Overview
We do experiments that simulate astrophysical systems, to explore physical mechanisms that matter in astrophysics. To do this, we use lasers (and an efficient source of x-rays called a Z pinch) to produce temperatures of order a million degrees in volumes of cubic millimeters. We do a variety of work in our laboratory related to the experiments. We improve the instrumentation used to measure structures on the scale of microns and nanoseconds. We build the targets for the experiments. We use computers to simulate the hydrodynamic behavior of laser-driven experiments and supernova explosions. We analyze data from the experiments. We also work in other areas, mentioned below.
Lasers are an incredibly-powerful research tool. Throughout much of science today, they are used for diagnosis of physical systems. In the Drake Research Group we go beyond this, using very powerful lasers to create a tailored physical environment in which to ask a specific physical question. We do this by ionizing matter in a specifically-designed way, with a well-chosen geometry and other controlled parameters, so as to produce a plasma (ionized matter) which has the properties we desire. We also do similar work using "Z", a z-pinch at the Sandia National Laboratories, as an energy source.
Our primary emphasis at present is the study of mechanisms that produce structure in supernovae and supernova remnants. The blast wave, which blows apart the star, and the shock wave, which the explosion drives out through the universe, drive instabilities that contribute to the marvelous structures now being revealed by observatories such as the Hubble and Chandra. The figure above illustrates one of our experiments, designed to simulated the structures now developing in SN1987A. The arrow on the left shows the first bright spot produced by the collision of the ejecta from the star and the pre-existing circumstellar ring. ( The image of SN 1987A is from the Hubble Space Telescope. It was created with support to the Space Telescope Science Institute, operated by the Association of Universities for Research in Astronomy, Inc., from NASA contract NAS5-26555, and is reproduced with permission from AURA/STScI.)
State-of-the-art computer models can simulate the behavior of shock waves that produce pressures above a trillion atmospheres and supernova remnants many light years in extent. We apply these models to both laboratory studies such as hydrodynamics at high energy density and to astrophysical systems.
Our group also participates in other research. Michigan is a delightfully interdisciplinary place. We are involved in the development of improved plasma thrusters for satellite maneuvering, where we use laser scattering to probe the particles they emit. We do theory aimed at understanding the acceleration of the solar wind. We also collaborate in experiments and theory that probe the phenomena that occur when very intense lasers produce relativistic plasma motions.
Since 99% of the universe we can see is plasma, there are many scientific questions and many physical systems we can address with such tools. We work with a variety of laboratories at Michigan and elsewhere. We devise experiments, run simulations, carry out experiments, analyze data, develop instrumentation, and do related theory. For more information visit the links on the homepage or contact: Professor Paul Drake at rpdrake@umich.edu.