Z-Pinch Renaissance

[Munchausen]

Fresh article:

https://arxiv.org/pdf/1806.05894.pdf

[Skipjack]

Great find!

[Skipjack]

Looks like they are getting there. Goals for FuZE are:
Radius =1 mm, density: n = 2 ×10^24 m-3, temperature: 2500 to 4000 eV at an input current of 300 kA.
So far they are at 1–2 keV, and densities of approximately 10^17 cm3 with a radius of 3 mm. This is already a good improvement over ZAP- HD and it looks like they will reach their goals once they continue to increase the input current and tweaking the other parameters.
From what I understand, they halted increasing the current and focused on diagnostics at 200 kA. One focus was to determine whether the detected neutrons were indeed all thermonuclear in nature. From this paper it looks like this is the case. So to the best of my understanding, FuZE is still looking good.

[Skipjack]

7 papers on Uri Shumlak's Sheared Flow Stabilized Z- Pinch FuZE will be presented at the upcoming 60th Annual Meeting of the APS Division of Plasma Physics in November. Among them interesting topics like scaling the output up to reactor conditions and a paper on how it can be used as a propulsion system with high thrust and high Isp.

http://meetings.aps.org/Meeting/DPP18/Session/BM9.4
http://meetings.aps.org/Meeting/DPP18/Session/CP11.156
http://meetings.aps.org/Meeting/DPP18/Session/CP11.157
http://meetings.aps.org/Meeting/DPP18/Session/CP11.158
http://meetings.aps.org/Meeting/DPP18/Session/CP11.159
http://meetings.aps.org/Meeting/DPP18/Session/CP11.160
http://meetings.aps.org/Meeting/DPP18/Session/CP11.161
http://meetings.aps.org/Meeting/DPP18/Session/CP11.162
http://meetings.aps.org/Meeting/DPP18/Session/CP11.163
http://meetings.aps.org/Meeting/DPP18/Session/NI3.6

Updated the links above. It seems like schedule(?) changes messed up some of the links. Also seems like a couple of papers related to FuZE were added since the original post.

[Munchausen]

No renaissance this time! Back to the middle ages..

https://aip.scitation.org/doi/10.1063/1.5045123

Previously published calculations predict that the “staged z-pinch” (SZP) can achieve 400 MJ of fusion yield on a Z-class machine. The SZP is touted to need no external preheat mechanism and no external pre-magnetization method.

Our analyses and a review of the magnetized target parameter space leads to further conclusion that the SZP should not be considered to be a potential high-gain fusion source.

[Skipjack]

That's the "staged Z- Pinch", not the "Sheared Flow Stabilized Z- Pinch", big difference there.
Never had that high of an opinion of the former. The latter however... I had a really good conversation with Uri Shumlak a few months ago and it looks to the layman me like this has a lot of potential. So far they have met all their ARPA-E milestones (one of few participants to do so) and they are not _that_ far off from achieving break even either. Doubling the input current from the current prototype (which is "only the most straight forward of several knobs they can turn" according to Uri), seems relatively trivial.

[daveklingler]

Well now. The space propulsion paper with the exhaust velocities of 1 x 10^7 have just up and disappeared. Another paper has appeared in its place.

That's pretty disappointing. Once again, the absence of any proof proves the conspiracy is real.

[Skipjack]

Well now. The space propulsion paper with the exhaust velocities of 1 x 10^7 have just up and disappeared. Another paper has appeared in its place.

Strange indeed! Looks like some of the slots were replaced with the Staged Z- Pinch. Might just be a scheduling thing. There is an older (2006) paper on the use of a Sheared Flow Stabilized Z- Pinch as a space drive available for free here:
https://www.researchgate.net/publicatio ... on_Concept

Edit, the SFS- Z- Pinch based propulsion paper was indeed moved to another slot. Here is the new link:
http://meetings.aps.org/Meeting/DPP18/Session/CP11.163

Also seems like there were more SFS- Z- Pinch related papers added the schedule. I updated the original listings in my post above.

[Skipjack]

http://meetings.aps.org/Meeting/DPP18/Session/BM9.4
http://meetings.aps.org/Meeting/DPP18/Session/CP11.156
http://meetings.aps.org/Meeting/DPP18/Session/CP11.157
http://meetings.aps.org/Meeting/DPP18/Session/CP11.158
http://meetings.aps.org/Meeting/DPP18/Session/CP11.159
http://meetings.aps.org/Meeting/DPP18/Session/CP11.160
http://meetings.aps.org/Meeting/DPP18/Session/CP11.161
http://meetings.aps.org/Meeting/DPP18/Session/CP11.162
http://meetings.aps.org/Meeting/DPP18/Session/CP11.163
http://meetings.aps.org/Meeting/DPP18/Session/NI3.6

Updated the links to the papers related to the Sheared Flow Stabilized Z- Pinch and FuZE above. It seems like schedule(?) changes messed up some of the links. Also seems like a couple of papers related to FuZE were added since the original post.

[daveklingler]

Well now. The space propulsion paper with the exhaust velocities of 1 x 10^7 have just up and disappeared. Another paper has appeared in its place.

Strange indeed! Looks like some of the slots were replaced with the Staged Z- Pinch. Might just be a scheduling thing. There is an older (2006) paper on the use of a Sheared Flow Stabilized Z- Pinch as a space drive available for free here:
https://www.researchgate.net/publicatio ... on_Concept

Edit, the SFS- Z- Pinch based propulsion paper was indeed moved to another slot. Here is the new link:
http://meetings.aps.org/Meeting/DPP18/Session/CP11.163

Also seems like there were more SFS- Z- Pinch related papers added the schedule. I updated the original listings in my post above.

Thanks! Now to figure out how to get this month's paper so I can read it. The stated numbers are astounding.

Dave

[Skipjack]

Thanks! Now to figure out how to get this month's paper so I can read it. The stated numbers are astounding.

If you do find out, let me know. I want to read it too!

[Skipjack]

The Zap- Energy website has a small update:

We are delighted to announce that we’ve been awarded $6.8m ARPA-E OPEN 2018 funding.
Zap Energy is the most compact solution to fusion energy without complex and costly magnetic coils. We exceeded ARPA-E Alpha milestones in August
and our reactor is now consistently producing neutrons.

That sounds like good news! If they exceeded their milestones, that could mean that they are now at 300+ kA or about half way to break even.

Award text from ARPA-E- website:

Zap Energy will advance the fusion performance of the sheared flow stabilized ( SFS ) Z- pinch fusion concept.
SFS Z - pinch drives electrical current through a plasma to create magnetic fields that compress and heat the plasma toward fusion conditions.
Under this project, the team will raise the electrical current, reduce physics risks relating to plasma stability and confinement, and develop the electrode technology and plasma - initiation techniques necessary to enable the next steps toward a functional SFS Z - pinch fusion power plant.
This could provide nearly limitless, on - demand, emission - free energy with negligible fuel costs

[Skipjack]

Short presentation by Uri Shumlak at least year's ARPA-E Alpha Meeting:
Demonstrated Z- Pinch stability at 250 kA and continuous neutron production.
https://arpa-e.energy.gov/sites/default ... humlak.pdf

Also, they published a paper with their latest results:
https://arxiv.org/pdf/1806.05894.pdf

[Skipjack]

Small article about the Sheared Flow Stabilized Z- Pinch. Not much new in it, but still worth linking:
https://newatlas.com/nuclear-fusion-bre ... nch/59257/

[Ivy Matt]

I wonder what the relative difficulty/cost of getting fusion neutrons from a Z-pinch machine is compared to getting them from a Hirsch-Farnsworth fusor. Is there any other confinement concept for which the barrier to entry is as low (or nearly so) as the fusor? (An accelerator, perhaps, but that's not really a confinement concept.)