Reply To: Contour Crafting – Radical change in housing
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theanphibianAeronaut wrote: Glad to have you with us, theanphibian.
A simplified view of the DPF is the Lee model, developed by professor Sing Lee of the UN University. http://www.nsse.nie.edu.sg/research/plasmaphysics/ComputationPkg.htm will get you the Mather style DPF simulator and all of the math behind the simulator, which includes the physics. This model divides each machine cycle into 5 phases, the Axial, Radial inward shock, Reflected radial shock, compressive/radiative, and expansion. As the names imply, the last 4 phases use a cylindrical model.
The link you mention defaults to the general research site. The material was removed at some time in the past. I would offer as an alternative:
This page does offer some novel content, thanks for the leads. The page has some Excel books that can be downloaded with a simulation based in Visual Basic, but it doesn’t work on my computer, oh well. Anyway, I’m not strongly interested in the computational specifics right now, I’m mostly interested in the qualitative physics since I still haven’t fully grasped those yet.
My understanding of the purple image is that its the filaments beginning to kink up near the beginning of Phase 2. I still don’t have a direct correlation between much of the Lee model (simplified but easier to grasp initially) and the LPP model, which is very detailed. But there are 2 simulators being tested. Maybe FF will have a package similar to the Lee model this year.
I understand those are the filaments, that makes sense.
Am I correct in taking that the purple image is from imaging from a real experimental test? Not computational or anything of the sort. But I know the modeling is very important (otherwise you’re wandering around in a 6-dimensional space I hear).
The compressing cylinder is the collapsing magnetic field, which can exceed 10GG, heating the plasmoid containing the fuel for any shot by compressing it into a near solid. The plasmoid diameter for the energy yield charts is 8.6 microns. As the plasmoid is compressed, some fusion begins, producing positively charged helium ions and the resulting free electrons. The magnetic field provides the motion and the tight focus of the beams.
Even though it needs to be shown as a beam for that concept, the electron beam is actually busy heating the plasma even hotter. Something like thermal runaway in an overheating transistor. This is where the majority of the fusion reactions begin occurring.
I was previously looking at the actual pB reaction as a 2-to-3 body problem. But we are mostly interested in the dynamics of a He (as the reaction product) gas within the plasmoid confinement. So at 10 GG we will see a huge effect from that. Also, since it’s so dense, the coulomb interactions between ions will be abundant… I’m just thinking out loud here, I’ll keep reading up. I believe it’s completely possible for the beams to happen but it seems odd that one would be positively charged and the other negatively charged. I could see it happening, but I’m vague on the specifics.