If that's the case, would the tungsten flask heat up to 2000C and give off the photons that are absorbed by the TPV? I still don't understand how they will control transmission of the heat at those temperatures.
Maybe insulate with reinforced carbon-carbon? I'm not an expert on this, but it doesn't seem outright impossible on the surface, but the details are always what get you.
The insulation I sort of understand. It's how they temporarily breach the insulation to let out the photons to strike the TPV that I don't understand. With normal heat->electricity conversion, you transfer heat to a turbine via a fluid (i.e. water) that is allowed to contact the exterior of a heated vessel, but in this case you need to somehow open a slot to let the photons radiate out.
Install a hinge on the side of the insulation box, swing it open then swing closed a different section that includes the thermocouples?
Or just slide the insulation down in front of the thermocouples when they aren't needed. I have to assume these things mostly work on radiant heat at those temperatures.
You need vacuum super insulation.
Basically take a thermos, and fill the vacuum with (mostly) non-touching reflective foil. It's the golden stuff satellites are wrapped in.
