Helion Energy to demonstrate net electricity production by 2024

[Giorgio]

Indeed I checked and you are correct, the 1 ms value was for the Trenta and they (officially) didn't reach it as confinement stopped at 0.04 ms due to the rotational instabilities as I have been saying.

Reference please!
Venti was the one with 0.04 ms TauE, IIRC. Trenta did significantly better, AFAIK.

Because n=2 rotational instabilities will arise immediately and disrupt the field at around 20 to 40 us unless corrected.
It is an inherent characteristics of all FRCs, from the time when Slough was working at LSX in the 80's and 90's..... LSX had to implement several multipole fields to stabilize the n=2 rotational instabilities to get some decent results, else the machine was performing with less than 20 us stability times before rotational instabilities was disrupting the field. With the stabilizing effect they was able to reach up to 500 us.
Helion (as well as TAE) was born from the LSX experience and inherited the same issues while trying different approaches to control it. At least on this point TAE has always been much more clear than Helion, while Helion never clearly said "we are solving it" nor "we still have trouble with it".

If you want a reference from Trenta at all costs, you know already that the only one that can give it to us is Helion itself and they clearly do not seem willing to disclose it (and I am sure they have their own rightful reasons).
The only data they gave in the video is the table at 11:40/12:25 where they give the "ratio" of the Trenta lifetime over the the LSX expected lifetime..... pretty useless unless you know what is the expected LSX value that they considered.

Again, I am not questioning the reasons why they are hiding these results. They are a commercial company with investors, they have to make decisions on what to disclose, and I am perfectly fine with that.
But until the moment they at least say in a clear way "we have a road to solve it" or "we solved it", we can't ignore this issue.

[Giorgio]

Again, it might as well be that they solved the issue and didn't want to disclose it, no one knows, but the issue is real and is there from 15 years waiting to be solved as it is a roadblock for everyone working with FRCs and hoping to get to Q>1.

Is this what Dennis Whyte has in mind when he says that FRC:s are a thousand times to leaky?

I think so.

Is it the long enough parameter in hot enough, dense enough, long enough?

Yes.

[Giorgio]

On the other hand, plasma compression is unproven for Zap, & they admit that their latest modeling is where their confidence lies. Also, their machine is not that expensive to build & the reason their time line for Q>1 is short (2023 as I recall, & their machine is up & running as we speak). So, I put Zap in my '?' column until they reach Q>1, & even then until commercial compression levels are reached I harbor doubts that some instability might appear.

Yes, these are the issues with ZAP. The pinch diameter reduction without incurring in a new instability will be at the heart of their success or failure.

[Skipjack]

Very brief response from David Kirtley on the short life of FRCs claimed by Giorgio:
"Not sure what they are talking about. That might have been true for little IPA- sized plasmas."
Trying to get some more info with hopefully some numbers for Trenta, but he has been super busy. So no promises.

[Skipjack]

In other news, Helion's Jessie Barton was at the COP 27. Not much news for us, but could be interesting to some. Still on track for 2024...
https://www.youtube.com/watch?v=FPbvODcWXKs

[Giorgio]

Very brief response from David Kirtley on the short life of FRCs claimed by Giorgio:
"Not sure what they are talking about. That might have been true for little IPA- sized plasmas."
Trying to get some more info with hopefully some numbers for Trenta, but he has been super busy. So no promises.

Well, I am not sure to what point he is referring to, but I do not think that TAE can be considered a small IPA plasma, and they are suffering n=2 instabilities like every other FRC experiment so far. This is also the reason why they need to employ plasma guns and neutral beams to stabilize and keep field life.
They provided plenty of data to show this.

I just hope that he can simply clarify their situation on the instability issue once for all.
And if he could disclose any numbers to prove that all my doubts are not a concern for their roadmap, than that would really be interesting.

[Skipjack]

Well, I am not sure to what point he is referring to, but I do not think that TAE can be considered a small IPA plasma, and they are suffering n=2 instabilities like every other FRC experiment so far. This is also the reason why they need to employ plasma guns and neutral beams to stabilize and keep field life.

TAE has been holding their plasmas stable with neutral beam injectors for tens of milliseconds. Helion does not need that long. Is there a reference that their larger machines experienced n=2 instabilities within 10s of us without NBI?

[mvanwink5]

There is more to stability than 'FRC Plasma'. Temperature for example is important, as plasma Temp increases so does stability. Further General Fusion spent years finding the plasma topology that was stable under adiabatic compression. I would presume that Helion realized what worked early on. GF could get no help on their research due to its application to weapon technology.

The point I am trying to make is that how the FRC plasma is made is critical to stability.

[Giorgio]

Well, I am not sure to what point he is referring to, but I do not think that TAE can be considered a small IPA plasma, and they are suffering n=2 instabilities like every other FRC experiment so far. This is also the reason why they need to employ plasma guns and neutral beams to stabilize and keep field life.

TAE has been holding their plasmas stable with neutral beam injectors for tens of milliseconds. Helion does not need that long. Is there a reference that their larger machines experienced n=2 instabilities within 10s of us without NBI?

This as example from 2018 or This one, or even this very interesting paper here.

The last one is very interesting even if a little dated (2012). In general you can just search for "instability" on their website to find plenty of papers and posters with data relating to N=2 instabilities and other instabilities.

[Giorgio]

There is more to stability than 'FRC Plasma'. Temperature for example is important, as plasma Temp increases so does stability. [.....]
I would presume that Helion realized what worked early on.

Indeed this is a possibility, even if simply increasing temperature will not inherently ensure a stable plasma. There is plenty of other factors effecting it, and some latest research I read (not related to TAE or Helion) made even the case that as you increase plasma temperature there will be a limit over which FRC instabilities (some of them) will increase instead of decreasing

[Skipjack]

Indeed this is a possibility, even if simply increasing temperature will not inherently ensure a stable plasma. There is plenty of other factors effecting it, and some latest research I read (not related to TAE or Helion) made even the case that as you increase plasma temperature there will be a limit over which FRC instabilities (some of them) will increase instead of decreasing

So got a quick reply from David (they are super busy with deliveries of Polaris parts) and as I understand it, for n=2 instabilities radius is what is important.

Onset of rotation scales similar to particle confinement time. At least rs^2.1 if not stronger.

Hope that settles that matter.

[Giorgio]

So heard back from David (they are super busy with deliveries of Polaris parts) and as I understand it, for n=2 instabilities radius is what is important.

Onset of rotation scales similar to particle confinement time. At least rs^2.1 if not stronger.

Yes, confinement time in FRC is scaling with rs^2.1 up to now, this has been the reference value since Slough's MSWN DOE research from 2010. But we all know this is not an absolute formula guaranteed to scale as we push boundaries. We have seen this many times over in the past. I feel that he choose to give us a political reply.

Fair enough, I hope there is more to it than what he could say, 2024 is not that far anyhow. Thanks for taking the time to ask him.

[Skipjack]

So heard back from David (they are super busy with deliveries of Polaris parts) and as I understand it, for n=2 instabilities radius is what is important.

Onset of rotation scales similar to particle confinement time. At least rs^2.1 if not stronger.

Yes, confinement time in FRC is scaling with rs^2.1 up to now, this has been the reference value since Slough's MSWN DOE research from 2010. But we all know this is not an absolute formula guaranteed to scale as we push boundaries. We have seen this many times over in the past. I feel that he choose to give us a political reply.

Fair enough, I hope there is more to it than what he could say, 2024 is not that far anyhow. Thanks for taking the time to ask him.

I don't think that he meant that onset of rotation instability is directly tied to confinement time, but rather that it scales at a similar (or better) rate with rs. So even if confinement time does not scale quite as well as they push the boundaries, the rotation instability might still be scaling at that same rate. Also note that with the results from Trenta, they should (seem to) be already quite close to what they need in terms of stability anyway. So might not even have to scale up (much) more.
Generally from what I have heard, there does not seem to be any theoretical limit for how big you can make these things. So if everything else fails, they can always go a bit bigger (though that would have a negative effect on economics).
My personal hope is that they will actually find ways to make them more efficient and maybe even slightly smaller in the future (though wall loads, etc put limits to that).

I wished he had more time too. If it is any consolation, he too regretted not having more time to go into details but as I said, he is super busy with Polaris deliveries at the moment. I totally understand and respect that.

[mvanwink5]

Busy with deliveries is wonderful news. Delayed deliveries is what kills schedules. Fabrication in house of machine work and manufacturing of high voltage capacitors is also good news (previous insights by DKirtley). 2024 target reconfirmed is bottom line; it is not that far off.

[mvanwink5]

Stumbled across this youtube video that covers Helion, General Fusion, & First Light.
https://www.youtube.com/watch?v=yNP8by6V3RA

It is a reasonable survey of some companies that are pursuing aggressive timelines as compared to ITER, and surprisingly it is not pessimistic like some past Youtubers. On the other hand it is guarded on its assessment of possible successes. No great insights into any company.