Patent of the Month – Fusion Power (Almost)
Editor | On 10, Nov 2019
For the most part, the words ‘nuclear’ and ISIS don’t really belong in the same sentence these days. Fortunately, the ISIS in question here is ISIS Innovation Ltd, an offshoot of Oxford University. I’m assuming the company was formed quite a while ago. Anyway, they are responsible for our Patent of the Month this month. US 10,315,180 was granted to a pair of inventors at the Company on 11 June. The ‘nuclear’ part of their work perhaps also requires a little bit of qualification. Here’s what they have to say about the problem being addressed:
The development of fusion power has been an area of massive investment of time and money for many years. This investment has been largely centered on developing a large scale fusion reactor, at great cost. However, there are other theories that predict much simpler and cheaper mechanisms for creating fusion. Of interest here is the umbrella concept “inertial confinement fusion”, which uses mechanical forces (such as shock waves) to concentrate and focus energy into very small areas.
Much of the confidence in the potential in alternative methods of inertial confinement fusion comes from observations of a phenomenon called sonoluminescence. This occurs when a liquid containing appropriately sized bubbles is driven with a particular frequency of ultrasound. The pressure wave causes bubbles to expand and then collapse very violently; a process usually referred to as inertial cavitation. The rapid collapse of the bubble leads to non-equilibrium compression that causes the contents to heat up to an extent that they emit light.
It has been proposed in U.S. Pat. No. 7,445,319 to fire spherical drops of water moving at very high speed (.about.1 km/s) into a rigid target to generate an intense shock wave. This shock wave can be used to collapse bubbles that have been nucleated and subsequently have expanded inside the droplet. It is inside the collapsed bubble that the above-mentioned patent expects fusion to take place. The mechanism of shockwave generation by high-speed droplet impact on a surface has been studied experimentally and numerically before and is well-documented. The present invention differs from U.S. Pat. No. 7,445,319, even though the fundamental physical mechanisms are similar, because it does not utilize a high speed droplet impact.
That last sentence gives us as good a clue as any to the conflict the ISIS solution tackles – the desire to achieve fusion being prevented by the need for high speeds. Here’s what that pair looks like when mapped on to the Contradiction Matrix:
And here’s how the inventors have solved the problem, as described in the main Claim of the patent:
A method of producing a localised concentration of energy comprising: creating at least one shockwave; propagating the at least one shockwave through a non-gaseous medium; allowing the at least one shockwave to be incident upon a pocket of gas suspended within the medium, wherein the pocket of gas is spaced from a concave surface; and reflecting said at least one shockwave from the concave surface onto said gas pocket.
The most obvious connection to the Inventive Principles recommended from the Matrix is perhaps also the most surprising one. How did the Matrix ‘know’ that (Principle 14) curvature (i.e. the concave surface) would help solve the problem?
The biggest resource, after the curved surface, seems to be the shockwave. There are several possible ways of connecting this to the Inventive Principles. Principles 13 or, better yet 22, would allow us to see the shock wave as an otherwise ‘bad thing’ that gets to become a very useful thing. We could also see it as a Principle 35, Parameter Change, specifically, Principle 35E, Change the Pressure. Especially since the shock wave is all about creating a non-linear step-change in the pressure characteristics of the flow.
Finally, there’s the reflecting of the shockwave to magnify the energy concentration effect. It’s a bit of a stretch – one that would require quite a lot of lateral thinking – but what’s happening with this reflection is consistent with the recommendations of Principle 8, ‘Anti-weight’. I think I would have got to the reflection idea more easily from Principle 17, Another Dimension though.
That we can make a connection to the Matrix recommendations is good from the perspective of demonstrating the breadth of the tool’s applicability. But I think what we also get from patents like this one – one that sits right at the very edges of mankind’s knowledge of the world – is how it offers up the potential to offer new directions that aren’t explicitly provided by today’s version of the Matrix. That’s something that doesn’t happen very often these days. It took only seven years for Matrix 2003 to lose accuracy to trigger the publication of Matrix 2010. Today, nine years later, and Matrix2010 is still over 96% accurate. Which either means that we’re approaching some kind of universal truth. Or – more likely I have to say – the quality of inventions today is not what it was a decade ago.
Either way, let’s not take anything away from US10,315180. Any solution that achieves great things by exploiting pressure non-linearities and a bit of curved geometry should serve as a reminder to all of us the importance of making what’s already present in a system work much harder before we allow ourselves the luxury of adding stuff.
The patent document is also well worth a deeper look. Here’s the part describing the Figure 2 images at the beginning of this article:
FIGS. 2a, 2b and 2c show three successive stages of a shockwave interacting with a pocket of gas 12 spaced from a surface 16 in accordance with another aspect of the invention. In this embodiment the pocket of gas 12 is immobilized in the gel 18 in a concave depression 14 in the surface 16.
FIG. 2a shows a shockwave 20 propagating through the gel medium 18, in the direction of the arrow, approaching the gas pocket 12. FIG. 2b shows the shockwave 20 as it is incident for the first time upon the gas pocket 12. The shockwave acts on the volume of gas 12 to compress it, in a similar manner to the embodiments shown in FIGS. 1a and 1 b. At the same time the shockwave 20 is reflected from the upper sides of the concave depression 14 in the surface 16.
FIG. 2c shows the third snapshot in the sequence, by which time the shockwave 20 has passed through the volume of gas 12, compressing it significantly. Also by this time, the shockwave 20 has been reflected from the surface 16 and is travelling back towards the pocket of gas 12 in the direction indicated by the arrow. The reflected shockwave 20 now has a shape resembling the shape of the concave depression 14 and is focused towards the pocket of gas 12 upon which it is incident for a second time, compressing it further and therefore further increasing the temperature and pressure within it.