Tag Archives: Nuclear Fusion

The Other Kind of Fusion – General Fusion

When it comes to nuclear fusion size matters.
When it comes to nuclear fusion size matters.

Recent news with regards to nuclear fusion research has not been good:

Yet, just as D-Wave was mostly off the radar with regards to quantum computing, there is another Vancouver based high tech venture that could similarly upset fusion research.

The hot fusion plasma ball up in the sky, when compared to the general fusion challenge down here on earth, is really, really big; It generates an enormous amount of pressure at its core, creating the kind of critical density that assists in sustaining the fusion reaction. So just heating a plasma to the Sun's core temperature (about 16 million K) will not suffice, we have to do about ten times more than that in order to compensate for the lack of gravitational pressure. It shouldn't be surprising that designing a reactor chamber that can hold the hottest thing in our solar system poses a significant engineering challenge.

On the other hand, the idea of tackling the second parameter, the plasma's pressure, in a controllable manner, was generally regarded as technically impossible (not counting NIF like implosion scenarios that more mimic the runaway implosion of a H-bomb, which is why they are interesting to the military).

This common wisdom held until General Fusion entered the fray and made the case that advances in electronics and process control opened up the possibility to tackle the density side of the fusion equation.  And then they built this:

Screen Shot 2013-06-02 at 2.12.23 PM
A device that would fit nicely into the engine room of a spaceship and not look out of place on a SciFi set.

This device is following the age-old engineering adage that if you want compression you use a piston, and if you want large compression you use a large piston which focuses all the energy into a tiny space.  The trick is to be able to do this in such a precise fashion that you can coordinate it with the injection of fuel gas along a central axis, so that you can get a succession of pulsed fusion ignitions with each coordinated firing of the pneumatic pistons.

As with most fusion reactor schemes the envisioned reactor will be fairly compact.
As with most fusion reactor schemes, the envisioned reactor will be fairly compact.

When I first heard about this concept, I thought it was completely off the wall, but the math checks out and there have been other experiments to confirm the viability of this approach.

This device may be testing the limits of mechanical engineering, but if it can create the condition it aims for, then our current understanding of plasma and nuclear physics clearly indicates that it will result in fusion.

The interior of the reactor chamber will have to be cooled with liquid lead. Despite this high energy density, the overall footprint of just the reactor itself is fairly compact, no bigger than the typical dimensions of a commercial nuclear fission reactor. If this design pans out, these reactors could be used to retrofit existing nuclear power stations with a fusion core, converting them to a much cleaner energy source that does not come with the risk of accidentally triggering an uncontrollable nuclear chain-reaction.

The timeline for bringing this to the market is aggressive.  If General Fusion delivers on it, there will be a commercial fusion offering available before ITER even opens its doors.

Given that the latter is not even attempting to deliver a commercial ready design yet, the company will be without competition (unless some of the other commercial fusion ventures such as LPP should beat them).

GF Timeline

Fortunately, with this company it won't be hard to decide when and if they manage to deliver on their promises (there won't be any grounds for the kind of academic backlash that D-Wave has to endure). Unlike in the world of fringe science, where even the simple act of measuring (supposedly) substantial energy gain is obfuscated to the point of utter hilarity, once General Fusion achieves energy net gain, there will be little doubt that we entered the dawn of a new energy age.

(SOURCES: General Fusion Web site, GF 2012 progress report)