Parmasson,
Ah! A question right up my alley!
Piper gave you some excellent links, really good stuff there. Let me blather some about shielding then.
Most(1) fusion reactions are going to produce a lot of neutrons, up to two orders of magnitude more than the various fission reactions we currently use for power generation. That amount of neutrons is going to play merry hell with equipment AND personnel. Let's discuss equipment first.
On an atomic level, you can envision metals and other substances like a giant 3D tinkertoy of sorts. There are various round bits held together by rods to make a structure, just like in a molecule there are atoms 'held' together by shared electrons to form a lattice. So, picture a cube 10m x 10m x 10m made up of tinkertoys, then start shooting a lot of bullets at it.
Some of the bullets are going to pass through without hitting anything. Some of the bullets are going to hit the rods, but in our cube they magically grow back. Some of the bullets are going to hit the round bits the rods connect together. That last bit is our problem.
If we hit enough of those round bits, our 10m cube will weaken and maybe even fall apart and, if we fire enough bullets, we'll eventually hit enough round bits. It's just a matter of time.
Next, shift your mental gears a bit. The tinkertoy round bits are now atoms and the cube is a sheet of metal. If we 'fire' enough neutrons at that sheet, we'll do two things to it. First, we'll 'irradiate' it. We'll cause the atoms in it to change, even become radioactive themselves. Fusion test fixtures usually became very radioactive even after a single runs.
Second, we'll 'embrittle' the metal. We'll 'knock' so many atoms out of the metal's internal lattice that the metal will become weak. Neutron embrittlement is the primary reason why several US fission reactors have been shutdown. After a few decades exposed to a much lower lesser neutron flux, the metals making up the reactors have been weakened to a point where they are no longer safe to operate.
So, we've 'irradiated' and 'embrittled' our fusion bottle. What's going to happen to our crew?
As Piper wrote, hydrogen is a good shield materials for neutrons. It has to do with a hydrogen atom's size. Time to imagine again...
Picture a bowling ball, a billiard ball, and a golf ball all on a pool table. We're going to shoot the cue ball dead on at all three in turn. In which collision do you think the greatest transfer of energy will take place?
Well, when the cue ball hits the bowling ball it will bounce off and the bowling ball will hardly move. Little energy transfer there.
When we hit the golf ball, the golf ball will shoot away but the cue will keep moving quickly too. Again, little energy transfered.
However, when we hit the billiard ball - a ball that is the
same size as our cue ball - what happens? The billiard ball will move off while the cue slows substantally.
That's just what happens when a neutron hits the nucleus of a hydrogen atom.
So materials with lots of hydrogen atoms; otherwise called hydrogenous materials, give us lots of hydrogen nucleii for neutrons to hit and subsequently be slowed or 'moderated'. Hit enogh hydrogen nucleii and they'll be absorbed or 'stopped'. Sometimes a hit will 'reflet' a neutron back to where it came from!
By the way, your
body is a hydrogenous material. Lots of fats, lots of water, lots of hydrogen. Ooops!
Shielding, even with hydrogenous materials, depends a great deal on density. Hydrogen is a great neutron shield, but hydrogen gas isn't exactly dense is it? You players may better off flooding that stateroom with water, if they have enough. Rigging some sort of chiller that would 'allow' their hydrogen fuel to remain a liquid or gaseous slurry might be an idea.
I'm not familiar with T20's scout deckplans, but all the other varieties of Suleiman have a transverse passageway between engineering and the ship's common area. Now, IF your players could flood that passageway with a deliberate fuel 'spill' and IF the bulkheads hold and IF the hydrogen stays dense enough/doens't wamr up too much, then they MAY reach the starport.
Of course the clean-up and repairs are going to be horrific. Cryo problems from the fuel, irradiated materials, all sorts of nastiness. Instead of attempting any repairs, the port may just survey the scout and declare it an unrecoverable wreck instead! Either way, it sounds like a helluva session!
Have fun,
Bill
1 - There are 'aneutronic' fusion reactions. That's a fancy name for reactions that do not emit neutrons. One involves Helium-3 and is featured greatly in
GURPS:Tranhuman Space. In
Traveller however, helium is never mentioned as powerplant fuel, it's always hydrogen and hydrogen will give us neutrons. Some reactions will produce more and some reactions will produce less, but all hydrogen reactions produce them.
