Building a fusion-based electricity generating station is still a number of years away, but there’s a lot more people looking at this than even a decade ago. There’s a lot of innovation and we’ll talk about two ideas here. But first a brief review.
First, Lockheed is not involved in these. That’s a shame. I think Lockheed Martin has a good team, but a friend of mine pretty said that they were asking for working partners because they were stuck.
Third, in case you need it, is a lengthy primer on fusion and fission.
Now for the new stuff. The tokamak (a transliteration of a Russian acronym for toroidal chamber with axial magnetic field) is probably the main focus of fusion research today. ITER is using that design. Basically, it’s a giant donut. The donut is surrounded by powerful magnets, with more magnets in the center. These are used to compress the plasma, heating it, hopefully to the point where the fusion reaction is releasing more capturable energy that the magnets and heaters and ion guns are using.
This first report is about a new kind of tokamak. Instead of a donut, it’s more like a biscuit with a pen hole through the middle. The central magnets are much smaller and the plasma has a higher pressure for a given magnetic field strength. More pressure means more heat and more fusion. So far, the reports look very good.
This design does have it’s issues. More heat means it has to vent some of that heat and the current exhaust systems are a little weak for the work expected of them.
One company has run a spherical tokamak for 15 minutes (at a lower pressure and temperature) and they plan to run their machine for 24 hours this year. Which is handily beat the all time record of 5 hours. Note that this is not a “energy producing system”. They have to provide power to the reactor for that period of time. Still, it’s a necessary research step to see if they can keep the plasma and magnetic fields stable for that amount of time. A reactor isn’t useful if it can only run for 30 seconds at a time.
The second report describes a totally different tactic. Instead of a circular (torus) magnetic confinement ring where the plasma is swirling inside a magnetic field, the company Tri Alpha Energy, Inc. (no website!) has decided to go with a linear collider. It’s just like it sounds a tube with plasma guns at each end that fire plasma rings at each other. This is interesting because, as you know a moving charge creates a magnetic field and plasma is a charged material.
Similar to blowing a smoke ring, where the vortexes are relatively stable over time, this fusion “cannon” fires two plasma vortexes at each other at about 250 kilometers per second. Doing this and few other tricks, they have achieved the highest plasma pressure to magnetic field strength ever. And just a quote from the article that is music to my ears
These features, coupled with its unique linear exhaust capability, also make the [reactor] a highly attractive candidate vehicle for deep-space explorations.
Yes, it will take a long time to get there, but anything that can get us a fusion torch drive has my attention.
More and more research, and media attention, seems to be coming from fusion research. For Earth, I don’t think it’s totally necessary. I think that we can get all the energy we need from other sources. Still, it’s nice to have a back up and fusion is seriously important for human deep space exploration.