Re: Fusion energy

Donald Hosford schrieb:
> Just one question...(no I am not questioning anyone's 
> logic here..) 
> 
> I love the idea of fusion also.  But I have a hard time 
> getting any info that relates to games...ie: how long will
> the fuel last, how big a typical reactor would be, ect...

There are several paths towards building a fusion reactor that are 
being explored. The two that look most promising are plasma confinement 
and Laser Implosion fusion. And all use the Deuterium isotope of 
Hydrogen instead of plain Hydrogen, because Deuterium is easier to fuse 
that hydrogen.	

For plasma confinement, Deuterium gas is heated to extremely high 
temperatures and compressed by electromagnetic fields to a high 
pressure to simulate conditions inside a star. 

For Laser implusion fusion, you take a small hydrogen pellet and hit it 
from all sides with Laser beams. The pellet implodes to produce a 
micro-hydrogen-bomb. 

None of the methods being explored has, AFAIK yet achieved energy 
break-even. That is, there have been fusion reactions, but so few that 
the energy pumped in far heating etc. has been rather higher than the 
energy from the reactions. 

Even if this is achieved and you produce a worthwhile amount of fusion 
reactions, there reamin the ddevelopment problem of converting this to 
energy at commercially viable rates. 

Early fusion plants will probably be about as big as a present-day 
power station. The fusion reactor itself probably about he size of a 
small house, but there will be generators and all the associated 
equipment. 

It will be a long time before we get it down to the size of an AFV 
engine. But that what PSB is for :-) 
 
> At our current stage of fusion development, how did they 
> (the science boys) figure a little hydrogen will go a long way?

Because the basic fusion reactions have been well studied in nuclear 
accelerator experiments. You shoot protons (Hydrogen atoms' nuclei) at 
liquid hydrogen targets and observe the results. So we know pretty well 
at which speeds hydrogen will fuse and what kind of energy and 
particles will get out. From this and the laws of thermodynamics, it is 
fairly easy to calculate the energy output of a hydrogen cloud under 
any conditions. 

Unfortunately, the accelerator method doesn't scale well to produce 
worthwhile amounts of energy (thouhg I think there have been 
experiments in that direction). 

> In the RPG GURPS Space, they include a fusion reactor for 
> players ships, which "takes no fuel...internal fuel supply lasts 200 
years."   
> When I read this, I thought Steve Jackson had blown a gasket...didn't 
seem  
> real. 

Seems reasonable (see our earlier discussion) for a power supply. It 
will depend a lot on what the energy is used for. If you use the energy 
to accelerate the ship to high speeds (near lightspeed) that will eat a 
lot of energy. But there would be a lot of assumptions and calculations 
to do to get hard numbers. 

> After reading Traveller, where the smallest fusion reactor takes 20 
> tons (liquid) hydrogen fuel to move a 100 ton ship (displacement) 1 
parsec	
> in a week... 
> 
> I quess my question is this: Is this a real possibility?  
> No foolin? 

1 parsec = 3.26 light years 
Hence, that ship is moving at faster-than-light speeds. 
That should answer the "real possibility" question.

> If so, that would be super cool!  8-D

Indeed.

Greetings