Solar Furnace Suns Concentration

15,000 suns, as you are using it is ambiguous. At the distance of Earth,
the Sun delivers what is called the solar constant, 1360 watts per meter
squared. A large mirror could focus the energy to raise it to much higher
values, but the temperature would be ~ 6,000 K max. No known material
remains solid (or liquid or gaseous) at that temperature, but becomes a
plasma (ionized). I don't know if this helps or not. Sincerely, Jay
Huebner

Is it possible to direct a beam of 15,000 suns from the focal point
of a parabolic mirror down a path into a furnace chamber?

I know the easiest solution is to have the focal point be right in
the furnace chamber but I'm trying to look at the issue of the
layout of a materials processing facility and it would be easier to
design the workflow if the beam could be channeled into the furnace.

I guess a part of my question is how well a polished surface can
reflect and channel a beam of energy of 15,000 suns? What material
would be considered for the channeling tunnel?

Thanks for your insights.