Talk-Polywell.org

Very nice and kind rebuttal. Thank you SJ!

Wow, Skipjack, that was much more than I hoped for, thank you so much!

Curious… I’ve been loosely following this board for many, many years and I recall posts that appeared based on personal knowledge or relationships with the Helion team. Don’t recall if that was you… is the rebuttal here based on direct knowledge of the project, or just following it closely over the years?

It is a bit of both
I know David Kirtley quite well (I maintain good relationships with people at several startups). He is a super nice but very busy guy.
I have been following Helion's progress ever since a former board member, Art Carlson who wrote his thesis on why FRCs can never work visited their lab and cam back convinced. That sparked my interest.
Here is his post about the visit:

viewtopic.php?p=24319#p24319

A lot has changed since then and Helion is going for D-He3, which it turns out, their machine should be able to do with 20+ Tesla fields.

Wouldn't a 20 Tesla field require superconducting coils and cryogenic cooling? That would increase the cost, size and complexity of the plant, which would negate what I thought was one of the benefits of their approach.

windmill wrote: ↑

Thu Feb 02, 2023 6:38 pm

Wouldn't a 20 Tesla field require superconducting coils and cryogenic cooling?

Not for a pulsed system.

Divertor added to Polaris Formation Test Section:

Divertors are being installed on the ends of our Polaris FRC formation test this week. Once all divertor magnets and the two quartz tubes are installed, the system will be fit together, pulled to vacuum, and we can start forming FRC plasmas!

https://twitter.com/Helion_Energy/statu ... 30656?s=20

Skipjack wrote: ↑

Thu Feb 02, 2023 6:53 pm

windmill wrote: ↑

Thu Feb 02, 2023 6:38 pm

Wouldn't a 20 Tesla field require superconducting coils and cryogenic cooling?

Not for a pulsed system.

Took a while to notice, but if you had cryogenic superconducting coils in a pulsed system, what kind of peak fields might be achieved?

RERT wrote: ↑

Thu Feb 16, 2023 8:18 am

Skipjack wrote: ↑

Thu Feb 02, 2023 6:53 pm

windmill wrote: ↑

Thu Feb 02, 2023 6:38 pm

Wouldn't a 20 Tesla field require superconducting coils and cryogenic cooling?

Not for a pulsed system.

Took a while to notice, but if you had cryogenic superconducting coils in a pulsed system, what kind of peak fields might be achieved?

I am not sure. Generally there is a limit for super conductors for how strong a magnetic field can be before they start losing current, from what I understand. AFAIK, for HSTCs it is higher, but not unlimited.

Superconductors come with a whole lot of baggage too from the requirement for cryogenic cooling and quench issues. Cryostats need a lot of power which reduces system efficiency. Cooling down the magnets takes time. That increases startup time.

How short are the pulses on the coils on the acceleration section?

RERT wrote: ↑

Fri Feb 17, 2023 9:43 am

How short are the pulses on the coils on the acceleration section?

I think they mentioned it in one of the videos. I can't remember, but it has to be somewhere in the microsecond range.

Hi - two criticisms of Helion surfaced yesterday. I don’t give them much credence, but woukd appreciate a clear response if anyone has one.

1) the highly reactive T will ‘scavenge’ D from the plasma, making the reaction quite neutonic even in He3 operation.

2) the generation of He3 from D will consume power, degrading the overall through-cycle efficiency.

Here is a link:

https://protonsforbreakfast.wordpress.c ... -delusion/

First mistake:
1. D-He3 results in He4 + p not He4 + T.
2. Helion actually wants the D-D side reactions to make He3. They will need about 2 D-D reactions for every D-He3 reaction. Tritium will only be produced in 1/3 of the reactions in the machine.
3. The Tritium is over 1 MeV when it is "born". It is too hot and non- collisionional on the timescale of the pulse.
4. The fusion products including Tritium will be a small percentage of the total fuel in the machine. So even IF some D-T reactions were to happen, they would only consume a tiny minority of the D and there would still be enough D left to fuse with He3 (or other D).
5. Helion plans to run at temperatures between 200 and 300 million degrees.
6. Due to the high Ti:Te ratio - which increases with temperature - D-D and D-He3 reactivity is actually much closer to D-T reactivity.

Helion capacitor storage has arrived and Polaris formation test article:

Posted a comment in the blog and actually got a friendly response from the author. Not sure where it will go, but we will see.