HIGH ENEGY DENSITY
LABORATORY ASTROPHYSICS
An Interdisciplinary Program at the
University of Rochester

Department of Physics and Astronomy
The Laboratory for Laser Energetics

1. Intro
2. People
3. Research

The use of high energy density devices like Inertial Confinement Fusion (ICF) lasers for investigations of cosmic environments is a new development in astrophysics which holds great promise.  It represents a fundamentally novel approach to astronomy, which has always been an observational, not an experimental science.  Astronomical researchers have always had to take whatever photons they could catch with their telescopes and hope these could serve as proper diagnostics of the distant objects under study.  Few controls on the investigations have been possible.  The capacity to bring controlled experiments to bear on issues of high energy density astrophysical plasmas is exciting because it would allow an unprecedented level of contact between theory.   The development of astrophysics with intense lasers also holds the promise of developing a stronger and mutually beneficial relationship between the astrophysical and plasma physics communities.  The plasma physics utilized in many astrophysical studies is often too simplified and modern plasma methods have yet to find widespread acceptance in the practice of astrophysics.

The theoretical astrophysics group in the Department of Physics and Astronomy and Laboratory for Laser Enegetics (LLE) have combined their resources and talents to create aa new program in High Energy Density Laboratory Astrophysics.  The LLE,housing the most powerful laser in the world, provides a new tool for attacking a variety of astrophysical problems, both experimentally and theoretically.  Increased collaborations between astrophysicsts and plasma scientists are essential for progress in this new field and together UR astrophysicists and LLE scientists are pushing the frontiers of recreating the Univerese's most exotic phenomena.

The program encourages the participation of graduate students who can recieve training in a variety of fields including high performance computational physics/astrophysics, theoretical plasma/astrophysics, experimental plasma physics, intense laser physics.  A listing of graduate physics courses including astrophysics and plasma physics couses may be found at the Department's webpage (need link here).


Program Participants
 
 
Faculty

Eric Blackman (Astrophysics)
Riccardo Betti (ME, Physics)
Adam Frank (Astrophysics)
Larry Helfer (Astrophysics)
David Meyerhofer (ME, Physics)
Robert McCory (ME, Physics)
Jack Thomas (ME, Astrophysics)
Hugh Van Horn (NSF, Physics)
 

 Research Faculty

Tim Collins (LLE)
Steve Craxton (LLE)
Igor Igumenshcev (LLE)
James Knauer (LLE)
Patrick McKenty (LLE)
Stan Skupsky (LLE)
 
 

 

 Grad Students and Post-Docs

Grad Students
Andrew Cunningham
Alexei Polundenko
Stephanie Sublett

Post-docs
Tom Gardiner
Vladimir Pariev


Current projects in High Energy Density Laboratory Astrophysics

Pulsed Astrophysical Outflows: Many astrophysical objects show pulsed figure-8 shaped lobes of gas being driven into space at hypersonic speeds.  The origin and nature of these outflows remains unclear.  Current experiments underway are aimed at studying the physics of multiple colliding shocks which form as the central source (i.e. a dying Sun-like star) repeatetly ejects high velocity streams of matter.
 
Hubble Space Telescope image of bipolar outflow from a dying Sun-like star.  Note the narrow lobes. Material in these kinds of outflows can travel at more than 100 km/s. Note interior strutures indicating mutiple mass ejections.

First results of experiment designed to create scaled version of hypersonic outflows. A conical plug (top) is compressed by laser and squeezed through central hole.  Using this configuration we can study mutiple outflows.

 

Hypersonic Jets: Narrow beams of plasma are observed traveling away from a variety of astrophysical sources.  Experiments in collaboration with Imperial College in London are creating scaled version of these flows which travel with speeds of more than 200 kilometers per second.
 
 
Hypersonic Jet from young solar-type star.  Note how narrow the plasma beam remains as it propagates from the star.

Experimental recreation of hypersonic radiative jet created with a 16-wire Z-pinch (experiments performed at Imperial College).  The jet created has speeds of over 200 km/s just as the real young stellar object jet.

Clumpy Astrophysical Flows: Shock waves from supernova blasts sweep through an interstellar medium thta is usually highly inhomogenous or "clumpy".  Inspite of this fact few studies of clumpy flows have been possible because of the non-linearity of the physics.  Experiments are underway to study the evolution of multiple clumps being overrun by strong shock.
 

Adaptive Mesh Simulations of Clumpy Outflows.
Red lines mark regions of increased resolution.  Succesive figures show zooming onto individual clump features.


 
 

Experimental arrangement for muliple clump-shock interaction experiments.  Experiments are underway using both the Omega laser system and a Z-pinch with P. Drake (UMich) .