Helion Energy to demonstrate net electricity production by 2024

[baking]

This just popped up:

https://www.youtube.com/watch?v=m_CFCyc2Shs&t=67s

"David Kirtley: Nuclear Fusion, Plasma Physics, and the Future of Energy | Lex Fridman Podcast #485"

Two and a half hours. I haven't watched it yet.

I've watched most of it, but there is only one passing reference to Polaris in the transcript:

https://lexfridman.com/david-kirtley-transcript

[jrvz]

Much of the show was background information. My notes from latter part of the interview:

1:41 With FRC, one can recover the input energy at 90 or 95%, and the fusion energy at 80%

1:43 D-T fusion requires about 100 million degrees. D-3He requires a higher temperature (200 or 300 million degrees), which for a given magnetic field strength, will reduce the plasma density, which means the machine has to be bigger than for D-T. However, if you can recover electrical energy at 80% efficiency instead of 30%, the machine can be smaller. The net effect is that the D-3He machine can be about the same size as for D-T.

1:51 What they learned from each prototype system
Inductive Plasmoid Accelerator (IPA) 3 2 keV
Grande schieved 5 keV
Venti achievced 6.4e18 keV-s/m^3
Trenta achieved 100 million deg C and 8 Tela compression, D-3He fusion

1:57 We take any shortcuts that keep functionality and safety. For example, a turbo-molectular vacuum pump takes 9 mo to buy - but in two weeks we can get three decade-old pumps from eBay. and use the one that works.

2:07 There are now 500 people at Helion.

2:13 They could power a data center without converting from DC to AC and back to DC. The data center and the power plant might also share cooling systems.

2:17 Look forward to producing one 50 MW power plant a month -- one a week -- one a day.

2:25 Spacecraft near Earth use solar power, but in deep space that gets impractical. Nuclear power uses fuel with high energy density. However, nuclear generators using a steam cycle are hard to cool.

[Skipjack]

Yeah, those are pretty much confirmation of things that we had already known or had at least concluded from the information available.
Still great to have all of that in one place and directly from David Kirtley himself. So, thanks for the summary.

[mvanwink5]

2:25 Spacecraft near Earth use solar power, but in deep space that gets impractical. Nuclear power uses fuel with high energy density. However, nuclear generators using a steam cycle are hard to cool.

Siting is one of the biggest issues for all electric generation plants, not just space. Of the many factors that limit site options & choices, heat rejection is the toughest to skirt, & generation plants that use a thermal cycle are burdened by huge heat rejection. Helion because of their ability to extract electric power magnetically directly from the plasma itself escapes the Carnot Cycle heat rejection burden, & as a result has the easiest overall siting advantage on Earth as well as space.

However, not much has been talked about the power cabling from the capacitors to the magnet rings. It's not as simple as timing, inductance, & current capacity. No one so far talks about microsecond pulses of Gigawatts traveling over conductors; there must be huge RF generated. Normally, coaxial cables are used, but that's for signals, but for gigawatt microwave power? Surely, military tech has explored this, but Helion shows simple, heavy duty conductors just lying in able trays. LOL. All I know is this is not a simple issue, & we have seen that Helion has test setups to investigate it, so Helion must have a handle on it. I don’t think we have seen the details. Folks here seem focused on plasma, fuel, but there are real issues that only Helion has due to the method of plasma formation, acceleration, & power extraction.

Helion deserves great respect for the unique Electrical Engineering technical challenges they have to work through that gives them their siting advantage.

[mvanwink5]

David Kirtley response,

Totally right - it isn’t simple! In these photos you are seeing impedance matched coaxial cables - specially designed for the minimum resistance for the operational pulse width, to minimize internal reflections, and to minimize flux loss (EMI). A lot of good engineering happening in that simple black cable.

[TallDave]

Much of the show was background information. My notes from latter part of the interview:
1:41 With FRC, one can recover the input energy at 90 or 95%, and the fusion energy at 80%

that's funny, 80% was actually my BOE/WAG a year or so ago... don't think they've given out a number before

[TallDave]

2:25 Spacecraft near Earth use solar power, but in deep space that gets impractical. Nuclear power uses fuel with high energy density. However, nuclear generators using a steam cycle are hard to cool.

Siting is one of the biggest issues for all electric generation plants, not just space. Of the many factors that limit site options & choices, heat rejection is the toughest to skirt, & generation plants that use a thermal cycle are burdened by huge heat rejection. Helion because of their ability to extract electric power magnetically directly from the plasma itself escapes the Carnot Cycle heat rejection burden, & as a result has the easiest overall siting advantage on Earth as well as space.

yes... obviously in space Helion's huge advantage is the size of their reactors, but the lack of convective cooling means they save a ton of radiator surface area with direct conversion... like around 10x smaller

but just imagine trying to lift ARC into orbit... to say nothing of ITER, which probably weighs many times more than all the payloads ever moved to space combined

[mvanwink5]

LOL, for sure ‘easiest’ does not equal easy. Nothing is easy in space.

[usesbiggerwords]

Just as a conversation starter, what does 50 MWe buy you in space? Science-fiction style high thrust ion/Hall thrusters? Mars in weeks instead of months?

[TallDave]

Just as a conversation starter, what does 50 MWe buy you in space? Science-fiction style high thrust ion/Hall thrusters? Mars in weeks instead of months?

believe it depends on how much reaction mass you're willing to add in exchange for ISP

iirc at max ISP, a stream of 50MWe directed MeV fusion outputs would only be tens of newtons at best, but the fuel would last a really long time

[TallDave]

But I think that the market will be big enough to support not just one, but several fusion companies, all with their own strengths. I think that the next 3 years will see fusion booming in a way that few people (maybe the most optimistic ones here) would have predicted. The dot com boom will be a mere footnote compared to what is coming. Take my word for it!

maybe, but I think it's more likely ARC will be the last tokamak ever built

sort of like steam locomotives, it works but why do it if you have diesel?

as far as I know there's no particular reason fusion adoption should be fast even if it's significantly cheaper than LWRs (ARC won't be close) and (AI notwithstanding) new generation will either be mainly happening in space or (more likely) not at all given crashing populations so I wouldn't expect any huge valuations to arise despite the technological feats involved

Helion should survive the imminent collapse of OpenAI but Moore's Law suggests power demands from AI aren't going to keep going up forever

[jrvz]

For fusion propulsion, you might look at the report "Fusion-Enabled Pluto Orbiter and Lander" https://www.nasa.gov/wp-content/uploads ... tagged.pdf by Stephanie Thomas. She estimated "2.5 to 5 N of thrust for each megawatt of fusion power, reaching a specific impulse, Isp, of about 10,000 s...Our point solution for the Pluto mission now delivers 1000 kg of payload to Pluto orbit in 3.75 years using 7.5 N constant thrust. This could potentially be achieved with a single 1 MW engine."

This was based on the Princeton Field-Reversed Configuration (PFRC) fusion reactor under development at the Princeton Plasma Physics Laboratory. Several people from there later started Helion.

[jrvz]

Or: The concept in "Nuclear propulsion through direct conversion of fusion energy: The fusion driven rocket" by Slough, Pancotti, Kirtley, Pihl, and Pfaff https://ntrs.nasa.gov/api/citations/201 ... 010608.pdf uses a pulsed fusion machine more similar to Helion's machine but with a lithium liner that is used to compress the FRC and is accelerated for thrust. They suggest an Isp between 2440 and 5720 s, and a rocket with a crew habitat of 61,000 kg and total mass of 135,000 kg capable of a 90 day transit to Mars.