Re: Unobtanium Radiation Shielding?

CharlesRCaplan@[EMAIL PROTECTED]
 schrieb:

> needing deep layers of the stuff to make sure that a nucleus is struck
> by the ray before it exits the material? Would this material be
> significantly lighter than solid slabs of lead of equivalent
> protectiveness?

In a 3-dimensional matrix some nuclei are shadowed by others and can'T 
contribute, if you reduce your protective layer to two dimensions, they 
are either used to increase shielding or left at the factory, saving you 
mass.

> I also know that part of the problem with using thin sheets of
> material to stop gamma radiation is that the secondary particles that
> are produced when a nucleus is struck are actually worse than not
> stopping the gamma rays at all. So if we produce a thin nanotech
> material that stops the gamma rays but produces these secondary
> particles, can we back it with some other material (lighter than lead
> or gold or whatever) that can stop the secondary particles at a lower
> mass penalty than the main material?

Materials that contain a lot of hydrogen are good at this.
That water you want to use for some of the cooling systems could double 
as shielding mass, structures made from PE/PP-plastics are also quite 
useable.