🚀 go-pugleaf

>> ...  Word has it that the
>> Nova, Novette inertial confinement scheme at Larry Labs is a loser and
>> only good for bomb work.  It'll never be useful for producing electrical
>> power or propelling a spacecraft.

In article <7245@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes:
>Laser fusion has never looked particularly good for propelling spacecraft;
>lasers are too inefficient and too heavy.  This is why the Daedalus study
>picked electron-beam fusion instead.

That choice was made some time ago, and now it seems that light
ion beam fusion looks more promising.. . but,  still doubtful.  
Although (assuming every thing works) the size reduction would be 
very significant from laser to light ion fusion devices, the size 
is still too large to be viable for boost phase or "planetary"
work.  

The "Spheromak" is about the right size and is simple enough to
consider for use as a source for fusion driven propulsion, but it
has serious engineering problems due to the need for a "tightly
fitting" conducting shell.  This shell is solid in Spheromaks,
and tends to be vaporized by the dense adjacent fusion plasma.

The PLASMAK(TM) uses a plasma shell and surrounding high pressure
gas blanket as the "wall", and gets much better conductivity by
setting up with energetic electron currents.  Because it can be
compression heated, it can burn protium boron eleven to three
helium nucleii, and that means no radiation problems.  The
recirculated liquid density gas blanket is plasmatized by the 
fusion energy and that in turn either drives an inductive MHD 
electric power generator at 60 hertz, OR it could be expanded 
directly to generate boost thrust for lift phase applications,
during planetary landings/lift-offs. 

Since these plasmoids are formed by direct or inductive electric
discharge in the fusion fuels, and the compression heating is 
ideally efficient, the resulting engines will be very compact
in size.  Averarge power would be on the order of 10 gigawatts.

In propulsion applications thrust would vary greatly depending
on available mass reserves.  
+---------------------------------------------------------+--------+
| Paul M. Koloc, President: (301) 445-1075                | FUSION |
| Prometheus II, Ltd.; College Park, MD 20740-0222        |  this  |
| {umcp-cs | seismo}!prometheus!pmk; pmk@prometheus.UUCP  | decade |
+---------------------------------------------------------+--------+