TAE completes first tests of hydrogen-boron fuel cycle

[JoeStrout]

https://www.rechargenews.com/energy-tra ... cUhI2pXtK8

Thoughts, analysis, and opinions?

[RERT]

I guess the big news is in the Nature paper: that updated cross-sections mean that a pB11 plasma can reach ignition. Previously mainstream wisdom was that the fuel was a dead-end inna stable plasma because Brehmstralung losses would exceed fusion power.

‘Diagnostically significant’ fusion alphas might be bugger-all. Didn’t read far enough to check…

[Giorgio]

It is worth noting that the result was achieved on the "Large Helical Device" (LHD) which is a Stellarator type of machine like the W7-X!

The LHD has been developed to reduce plasma vortex turbulence diffusion, while the W7-X has been developed to reduce ions-electrons collisional diffusion, and there is already work going on to integrate the 2 design in a single new machine.

If they actually got pB11 ignition in the LHD it opens a huge expectation for the w7-X where the collisional diffusions are one order of magnitude lower than LHD.

They will not be a contender for "first team to fusion" but on the long run Stellarator might become an interesting compact alternative for an inherently stable fusion device.

[RERT]

Here is a link to the article on raised p11B fusion rates (from 2019) - up 30%. 'Fraid I don't have access to the full text to know what that really means.

https://iopscience.iop.org/article/10.1 ... 326/ab1a60

[Giorgio]

Here is a link to the article on raised p11B fusion rates (from 2019) - up 30%. 'Fraid I don't have access to the full text to know what that really means.

https://iopscience.iop.org/article/10.1 ... 326/ab1a60

This paper is available on TAE website just click HERE.

The summary of the article is that by accounting for some factors that Nevis didn't account for in his 2000 paper, the cross section was showing a marked increase and the Fusion power density was able to overcome the Bremstrahlung losses (while in the Nevis study there was a large gap between the 2).

These modified factors was (in order of importance):
a) the Kinetic effects of protons on the Alpha particles and the electrons
b) a revised distribution profile of the Alpha particles due to new experimental results and theoretical framework
c) a revised interaction model of energy exchange between the ions and the electrons.

[RERT]

Thanks Giorgio, I might have chance to rrad tgat on the train later today.

A propos not very much, the charge to mass ratio of boron is only slightly less than D, and the charge to mass ratio of 1H is radically higher than T. On the face of it magnetic confinement ought to be more effective for a P11B plasma than a DT plasma.

Any clue how much hotter you might make p11b in the same trap as DT?

[Skipjack]

Interesting paper. I am wondering what densities TAE is going to use. The paper talks about 10^20 ions/m3 and shows a power density of just 1 MW/m3.
So their burn chamber would still have to be quite huge for TAE's projected power output of 300 MWe. Unless I misunderstood something, or they can indeed reach higher densities than Norman did (which only did a little over 10^19 ions/m3).
Compare that to Helion which is at 10s of GW/m3 power density. Though granted they are pulsed. So it may not be a fair comparison.
What is also interesting is that the temperature is not that high compared to where Helion is operating in at 30keV. Hmmm...

[Giorgio]

Any clue how much hotter you might make p11b in the same trap as DT?

Interesting paper. I am wondering what densities TAE is going to use.

We need to consider that this paper was just a theoretical one that served as the framework for the actual experimental set up, and the cited "Shot number" in the Nature paper is from February 2022, so all the parameters could have been already deeply modified in the following experimental runs, so in truth it is hard to make an educated guess on what working parameters TAE will decide to focus.

I guess we will need to wait some more result reports to have a more clear idea.

[RERT]

FWIW isn’t their power plant design enormous? Like O(~100m)? 1 Mw/m^3 might be Ok. Though in any case I don’t see that having much to do with the paper’s modelling assumptions.

[charliem]

Hi everyone. Long time, no write.

Has anyone access to that Nature article ? A rough idea of the main points would be appreciated.

One think I'd like to know is whether it changes in any way the conclusions from the 2019 paper mentioned before, specially the calculations that show it should be possible to reach ignition using p-11B.

On the other hand, plasma temps in the order of 300-400 keV ? That's a lot of heat, well above present records in FRC machines, isn't it.

By the way, if TAE think they can reach 200 MeV in steady state, wouldn't it be easier with pulsed machines, like Helion's.

[Giorgio]

Has anyone access to that Nature article ? A rough idea of the main points would be appreciated.

The paper is public, you can see it HERE.

By the way, if TAE think they can reach 200 MeV in steady state, wouldn't it be easier with pulsed machines, like Helion's.

Helion is using a different approach altogether. There has been a lot of interesting disclosures and discussion going on in the main Helion Thread.
If it s long time that you are missing from the forum you might want to go there to get updated, is worth the time.

[Giorgio]

FWIW isn’t their power plant design enormous? Like O(~100m)? 1 Mw/m^3 might be Ok. Though in any case I don’t see that having much to do with the paper’s modelling assumptions.

Well, considering the importance of the finding it will probably be anyhow a good time to revise also their planned plant design parameters!