Thanks for the info. I agree that the benefits of FF outweigh the drawbacks of the use of Beryllium. I’ve read a DOE document that refers to a classified safe substitute, but I don’t know if it would be x-ray transparent or of any use otherwise. My question would be whether we would consider a safer material such as Boron or other conductive element, even though it may heat up more and degrade faster. If it’s inexpensive enough to produce and recycle. Say it lasts two years instead of Beryllium’s five years for example, would it be worth it as a substitute, given that it is so much less hazardous, less expensive and makes selling the FF concept so much easier?
Also, there are other useful metal alloys out there that could include cooling components as part of there structure. Are these being considered?
... I’ve read a DOE document that refers to a classified safe substitute…
Besides X-Ray transparency, Be has a number of other physical characteristic that make it an ‘ideal aerospace material’, according to Wikipedia.
My guess is that ‘substitute’ refers to other uses, like brakes for military aircraft.
You could also take a look at MatWeb which has information about thousands of materials. There you can compare Beryllium with other materials.
I would suggest pure beryllium is preferable to BeO, because oxygen got more protons and here it’s not a gas but a solid (much higher concentration of atoms).
This actually describes a possible solution for fabricating the x-ray harvesting onion structure around the focus device. Laminating metallic foils is what’s needed for the production of the onion. They investigate Al - Al3Ti composites, so it needs to be adapted to the materials we need.
The high structural stability adds the advantage of having cooling tubes running through, and pushing the coolant through with high pressure. Still one needs to take care of the tubes not collapsing (see figure 11) during the manufacturing process. Maybe a material filling the holes and which is flushed by a solvant later is the solution here.
Ah, I see this subject has already been discussed in a previous thread, “New Anode Cooling ‘Limits’ Likely”, so I’ll stop being redundant with my 2 cents. Glad to see you all have been thinking about material impacts.
Ah, I see this subject has already been discussed in a previous thread, “New Anode Cooling ‘Limits’ Likely”, so I’ll stop being redundant with my 2 cents. Glad to see you all have been thinking about material impacts.
Actually the “New Anode Cooling ‘Limits’ Likely” thread is about the construction and cooling of the electrodes. But the x-ray capturing onion needs cooling too, and it’s not going to work with rapid prototyping, one needs the laminating technique presented here. So keep on thinking about it.
Ah, I see this subject has already been discussed in a previous thread, “New Anode Cooling ‘Limits’ Likely”, so I’ll stop being redundant with my 2 cents. Glad to see you all have been thinking about material impacts.
Actually the “New Anode Cooling ‘Limits’ Likely” thread is about the construction and cooling of the electrodes. But the x-ray capturing onion needs cooling too, and it’s not going to work with rapid prototyping, one needs the laminating technique presented here. So keep on thinking about it.
Now I’m confused, Henning. Are you ruling out CVD machines as well? Making foils this thin, coiling them, shipping the coils, and other factory type operations make me highly skeptical about building onions in volume by hand.
Does the x-ray capturing device really need to be spherical? I realize that shape probably optimizes the capture, but how less efficient would it be to simply create a box with flat sides of laminated materials? Surely that would be far easier to construct, and there may already be flat laminated foils in existence that could be used, rather than creating something new.
I mean you would need something like rapid prototyping for the anode/cathode to include cooling structures. The electrodes would need an uniform material (beryllium, or boron, or…) with a low number of protons. Just because of the complex inner shape of the electrodes rapid prototyping is preferable.
Then on the other hand for the x-ray capturing, layers of different materials are needed. That’s what laminating provides well. And as Tulse writes, a box constructed out of flat panels would be fine, but it still needs cooling channels running through. We just call it the onion, because of its layers (okay maybe also the shape on Torulf’s pictures, but this seems secondary).
Aeronaut: If you mean chemical vapor deposition with CVD for building the x-ray capturing device this could also work. So laminating and CVD would be two solutions to the problem the x-ray converter poses. Maybe even combine these two steps, first do laminating for the outer layers, and then continue with CVD.
Did I sound like I was ruling out that possibility? Wasn’t my intent. Yes, you’re right, we also discussed x-ray capturing in that other thread. Maybe I’ve confused it with rapid prototyping for the onion in one go.
@Henning, glad we’re on the same page except for possibly the laminating. That might work on the outer layers, building inward toward the plasmoid. I’m still thinking CVD building outwards, but that’s not the only way possible.
My key concern is that the patent reads that the onion’s radial cooling passages are most likely only going to be a few degrees apart- i.e.- a complete onion would need around 180 slats to provide the electrical conversion, cooling, and mechanical support. And those cooling channels are very narrow.
Supposing that each X-ray energy band can be converted using 10 to 100 foils (each a different thickness), and a multi MW onion would require several of these slats stacked vertically/ radially, I’m having problems visualizing how to cool, support, and wire a commercial onion without building at least the stacks at the molecular or even atomic level using automated machinery.
Put another way, a research machine could test over 100 slat designs on a monthly robo-building schedule in a networked lab environment. Something like Edison’s 1,000 experiments managed in a series/parallel manner rather than his serial model.
Does the x-ray capturing device really need to be spherical? I realize that shape probably optimizes the capture, but how less efficient would it be to simply create a box with flat sides of laminated materials? Surely that would be far easier to construct, and there may already be flat laminated foils in existence that could be used, rather than creating something new.
From an engineering point of view, a spherical device will be extremely difficult to construct because you can’t start from a stack of flat foils.
Most practical will be a cylinder with a flat endcap (and a hole to let the alpha beam pass through). The vacuum vessel will probably already have this shape.
From an engineering point of view, a spherical device will be extremely difficult to construct because you can’t start from a stack of flat foils.
Most practical will be a cylinder with a flat endcap (and a hole to let the alpha beam pass through). The vacuum vessel will probably already have this shape.
a cylinder of foil would be rather easy to build, yes. but spherical shapes could be made with something like ion beam spattering, alternating layers having different opacity to xrays, and different electrical conductivity.
But are there significant advantages to making it spherical, or even cylindrical? What is the efficiency loss relative to the ease-of-construction of something like a box?
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