RE: Fusion

I believe that Q > 50 would have to be harnessed energy, not just
produced
energy. 

How will fusion work in the game future history?

Is it a sustained fusing of one or a few atoms at a time over a long
period?

Is it periodic fusing of a larger number of atoms, collecting and
storing
the energy?

Either method has difficulties.

Sustained fusion would have to extremely protected both from direct hits
and
from being jostled. It may also have excessive heat and/or gas/vapor
discharges. And if you are not using all the energy each moment, it will
be
wasted. 

Periodic fusion would have to spend a good amount of space on batteries.
It
may also take a somewhat substantial "charging" time (once a day?). It
may
be as vulnerable to being jostled, but would not fall out of the sky,
because of a reactor failsafe.

Of course, you could have a blending of both, a sustained fusion that
stores
the energy during low demand for high demand situations. However, you
then
also get the weaknesses of both (more mass spent for batteries and to
protect the fusion reactor).

Larger fusion reactors, would probably be a blending of both, as they
have
more room to deal with byproducts (heat, gas), have more shielding, and
be
better protected.

But, again, when dealing with a universe with FTL and antigrav, you
_must_
have the ability to stretch credibility. So you may have the walnut size
ion
drive, if you so wish.

I prefer some limitations on the fusion reactor to give a reason to take
the
fuel cell or internal combustion engines. Otherwise, as soon as you
reach
the fusion engine, your armor forces will be able to take anything else
(no
weapon limitations, little logistics train, etc.) This is also why I
assumed
that powerarmor used fuel cells rather than microfusion powerplants.
And, of
course, I also like the idea that fusion plants would be quite finicky,
requiring increased maintenance.

-----
Brian Bell
-----

Tony said:
they are looking for Q > 50. So far, the tokamak design has reached the
highest Q. The current problem is that plasma instabilities quickly halt
the fusion process. Very recently, computer models have shown that it
may be possible lengthen the stable regime through magnetic field
feedback. Basically, as instabilities occur, the confinement field is