MSE Seminar Series: Rhonda Stroud
Friday, February 19, 2010
Room 2108 Chemical and Nuclear Engineering Bldg.
Nanoastronomy: Laboratory Analysis of Extraterrestrial Materials
Presented by Rhonda Stroud
Naval Research Laboroatory (NRL)
Traditional astronomy relies on remote observations using sophisticated instrumentation to probe objects on the scale of whole stars. Nanoastronomy, conversely, relies on direct, laboratory-based observation of micron-to-nanometer sized particles formed in stars or other cosmic environments. Samples range from agglomerated SiC nanoparticles formed in supernovae to hollow organic nanoglobules formed at the dawn of our solar system, each preserved in asteroids or comets. Because the laws of physics and chemistry are the same for nanoparticles formed in a laboratory vacuum chamber as those formed in the outflows of a supernovae, analyses of the elemental chemistry, crystal and microstructures of extraterrestrial particles provide insight into their formation conditions. Using techniques such as focused ion beam microscopy (FIB), transmission electron microscopy (TEM), secondary ion mass spectrometry (SIMS) and synchrotron-based scanning transmission x-ray microscopy (STXM), we can determine where and how individual nanoparticles formed. This information provides unique constraints on the astrophysical processes that shaped our solar system, complementary to that obtained by traditional, telescope-based astronomy.
About the Speaker:
Dr. Stroud holds a B.A. in Physics from Cornell and a Ph.D. in physics from Washington University, St. Louis. She has been been at the Naval Research Laboratory since 1996, and has served as head of the nanoscale materials section for the last 3 years.
Dr. Stroud was made a fellow of the American Physical Society last November. Her research specialty is the application of TEM to nanoscale materials ranging from thin film electronics and fuel cell catalysts, to dust particles that condense around stars older than the sun.