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Inertial Confinement Fusion

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Astrophysical objects (solar flares to galactic jets) ... ( curl of Ohm): Astrophysical Plasma Review. ramifications of MHD. Astrophysical Plasma Review ... – PowerPoint PPT presentation

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Title: Inertial Confinement Fusion


1
National Undergraduate Fellowship Program
in Plasma Physics and Fusion Engineering Plasma
Astrophysics Michael Brown Swarthmore
College June 2007 Outline Brief plasma review
(B-fields and MHD) Two important
paradigms Astrophysical objects (solar flares to
galactic jets) Astrophysical processes (dynamos,
reconnection and pulsars)
2
Astrophysical Plasma Review
  • Magnetic fields
  • related to electric fields by Lorentz
    transformation
  • Q why are there large scale B-fields but no
    large scale E-fields in the universe?
  • A ...there are lots of electric monopoles
    around to short out electric fields
  • B-fields are associated with currents but do
    currents cause B-fields are vice-versa?
  • exert forces on currents ForceJxB
  • contain energy

3
Astrophysical Plasma Review
equations of MHD
Newton II
Ohms Law
Maxwells eqs
induction eq. (curl of Ohm)
4
Astrophysical Plasma Review
ramifications of MHD
5
Astrophysical Plasma Review
  • Frozen-in Flux
  • high conductivity Coulomb collisionality drops
    with T (so ? T-3/2)
  • universe is an excellent conductor of electricity
    almost everywhere
  • frozen-in flux
  • assume perfectly conducting magnetofluid
  • no electric field in a perfect conductor
  • if field lines move with respect to fluid then
    an electric field is induced
  • therefore fields move with the fluid!

6
Poynting Vector
7
Simple 2D Reconnection Theory (Sweet/Parker)
8
Reconnection Rate
where Rm is based on the Alfven velocity in the
bulk magnetofluid and on the largest scale of the
system L. Malf is a dimensionless measure of the
reconnection rate or the rate at which magnetic
field lines are annihilated or the direct
electric field. More sophisticated models
Petschek, 1964 and Vasyliunas, 1975 predict a
faster reconnection rate and a smaller ration of
uout/uin. It appears, however that a bound
exists
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