Re: starship-design: Hull Materials

[Antonio C T Rocha <arocha@bsb.nutecnet.com.br>]

This is more or less what I was afraid of.
I imagine the percieved opacity of the shield depending on the frequency of
impinging radiation.

In other words, at relativistic speeds, will infrared be seen as x-rays (and
x-rays as gamma... and so on) ?

If this turns out to be so, there might turn out to be a lot more hard
radiation to be faced. And hard radiation can be more penetrating, hence
difficult to keep out.
Infrared, for example, has a hard time going through glass, but light has no
problem at all.



L. Parker wrote:

> On Monday, November 10, 1997 7:04 AM, Timothy van der Linden
> [SMTP:TLG.van.der.Linden@tip.nl] wrote:
>
> > My theory and tables mainly talk about mu/rho [gm/cm^2] (mass attenuation
> > coefficient) when considering X-ray shielding. For low X-ray energies the
> > photo electric absorption by the K,L,M electronshells seems to be the
> > dominating factor. It looks like we once again need tables to know what's
> > best.
> >
> >
> > Timothy
>
> I don't have anything like the tables you are describing...
>
> I think the alloy of Tungsten was with chromium and iron. There is some
> promising new work in "intermetallics" which might yield even better long
> term performance. So far however, most of the intermetallic research has
> been with Aluminum for turbine blades with a sustained operating
> temperature around 300 C for only a few thousand hours of operational life.
> We need on the order of 500 - 900 C for tens of thousands of hours for hull
> materials and 2,000+ C for drives.
>
> Lee