High Energy Density Plasmas and Laser-Plasma Physics
The study of laboratory and astrophysical plasmas is currently in the midst of a renaissance. In astrophysics, new observations and computational techniques have revealed the ubiquity of non-linear plasma processes in environments as diverse as star-forming regions and the environments surrounding black holes. To properly account for the life-cycle of stars and galaxies, one must understand the origin and behavior of the magnetic fields that play a critical role in nearly all astrophysical flows.
In the laboratory, the current generation of high-power lasers has opened a new window into high-energy-density plasma environments. Energy densities in excess of 1012ergs/cm3, such as exist in the core of stars, are now accessible to laboratory studies. With the advent of the next generation of super lasers, controlled thermonuclear ignition has finally come within reach. Ignition will be attained by inertial confinement (ICF) of a hot dense plasma compressed by the super lasers over an interval of a few nanoseconds.
With the construction of the National Ignition Facility, a $1.5 billion, 1.8-MJ laser at the Lawrence Livermore National Laboratory, the field of high-energy-density physics (HEDP) and ICF will be among the leading research areas in physics. The University of Rochester, with its 60-beam, 30-kJ OMEGA laser system housed in the Laboratory for Laser Energetics (LLE), is the world's leading academic institution in the field.
The Omega system gives the University unique access to high energy density plasma environments, which no other university can offer. Current research in ICF involves laser-plasma interactions (Professor Froula), hydrodynamic and plasma stability (Professor Betti, Professor McCrory) and theoretical plasma physics (Professor Jason Myatt).
In astrophysical plasma studies ongoing projects involve computational hydrodynamics and magneto-gasdynamics (Professor Frank), dynamo theory and two-temperature plasmas (Professor Blackman) and solar magnetohydrodynamics, solar dynamo theory, and the physics of sunspots (Professor Thomas). The group is also interested in issues centered on radiation hydrodynamics, plasma turbulence and ambipolar diffusion.
A new program in High Energy Density Laboratory Astrophysics makes use of Inertial Confinement Fusion (ICF) lasers for investigations of cosmic environments. Increased collaborations between astrophysicists and plasma scientists are essential for progress in this new field and together UR astro/plasma physicists and LLE scientists are pushing the frontiers of recreating the Universe's most exotic phenomena (Professor Collins, Professor Rygg).
Using pulsed systems (principally lasers and pulsed-power generators) to study the properties of matter under extreme conditions, Professor Gourdain's extreme state physics research group focuses on exploring the fundamental laws of strongly interacting systems, studying the formation of flows and shocks under extreme conditions and validating competing physical models by comparing numerical simuations to experimental measurements.
Modern high-power lasers are becoming also a tool to test fundamental theories like Quantum Electrodynamics (QED) because of the ultra-high intensities they are capable to deliver. Charged particles, like electrons and positrons, driven by such high fields undergo violent accelerations, their motion becomes highly nonlinear, and radiate large amounts of high-energy, gamma-ray photons. In turn, photons can decay into electron-positron pairs when interacting with sufficiently high-intensity laser fields. Such nonlinear sector of QED is still relatively unexplored experimentally as it is inaccessible to conventional high-energy colliders. The activities of the group of Professor Di Piazza focus on analyzing theoretically the new possibilities offered by ultra-high intensity lasers, like the under-design facility EP-OPAL at the LLE, to test the behavior of matter, light, and even of the vacuum in the presence of strong background electromagnetic fields.
The plasma physics program is closely aligned with a larger University interdisciplinary program in high energy density plasma physics, involving additional faculty at both the LLE and the Department of Mechanical Engineering. Student applicants to the department who are interested in this area of research, should make specific mention of their interest in this program on their application form.
Plasma and Laser Physics Links
Center for Matter at Atomic Pressures
The Center for Matter at Atomic Pressures (CMAP) is a new National Science Foundation (NSF) Physics Frontier Center funded with $12.96 million from the NSF. CMAP is hosted at the University of Rochester in collaboration with researchers at MIT, Princeton, the Universities of California at Berkeley and Davis, the University of Buffalo, and the Lawrence Livermore National Laboratory. Research at CMAP will focus on understanding the physics and astrophysical implications of matter under pressures so high that the structure of individual atoms is disrupted. Visit the CMAP website to learn more.