Secret of Fragmentation Nuclaer Rocket Thrust

[Frank Robertson]

In previous reading about fragmentation nuclear rockets for high speed
exploration of the solar system, I read that fragments of the
fissioning core are used as propellant, accelerated by magnetic
fields. I was wondering how the energy of a fissioning fragment
translated to thrust. Apparently, the answer is that some fragments
are traveling at 3 - 5% the speed of light from the get-go. Yeah! Now
there's some high speed propellant!

"We propose an innovative nuclear power generation system design using
dusty radioac-
tive (¯ssile or not) material plasma as a fuel. The ¯ssion fragments
or decay products
accelerated during the disintegration process to velocities of 3{5% of
the speed of light are
trapped and collected in a simple combination of electric and magnetic
¯elds resulting in
a highly e±cient (90%), non-Carnot, DC power supply. In a conventional
nuclear reactor
this high kinetic energy of the ¯ssion fragments is dissipated by
collisions to generate heat,
which is converted to electrical power with e±ciencies of no more than
50%. Alterna-
tively, the ¯ssion fragments produced in our dusty plasma reactor can
be used directly for
providing thrust. The highly directional ¯ssion fragment exhaust can
produce a speci¯c
impulse of one million seconds resulting in burnout velocities several
thousand times those
attainable today. Previous concepts su®ered from impractical or
inadequate methods to
cool the ¯ssion fuel. In this work the heating problem is overcome by
dividing the solid fuel
into small dust particles and thereby increasing the surface to volume
ratio of the fuel. The
small size of the fuel particle allows adequate cooling to occur by
the emission of thermal
radiation.
I"

from
http://docs.google.com/viewer?a=v&q=cache:2YBpKaAFA4AJ:www.rbsp.info/rbs/RbS/PDF/aiaa05.pdf+fission+fragmentation+rocket+convert+propulsion+thrust&hl=en&gl=us&pid=bl&srcid=ADGEESiUoBge9B7CdQ96SQHau9gMMnu0upBiGQotgN53Ct6gIgH7fh3bFQUSREMR7qDO6PuAS9jAu9CYCn7GSQRNcKMY8Ae_b7PFRuHT72ifjRW7mohmHBm0n64DKpfKMzKrq1DwTpGR&sig=AHIEtbRDfAo8q8_I4lWOUXdg923e0Q0RPg