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Re: MIT claim they will build the SPARC

Posted: Tue Sep 29, 2020 7:38 pm
by crowberry
Brandon Sorbom, Commonwealth Fusion Systems will give a MIT PFSC seminar ARC and the path to high field fusion on Oct 9, 2020 12:30 PM Eastern Time (US and Canada) https://www.psfc.mit.edu/events/2020/ar ... eld-fusion.

Re: MIT claim they will build the SPARC

Posted: Tue Sep 29, 2020 11:37 pm
by Skipjack
Their seven papers are available for open access here:
https://www.cambridge.org/core/journals ... sics-basis

Re: MIT claim they will build the SPARC

Posted: Thu Oct 01, 2020 11:05 pm
by Skipjack
Giorgio wrote:
Thu Oct 01, 2020 3:23 pm
Skipjack wrote:
Thu Oct 01, 2020 12:23 pm
I don't think that the MIT sees any show stoppers for going forward with SPARC. I am a bit confused why you think they could not?
My concern is not that there is a "design" show stopper from the physics side, but engineering design for components like the divertor are simply not yet mature to be used in a commercial reactor or even to make full use of the actual test possibilities offered by the new superconductors in research reactors like SPARC.
And no one is putting "real" effort and money to overcome these limits.


I will take few examples from the very same papers that they are going to be presented in the coming APS meeting:

http://meetings.aps.org/Meeting/DPP20/Session/JO08.13
"The divertor heat flux problem is an important unresolved dilemma facing future reactor-level fusion devices. "


http://meetings.aps.org/Meeting/DPP20/Session/JO08.12
"Based on empirical scalings, the peak unmitigated divertor parallel heat flux in SPARC is projected to be greater than 10 GW/m2"
(Our best technology (for ITER) is now on the range of 20 MW/m2.)


http://meetings.aps.org/Meeting/DPP20/Session/JO08.15
"Fusion power fundamentally has two limits: core plasma pressure must reside within tokamak operation limits and plasma heat exhaust must be within technology limits."
(This paper also evaluates fusion power limits with with actual TRL (and by sacrificing some other factors) and sets it to 2GW fusion power. This should be an interesting paper to read if they will publish it.)
Moving this debate over from the Z- Pinch thread:
The Divertor design paper is available to the public already (along with the other papers above):
https://www.cambridge.org/core/journals ... ore-reader

There clearly are some uncertainties but they are trying to mitigate the problem a bit with the relatively short plateau of 10 seconds:

Re: MIT claim they will build the SPARC

Posted: Fri Oct 02, 2020 8:28 am
by Giorgio
Thanks for the links, I saw them from your previous post but I didn't notice that they was including also some of the papers of the coming APS presentation.
I will check them thoroughly during weekend relax time, but a a first quick read has given me the impression that the design didn't change much from last papers I read.
They are still going for a 20-30MW/m2 divertor and plan to limit its irradiation at ~1 sec over a 10/15 seconds total shot time to prevent the divertor from melting. It's a solution that might work to make experimental shots, but is not a solution for a commercial or demonstration reactor. Kinda like having an electric generator and turning it on and off every 10 seconds to prevent cylinder meltdown......

The potential solution they are considering is still the XPT divertor design, but that will limit SPARC max Q to 2 and the total power to 2 GW, and anyhow no real experimental result has still been obtained on the XPT design in a SPARC environment, so this is still just a theoretical design proposal with several numerical simulations but no meaningful experiment has been planned to fully understand the limits and potential of evolution of this design before adding it to SPARC (at least as far as I know).

This (and several others issues) are rising my fear that research in heat generation based tokamak is reaching the point where it will hit a roadblock because we are focusing too much on how to make the reactor work (thanks to the latest superconductors improvements) but we are not focusing enough on how to properly manage it in a safe and efficient way once it works.

I will try to read everything over the weekend and see if anything new inside these papers from what was my last understanding.

Re: MIT claim they will build the SPARC

Posted: Sat Jan 30, 2021 6:31 am
by Munchausen
300 km of superconductor tape bought from SuperOX. Full text article available at Nature

https://www.nature.com/articles/s41598-021-81559-z

"Here we report a very high and reproducible JE in practical HTS wires based on a simple YBa2Cu3O7 (YBCO) superconductor formulation with Y2O3 nanoparticles, which have been delivered in just nine months to a commercial fusion customer in the largest-volume order the HTS industry has seen to date. "

Re: MIT claim they will build the SPARC

Posted: Fri Mar 05, 2021 1:26 pm
by crowberry
CFS has selected the site for SPARC and will start constructing in spring 2021. They plan to make their full scale magnet demonstration in June 2021:
https://cfs.energy/news-and-media/commo ... re-site-in

Re: MIT claim they will build the SPARC

Posted: Tue Apr 06, 2021 3:49 am
by Skipjack
Interesting presentation from "Developing a Regulatory Framework for Fusion Energy Systems".
CFS starts at page 76:
https://www.nrc.gov/docs/ML2109/ML21090A288.pdf
Some interesting tidbits on Tritium inventory and accident mitigation plans.

Re: MIT claim they will build the SPARC

Posted: Wed Sep 08, 2021 3:09 pm
by Carl White
"MIT-designed project achieves major advance toward fusion energy"
On Sept. 5, for the first time, a large high-temperature superconducting electromagnet was ramped up to a field strength of 20 tesla, the most powerful magnetic field of its kind ever created on Earth.
As a result, we are now well-prepared to ramp-up for SPARC production
https://news.mit.edu/2021/MIT-CFS-major ... nergy-0908

Re: MIT claim they will build the SPARC

Posted: Wed Sep 08, 2021 3:15 pm
by Skipjack
I was just about to post that :)

Re: MIT claim they will build the SPARC

Posted: Wed Sep 08, 2021 3:50 pm
by crowberry
This is interesting news. The question of radiation hardness of these HTC-magnets is still open. It will determine the lifetime of the magnets and the service interval and play a role in the operational costs of the facility, so it is an important issue.

Re: MIT claim they will build the SPARC

Posted: Sat Sep 11, 2021 10:23 am
by mvanwink5
Next Big Future has a new artlcle out on Commonwealth's fusion project. This type project is helping to drive the perception that fusion is 'maybe' rather than will be. Helion, General Fusion, TAE all have clear paths to energy extraction and fusion device longevity. Commonwealth does not.

https://www.nextbigfuture.com/2021/09/s ... gfuture%29

Re: MIT claim they will build the SPARC

Posted: Tue Oct 05, 2021 2:14 pm
by crowberry
This is a nice and well written article on the history of ARC, CFS and SPARC in the New Yorker by Rivka Galchen: Can Nuclear Fusion Put the Brakes on Climate Change?
https://www.newyorker.com/magazine/2021 ... ate-change

Re: MIT claim they will build the SPARC

Posted: Wed Dec 01, 2021 1:25 pm
by Skipjack
And CFS just raised 1.8 billion!
https://cfs.energy/news-and-media/commo ... es-b-round

Looks like this year is the big year for fusion. Incredible!

Re: MIT claim they will build the SPARC

Posted: Wed Dec 01, 2021 2:08 pm
by crowberry
Very good news indeed. The fusion race is really heating up!

Re: MIT claim they will build the SPARC

Posted: Wed Dec 01, 2021 2:17 pm
by Skipjack
I just hope that at least one of the companies succeeds before another one (inevitably) fails. I am quite certain that not all of them will make it, either technically or economically. But if at least one is already a success at that time, then it won't matter as much.