On Wed, Feb 24, 2016 at 03:36:56AM -0500, Richard Aiken wrote:
> Of course, this leads: "Well, if LH is necessarily pure fuel, then what is
> unrefined fuel?"
>
> The answer (at least IMTU) is, "Water."

The answer IMTU is that refined fuel is isotopically pure H2 with
essentially no neutrons anywhere in it.

Unrefined fuel in the context of buying fuel for a starship refers to
anything else that contains large amounts of hydrogen, from chemically
pure hydrogen with the usual slight amounts of deuterium, through
fresh water, cometary ices, liquefied gas giant atmosphere, or crude
oil.  Fuel refiners vary in their ability to process the more exotic
forms of unrefined fuel, but essentially all of them can handle fresh
water.

The fuel IMTU is turned to plasma in the process of being used in a
jump drive, and all drive feeds do have processes for getting rid of
most impurities.  Some traces of non-hydrogen elements and almost all
of the deuterium will get through though, and make the jump rather
rougher (both physically and in exit precision) than feeding it
refined fuel.  Legends of pirate captains who boil down the bodies of
victims to mix in with jump fuel feedstocks remain completely
unconfirmed.

- Tim