[phpBB Debug] PHP Warning: in file [ROOT]/phpbb/session.php on line 594: sizeof(): Parameter must be an array or an object that implements Countable
[phpBB Debug] PHP Warning: in file [ROOT]/phpbb/session.php on line 650: sizeof(): Parameter must be an array or an object that implements Countable
[phpBB Debug] PHP Warning: in file [ROOT]/phpbb/session.php on line 1110: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3903)
[phpBB Debug] PHP Warning: in file [ROOT]/phpbb/session.php on line 1110: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3903)
[phpBB Debug] PHP Warning: in file [ROOT]/phpbb/session.php on line 1110: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3903)
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 494: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 113: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 113: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 113: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 113: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 113: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 5277: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3903)
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 5277: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3903)
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 5277: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3903)
Talk-Polywell.org • Spherical Tokamaks
Page 1 of 2

Spherical Tokamaks

Posted: Wed Aug 12, 2015 7:36 am
by crowberry
The Spherical Tokamak (ST) is a hot topic because it seems to have favourable stability properties compared to a traditional tokamak and in addition to that the additional benefits of smaller size, faster development cycles and lower cost. Dennis Whyte of MIT has been promoting the ST design called Affordable Replacable Compact (ARC). MIT has a new press release on ARC:


Here is the latest paper (paywalled) about the ARC design:

I expect to hear a lot more about Spherical Tokamaks in the next few years. I would not be too surprised to see a company being formed around ARC in a similar way as the UK based Tokamak Energy is working on their own High Temperature Superconductor designs.

Re: Spherical Tokamaks

Posted: Wed Aug 12, 2015 4:18 pm
by Skipjack

Re: Spherical Tokamaks

Posted: Wed Aug 12, 2015 5:59 pm
by Giorgio

Re: Spherical Tokamaks

Posted: Thu Aug 13, 2015 3:43 am
by Tom Ligon
Dr. Bussard liked spheromaks. We had a visit from Paul Koloc one day, where they discussed their ideas for fusion. Paul was using spheromaks as a model for ball lightning at that point. Essentially, a spheromak's shape is so natural for the magnetic fields that it can exist without the physical machine.

Re: Spherical Tokamaks

Posted: Thu Aug 13, 2015 1:56 pm
by Skipjack
I definitely like it better than other tokamaks. I wonder how favorably it compares to the Dynomak from the UW.
Still, it only doing T+D which means you have all the problems coming with that. I believe (but I am not sure), that the Dynomak can theoretically do D+D/He3 (though they will have T+D side reactions due to being steady state).

Re: Spherical Tokamaks

Posted: Fri Aug 21, 2015 5:02 pm
by TheRadicalModerate

Re: Spherical Tokamaks

Posted: Fri Aug 21, 2015 6:14 pm
by Solo
You have to read between the lines a bit to understand this proposal. MIT is going to be forced to shut down C-Mod, their high-field tokamak. They would like to continue by building a new, higher-field tokamak. I'd give both this and the dynomak a snowball's chance in hell of being built in the current funding climate though. The ARC design is pretty much a Hail Mary pass. That doesn't mean it's not a good idea though, just that most ideas, even good ones, are not going to get funding right now. Not from the Fedigov at any rate.

Re: Spherical Tokamaks

Posted: Sat Aug 22, 2015 8:08 am
by Skipjack

Re: Spherical Tokamaks

Posted: Sat Aug 22, 2015 4:41 pm
by hanelyp
The conservative political position asks why taxpayers should pay for something or government should pick winners and losers, energy research in this case.

The current putz occupying the White House has policies consistent with wanting energy poverty, and using energy policy to launder money to cronies.

Re: Spherical Tokamaks

Posted: Mon Aug 24, 2015 6:25 pm
by swamijake
Not sure how this discussion is relevant to the topic. From what I can glean, the spherical tokamak is a similar to a regular tokamak except the central portion of the toroid magnets is shared by all the segments. Some designs have this central pole basically exposed to plasma.

Apparently the skinnier you can make that central pole the better the stability. Not sure how you heat the plasma as effectively as this eliminates the inner poloidal coils, but I suppose you can just blast it with RF or neutral beam injection.

Its a bit confusing as Spheromak is an entirely different entity. If you peeled an orange and stuck a pencil down the center it would look pretty close to a Spherical Tokamak, so maybe we can call it the Orange-o-mak?

Re: Spherical Tokamaks

Posted: Tue Oct 25, 2016 7:44 pm
by crowberry
The NSTX-U has unfortunately a malfunctioning magnet, which can take up to a year to fix.

Re: Spherical Tokamaks

Posted: Mon Sep 17, 2018 3:48 pm
by crowberry

Re: Spherical Tokamaks

Posted: Sun Aug 18, 2019 6:53 am
by crowberry
NSTX-U will be repaired with tighter tolerances to improve the performance:

Re: Spherical Tokamaks

Posted: Sun Aug 18, 2019 10:19 am
by Giorgio
It took 4 years to complete the upgrade, 3 years to pinpoint the issues after the upgrade, and who know how many more years will pass before (if) they will complete the renewal.
We can easily say that at least 10 years will elapse from when the machine was lastly used to when it will produce again some scientific data.

Not a good news for anyone...

Re: Spherical Tokamaks

Posted: Sun Aug 18, 2019 5:23 pm
by Skipjack
Meanwhile Tokamak Energy is ready to run their upgraded machine.