[Sci-all-l] Distinguished Lecturer to speak Monday @ 4:00, Physics and Astronomy

[James Lombardi]

This should be a great talk. ---Jamie

                      Physics and Astronomy Colloquium
                      ================================
                          Monday, November 8 2004

                 "Self-Organization in Magnetized Plasmas"

                               Michael Brown
                            Swarthmore College
              American Physical Society Distinguished Lecturer

                      Physics Lecture Hall (Room 207)
                         Sanders Physics Laboratory
                               Vassar College

            Tea and Cookies at 3:45, Lecture begins at 4:00 PM

It is a common process in the universe for plasma and magnetic fields to evolve
together in a turbulent way but then rapidly relax to simple, self-organized
structures.  Solar flares erupt from the photosphere tangled and chaotic, but
via a process called magnetic reconnection, they relax and straighten.  This
process releases energy in the form of superheated plasma and rapidly flowing
jets.  On a much larger scale (millions of light years), galactic disks
collapse, rapidly shedding angular momentum and in the process generate
extended, magnetized jets along their axes.  On human scales, laboratory
experiments are underway seeking self-organized magnetic structures that would
be suitable "bottles" for a fusion reactor.

We present recent experimental results from the merger of two rings of hot,
magnetized plasma in the Swarthmore Spheromak Experiment (SSX).  During the
merging process, the plasma self-organizes to generate single, large scale (r =
0.2 m, L = 0.6 m), three-dimensional magnetic structure called a field-reversed
configuration (FRC).  The rate at which the merging proceeds is governed locally
by magnetic reconnection in which magnetic fields associated with each ring
become shared.  The magnetic reconnection rate is fast and fully
three-dimensional.  Magnetic reconnection converts magnetic energy to heat (up
to Te ~ 10^6 K), energetic particles (Ei > 100 eV), and flow (up to 100 km/s).

Further information can be found at
http://plasma.physics.swarthmore.edu/selforg/index.html.


*********************************************************************
  James Lombardi                               Phone:  (845) 437-7081
  Assistant Professor of Physics                 Fax:  (845) 437-5995
  Department of Physics and Astronomy
  Vassar College
  124 Raymond Ave.
  Mail Drop 562
  Poughkeepsie, NY 12604-0562    http://faculty.vassar.edu/lombardi/
*********************************************************************