Occasionally we hear stories about the latest breakthrough in controlled fusion research, and for good reason. If controlled fusion could be made to work, and work consistently and safely, then there would be an energy revolution, and accordingly, a financial and economic one. The reason is fairly clear: financial systems mirror physics systems. If one is working with an essentially closed physical system of limited resources to produce limited energy, the financial system will be a closed system, with "haves" and "have nots". Introduce workable controlled nuclear fusion, and the energy system becomes for practical intents and purposes an open one, such would be the dramatic improvement of efficiency of energy production. The world's dependence on "fossil" fuels - and I enclose the familiar term in quotation marks because I've personally never accepted the story that "fossil" fuels are indeed from the remains of decomposed fossils - would be slashed overnight; nations such as Russia, Iran, Iraq, Saudi Arabia, Venezuela, the USA depending on fossil fuels for a large part of their GDP, would see their economies dramatically curtailed.
If it can be made to work...
In that regard, S.D. shared the following article that caught my eye and, as might be expected, once again revved up my high octane speculation motor, propelling to the quivering end of the twig of speculation:
What caught my eye here was the new concept to reduce the size of the standard fusion reactor design which relies on tokamak magnetic field plasma containment:
The CAT concept is described in an article published on 19 March in the journal Nuclear Fusion, and was developed from first-of-a-kind reactor simulations. The physics-based approach combines theory developed at the General Atomics (GA)-operated DIII-D facility with computing by Oak Ridge National Laboratory scientists using the Cori supercomputer at the National Energy Research Scientific Computing Center, and is based on development and testing of the underlying physics concepts on DIII-D.
"The key to our approach is to raise the pressure inside the tokamak," the project's lead, Richard Buttery, said. "This makes more fusion occur, allowing us to reduce the current, which in turn makes the plasma easier to sustain and more stable. Our simulations show that by carefully shaping the plasma and moving the current toward its edge, we can suppress turbulent heat losses and support higher pressures at lower currents, to reach a state where the plasma sustains itself. This enables a device that can simply be turned on, generating electricity continuously in a steady state." (Boldface emphasis added)
Now this seems to be such an obvious "tweak" to the standard designs for magnetic field containment that I have to wonder (here comes the high octane speculation part) why it has not been tried or proposed long before now, and my guess is, that it has. We're just being informed about it now. What's more important here is the implied quest for making a large installation much smaller, and perhaps even portable. Recall a few years ago Lockheed-Martin released a commercial about a new type of fusion reactor that was so small and portable it could fit into the cargo container of a semi-truck, or even in the bed of a standard pick-up truck.
(See my previous blogs on this subject here:
When I saw the commercial I was immediately suspicious, for Lockheed's device - at least in its artistic-advertising version - looked suspiciously like the diagrams in the patents of Philo Farnsworth, a connection I noted in the second blog linked above. The problem, as I saw it then and still see it now, is that Farnsworth's devices were constructed and tested in the early to mid-1960s. According to Farnsworth, they worked. He even gave a press conference about his results, and then they were never heard from again. There was another problem with Farnsworth's devices...
... they were small, about the size of a standard softball.
My point here is not about whether or not Farnsworth's devices actually worked, nor if Lockheed's actually works (I personally tend to believe that they probably did and do). Rather, my point is the quest for compactness and even portability, and this latest concept of a plasma under high pressure requiring less current seems to my mind quite promising, and probably has already been quietly - that is to say, secretly - developed and tested.
The utility of "compact fusion reactors" of the hot plasma sort would seem rather obvious: large installations or perhaps even entire small towns could be run with them... think underground installations, or Moon bases, or comparatively large space stations...
But here comes my constant problem, one which always makes me far more hesitant about controlled (hot) fusion than all the fanfare promoting it. I certainly don't mean to rain on the fusion parade, but nonetheless the issue gets far too little coverage in popular stories about it, and the issue seems doubly applicable here: what happens if their is a sudden and catastrophic failure of the magnetic, and now in this case, the pressure containment of the plasma? If there is a sudden failure of the containment of the pressure vessel, then it would seem to follow that the smaller power required for the magnetic containment will fail as well. This could have...well... explosive consequences.
Hopefully, "they" are thinking about these things, and incorporating their solutions in their designs. But it would seem to be a thorny and indeed prickly engineering problem: how does one shield a hot pressurized plasma fusion reactor under magnetic containment from electro-magnetic pulse, for example?
See you on the flip side...