colliding planar shocks platform to study warm dense matter at the National Ignition Facility," Physics of Plasmas 30, 062701 (2023). https://doi.org/10.1063/5.0146624
2. D. Kraus, et al, "Indirect evidence for elemental hydrogen in laser-compressed hydrocarbons," Phys. Rev. Research 5, L022023 (2023) DOI: 10.1103/PhysRevResearch.5.L022023
3. T. Döppner, et al, "Observing the onset of pressure-driven K-shell delocalisation," Nature 618, 270–275 (2023). https://doi.org/10.1038/s41586-023-05996-8
4. Vanessa Schoeppler, et al, "Soft X-ray linear dichroic ptychography: The study of crystal orientation in biominerals," Proceedings Volume 11839, X-Ray Nanoimaging: Instruments and Methods V; 118390D (2021) https://doi.org/10.1117/12.2594172
5. J. Lutgert, et al, "Structural properties of shock-compressed polyethylene terephthalate," Scientific Reports, (2021) 11:12883 https://doi.org/10.1038/s41598-021-91769-0
6. Joint Committee on Ballistic Missile Defense in the Context of Strategic Stability; Committee on International Security and Arms Control; Policy and Global Affairs; National Academy of Sciences; Russian Academy of Sciences, "Regional Ballistic Missile Defense in the Context of Strategic Stability," National Academy of Sciences, Washington, DC (2021) https://doi.org/10.17226/24964
7. Yuan Hung Lo, et al, "X-ray linear dichroic ptychography," Proceedings of the National Academy of Sciences, January 19, 2021, 118 (3) e2019068118; https://doi.org/10.1073/pnas.2019068118
8. LaForge, Aaron, et al, “Time-resolved quantum beats in the fluorescence of helium resonantly excited by XUV radiation," J. Phys. B: At. Mol. Opt. Phys. 53 244012 (2020) https://doi.org/10.1088/1361-6455/abc660
9. Andrea L. Kritcher, et al, "A measurement of the equation of state of carbon envelopes of white dwarfs," Nature 584, 51–54 (2020) https://doi.org/10.1038/s41586-020-2535-y
10. S. Frydrych, J. Vorberger, et al, "Demonstration of X-ray Thomson scattering as diagnostics for miscibility in warm dense matter," Nature Communications 11, 2620 (2020) https://doi.org/10.1038/s41467-020-16426-y
11. Roger Falcone, et al, "Workshop Report: Brightest Light Initiative (March 27-29 2019, Washington, D.C.)" https://arxiv.org/pdf/2002.09712.pdf
12. Yuan Hung Lo, et al, "Multimodal x-ray and electron microscopy of the Allende meteorite," Science Advances, 20, eaax3009 (2019) DOI:10.1126/sciadv.aax3009 (2019)
13. N. J. Hartley, et al, “Evidence for Crystalline Structure in Dynamically-Compressed Polystyrene up to 200 GPa,” Sci Rep 9, 4196 (2019) https://doi.org/10.1038/s41598-019-40782-5
14. Travis D. Frazer, et al, "Engineering Nanoscale Thermal Transport: Size- and Spacing-Dependent Cooling of Nanostructures," Phys. Rev. Applied 11, 024042 (2019) https//:doi.org:/10.1103/PhysRevApplied.11.024042
15. N. J. Hartley, et al, “Liquid Structure of Shock-Compressed Hydrocarbons at Megabar Pressures,” Phys. Rev. Lett. 121, 245501 (2018)
16. D. T. Bishel, et al, “Using time-resolved penumbral imaging to measure low hot spot x-ray emission signals from capsule implosions at the NIF,” Rev. Sci. Inst. 89, 10G111 (2018) https://doi.org/10.1063/1.5037073
17. T. Doppner, et al, “Absolute Equation-of-State Measurement for Polystyrene from 25-60 Mbar Using a Spherically Converging Shock Wave,” Phys. Rev. Lett. 121, 025001 (2018) https://doi.org/10.1103/PhysRevLett.121.025001
18. D. Kraus, et al, “Formation of diamonds in laser-compressed hydrocarbons at planetary interior conditions,” Nature Astronomy 1, 606–611 (2017) doi:10.1038/s41550-017-0219-9