ZAP Energy News

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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mvanwink5
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Re: ZAP Energy News

Post by mvanwink5 »

ZAP has a new paper on Q determination:
(Go to Link for full paper.)
Fusion Gain and Triple Product for the Sheared-Flow-Stabilized Z Pinch
https://www.tandfonline.com/doi/full/10 ... 23.2198049
Abstract
Formulae display:MathJax Logo?

Fusion gain Q
and triple product nTτ are derived for the sheared-flow-stabilized (SFS) Z pinch by including the input power associated with driving the plasma flow and the additional advective loss of thermal energy. Plasma impurities contribute to radiative power losses and to thermal power losses by increasing the electron population. The presence of impurities increases the required plasma parameters, characterized by the triple product, to achieve fusion gain. The analysis is applied to deuterium-tritium (D-T) fusion, though the methodology can be extended to other reactions. Since D-T fusion produces an alpha particle, the possibility exists of magnetically confining the alpha with sufficiently high magnetic fields, which are self-generated by the plasma pinch current. Confined alpha particles can heat the D-T fusion fuel, reduce the needed input power, and thereby amplify the fusion gain. However, ignition (Q→∞) does not occur since the axial plasma flow must be externally driven. The impacts of alpha heating and impurity losses are considered on the fusion performance of the SFS Z pinch. Requirements, assumptions, and limitations are described that would justify a determination of “D-T equivalent Q=1 conditions” in a D-D plasma. A minimum set of experimental measurements of plasma parameters is specified that can be compared to a plasma parameter map to facilitate a “Q=1” claim, where Q is defined by instantaneous values of fusion power and input power. Corroborating measurements are also discussed that would further support extrapolation of plasma and fusion performance to D-T operation.
Counting the days to commercial fusion. It is not that long now.

mvanwink5
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Re: ZAP Energy News

Post by mvanwink5 »

From ZAP:
The paper has been peer-reviewed and we look forward to further feedback from the fusion community, a necessary and important step before we can share Q performance results.
One might speculate that ZAP has performance results that they want to report...
Counting the days to commercial fusion. It is not that long now.

sdg
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Joined: Tue Jul 01, 2008 8:17 pm

Re: ZAP Energy News

Post by sdg »

mvanwink5 - you beat me to it! Thanks for posting.
More great news!
Here's a follow up article citing the above journal article, for targeting the lay audience:
https://scitechdaily.com/zap-energy-unv ... ergy-gain/

Skipjack
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Re: ZAP Energy News

Post by Skipjack »

I am very bullish on Zap. I think they have a real shot at this. Plus their design is very compact and it might make for an amazing space propulsion system.

mvanwink5
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Re: ZAP Energy News

Post by mvanwink5 »

Plus their design is very compact and it might make for an amazing space propulsion system.
SJ, what method of propulsion? At this point their conversion approach is thermal.
Counting the days to commercial fusion. It is not that long now.

Giorgio
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Re: ZAP Energy News

Post by Giorgio »

mvanwink5 wrote:
Tue Jun 06, 2023 8:11 am
Plus their design is very compact and it might make for an amazing space propulsion system.
SJ, what method of propulsion? At this point their conversion approach is thermal.
It's pretty straightforward, just let part of the fusion plasma out to act as propulsion.
There was a paper from Shumlak on this in the early 2000, should be easy to find online, in case you are interested I can send a link to you.
A society of dogmas is a dead society.

mvanwink5
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Re: ZAP Energy News

Post by mvanwink5 »

Yes, here is an abstract of a paper:
https://pennstate.pure.elsevier.com/en/ ... z-pinch-fu
Abstract
A fusion space thruster based on the flow-stabilized Z-pinch may be possible in the near-term and provide many advantages over other fusion-based thruster concepts. The Z-pinch equilibrium is classically unstable to gross disruption modes according to theoretical, numerical, and experimental evidence. However, a new stabilization mechanism has been discovered that can stabilize these modes with plasma flow. The stabilizing mechanism was developed for a Z-pinch plasma equilibrium which has an axial velocity profile that is linear in radius. When the velocity shear exceeds a threshold, the plasma modes are stabilized. The magnitude of the peak velocity is dependent on the mode wavelength but is sub-Alfvénic for the wavelengths of experimental interest, vmax > 0.1VAka where VA is the Alfvén speed, k is the axial wave vector, and a is the characteristic pinch radius. The flow Z-pinch experiment ZaP has been built at the University of Washington to experimentally verify the sheared flow stabilizing mechanism. The experiment has achieved plasma flow velocities of 10**5 m/s and stability for almost 2000 growth times. For more information the reader is encouraged to visit http://www.aa.washington.edu/AERP/ZaP. The extension of the flow Z-pinch to a space thruster is straight forward. The plasma in a flow Z-pinch would already be moving axially, fusing, and releasing a tremendous amount of nuclear energy. The end of the Z-pinch can be left open to allow the escape of the energetic plasma. Specific impulses in the range of 10**6 s and thrust levels of 10**5N are possible.
Counting the days to commercial fusion. It is not that long now.

Skipjack
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Re: ZAP Energy News

Post by Skipjack »


Giorgio
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Re: ZAP Energy News

Post by Giorgio »

Yes, that's the one.
A society of dogmas is a dead society.

Skipjack
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Re: ZAP Energy News

Post by Skipjack »

This is from back in February. Some interesting details in there:
https://www.pppl.gov/events/2023/pppl-c ... ion-energy

RERT
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Re: ZAP Energy News

Post by RERT »

In the slide ‘Performance scaling of SFS fusion’ in Ben Leavitt’s talk, Fuze-Q was underperforming Fuze at the same current. I don’t know if that has any bearing on my earlier comment, but quite interesting.

Skipjack
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Re: ZAP Energy News

Post by Skipjack »

RERT wrote:
Wed Jun 07, 2023 8:48 pm
In the slide ‘Performance scaling of SFS fusion’ in Ben Leavitt’s talk, Fuze-Q was underperforming Fuze at the same current. I don’t know if that has any bearing on my earlier comment, but quite interesting.
Early stages. They are still optimizing the thing. Lots of knobs to turn there before it will be at full performance.

RERT
Posts: 271
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Re: ZAP Energy News

Post by RERT »

I posted a question on their contact page.

You may well be right, but it has the feel of a bad surprise for them.

mvanwink5
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Location: N.C. Mountains

Re: ZAP Energy News

Post by mvanwink5 »

Does not sound like a surprise because it was stated in SJ's linked video that the reason for current FuZE-Q performance is that it has not been optimized yet. Past devices obviously needed optimization also.

I thought it was interesting that contaminants and their spectral lines were used to measure temperature & they were looking for other techniques as they go for higher temperatures.

ZAP is in the science phase with their approach, but they are pushing hard & their work is facilitated due to the small device size & simplicity of basic device configuration. Indeed, such things as power supply are nearly off the shelf and it only took a couple of months to get the mega amp supply up & running (albeit hard work & burning midnight oil). Contrast ZAP's design & build requirements to General Fusion with their fusion vessel, LOL.
Counting the days to commercial fusion. It is not that long now.

Munchausen
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Re: ZAP Energy News

Post by Munchausen »


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