Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

ipp.mpg.de

Post reply on HN
Print view View original

11–20 of 322 posts

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#11

Post by aeyes »

KyleBerezin wrote: post #7
barbazoo wrote: post #4

Earlier quoted context omitted.

> the wendelstein 7x is never going to generate usable electricity What's the reason for that?

We are researching fusion technology. It would take a reactor many times larger to get more energy out of the facility than you put in. The technology still needs to mature before a reactor that size would be financially responsible.

In the German Alternativlos podcast the Wendelstein team (Prof. Dr. Thomas Klinger, Dr. Adrian von Stechow) recently stated that it is already feasible, they estimate a cost of ~€20B and a 5 year construction time for a commercial fusion power plant if we started now.

https://alternativlos.org/51/

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#12

Post by gabereiser »

white_dragon88 wrote: post #10
KyleBerezin wrote: post #3

Ahh, Wendelstein is that stellerator reactor. The stellerator is really cool, and an alternative to a tokamak reactor. Tokamak is the doughnut shaped reactor, and it has a problem where the plasma near the outer circumference has less magnetic confinement. The stellerator is similar, but confines the plasma to a ribbon and folds it over on itself in a mobius-like arrangement. I used to be really interested in this, b…

You know enough to say more. Say more!

Seconded. This is fascinating stuff and reminds me of some crazy rant some guy was telling me about anti-gravity and how electromagnetic “ribbons” could propel you. Obviously the guy was nuts, right? How would one go about learning more about electromagnetic plasma containment folding?

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#13

Post by YossarianFrPrez »

If I understand things correctly, the problem with magnetic confinement (e.g. Tokomaks, Stellarators) is that once you have heated a plasma such that it is "fusing," how do you get the power out with out cooling the very plasma you've just spent a lot of energy heating up?

Helion, a fusion startup, claims to have solved this problem via capturing an induced current from colliding two hot plasmas together. I'd be curious if there is any way the Wendelstein can produce electricity.

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#14

Post by lostlogin »

KyleBerezin wrote: post #3

Ahh, Wendelstein is that stellerator reactor. The stellerator is really cool, and an alternative to a tokamak reactor. Tokamak is the doughnut shaped reactor, and it has a problem where the plasma near the outer circumference has less magnetic confinement. The stellerator is similar, but confines the plasma to a ribbon and folds it over on itself in a mobius-like arrangement. I used to be really interested in this, b…

Are you able to say more about what you do? Judging by your comments, you have some idea what you are talking about.

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#15

Post by ethbr0 »

barbazoo wrote: post #4
foolfoolz wrote: post #2

i’ve been following this project for 10 years. it’s been successful. but how do projects like these move faster? the wendelstein 7x is never going to generate usable electricity. it’s supposed to be the pre cursor to the producing reactor

> the wendelstein 7x is never going to generate usable electricity What's the reason for that?

tl;dr - Output nuclear fusion power, plasma volume, and magnetic field strength scale differently with reactor size increases

In detail, I'll let someone smarter than me in nuclear physics explain: https://physics.stackexchange.com/questions/175830/nuclear-f...

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#16

Post by snarkconjecture »

aidenn0 wrote: post #8

What is "energy turnover" in this usage? [edit] Found it: "Energy turnover is defined as the amount of heat multiplied by the duration of the discharge[1]." By "amount of heat" I assume they mean "heating power delivered to the plasma" b/c the the only way to multiply by time and get Joules is to start with power. 1: https://gigazine.net/gsc_news/en/20230227-wendelstein-7-x-en...

Yes, it's a little buried but the article says

> The energy turnover results from the coupled heating power multiplied by the duration of the discharge

The numbers:

> The energy turnover of 1.3 gigajoule was achieved with an average heating power of 2.7 megawatts, whereby the discharge lasted 480 seconds

Also:

> Within a few years, the plan is to increase the energy turnover at Wendelstein 7-X to 18 gigajoules, with the plasma then being kept stable for half an hour

i.e. 10 megawatts for 30 minutes

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#17

Post by Tuna-Fish »

YossarianFrPrez wrote: post #13

If I understand things correctly, the problem with magnetic confinement (e.g. Tokomaks, Stellarators) is that once you have heated a plasma such that it is "fusing," how do you get the power out with out cooling the very plasma you've just spent a lot of energy heating up? Helion, a fusion startup, claims to have solved this problem via capturing an induced current from colliding two hot plasmas together. I'd be curi…

Most fusion power systems assume they are doing that as neutrons. D-T fusion conveniently has the proportion of energy that gets lost from the plasma as KE of neutrons be pretty close to the amount of energy that a conveniently sized fusion reactor can afford to remove from the plasma.

Then you trap the neutrons with, for example, a lithium blanket, use them to breed more tritium, and produce energy with a turbine from the heating of the blanket.

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#18

Post by KyleBerezin »

aeyes wrote: post #11
KyleBerezin wrote: post #7

Earlier quoted context omitted.

We are researching fusion technology. It would take a reactor many times larger to get more energy out of the facility than you put in. The technology still needs to mature before a reactor that size would be financially responsible.

In the German Alternativlos podcast the Wendelstein team (Prof. Dr. Thomas Klinger, Dr. Adrian von Stechow) recently stated that it is already feasible, they estimate a cost of ~€20B and a 5 year construction time for a commercial fusion power plant if we started now. https://alternativlos.org/51/

Yea, but compare the financial burden of that compared to a solar farm of the same output. Not to mention the technical risk.

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

#19

Post by TaylorAlexander »

Speaking of fusion does anyone know what is going on with SPARC at Commonwealth Fusion Systems? I have been very excited about their system but they are understandably in a deep development and construction cycle after a $2B investment, so all their news page has for the last year are updated business deals and awards. I would love to hear how reactor construction is going.
Post reply on HN