New records on Wendelstein 7-X • Hacker News Board

Re: New records on Wendelstein 7-X

#21

Post by LeifCarrotson » Mon, Jul 21, 2025, 4:24 PM UTC

apples_oranges wrote: post #3

Looking at the picture, I wonder if complexity of these devices will significantly be reduced once it finally works. I assume a lot of the bells and whistles are needed to find the way, but once it's found..

In my experience doing plumbing/hydraulics/pneumatics for industrial equipment, the first generation of a new product always looks way more complex than later versions. But I'm not sure they're actually more complex, they're often using a smaller variety of more flexible "industrial Lego" rather than custom, unique parts that are harder to extend or modify.

Yeah, a single welded tube of the right diameter that necks down just so in that one spot to prevent cavitation, which has that sweeping multi-planar bend to just barely sneak through that obstruction, will look neat and tidy to a casual observer. Conversely, a stack of triclamp flanges, a straight length of pipe that shoots way out away from the guts of the equipment before it jogs sideways and down and back in with 90 degree couplings and gaskets and a manual shut-off valve and a pressure transmitter/flow meter and a "T" with a cap (just in case) and a sight glass looks like an awful mess.

But I can build the latter in half an hour with parts we have on hand. And I'm not even a fitter, I'm an engineer! And when you do want to add something to it, I can do that in 5 minutes. After observing it function through the full regime of pressure and flow and viscosity parameters the equipment might have to deal with, I can maybe generate a print for the real plumbers to build the former dedicated-purpose component that sets all the constraints in stone (or rather, in welded stainless). That part will be unique and inflexible, embedding all the restrictions and history and test results and design decisions into a component that looks deceptively smooth to a layman's eyes.

Is that simpler? I suppose it depends on your perspective.

Re: New records on Wendelstein 7-X

#22

Post by pama » Mon, Jul 21, 2025, 4:25 PM UTC

bradleyy wrote: post #12

In any future fusion power plant, a plasma with a high triple product must be maintained for long periods. I love vague terms like "long periods". Long compared to the Planck length? Geological time? Is the advertised 43 seconds almost there or "off by 17 orders of magnitude?"

I agree vague language in popular press is sometimes annoying.

“Off by 17 orders of magnitude” would be off by 136 billion years, so not that much for sure. Assuming you want to be able to test the plant and or maintain it once per year, 43 seconds is less than 6 orders of magnitude off. The jump was more than a full order of magnitude compared to past records, so another handful such developments and we are there.

Re: New records on Wendelstein 7-X

#23

Post by empath75 » Mon, Jul 21, 2025, 4:26 PM UTC

apples_oranges wrote: post #3

Looking at the picture, I wonder if complexity of these devices will significantly be reduced once it finally works. I assume a lot of the bells and whistles are needed to find the way, but once it's found..

The real problem with fusion power is that even if they figure it out, it still won't be cost competitive with solar and wind.

Economically all the cost of building a "boil some water and turn some turbines" plant is _already_ in the "boiling some water and turning some turbines" part of the generation, and even if the heat part of it was _free_, the rest of it would be too expensive to bother building a plant for it, compared to just building solar and wind generation and some better batteries.

Re: New records on Wendelstein 7-X

#24

Post by soperj » Mon, Jul 21, 2025, 4:27 PM UTC

bhaak wrote: post #9

ortusdux wrote: post #8

Earlier quoted context omitted.

I'm not keen on the idea of applying a 'keep subtracting things until it blows up' mentality to fusion reactors.

The nice thing about fusion reactors is that they don’t blow up but just don’t work anymore.

they have fission reactors that have done that since the 60s (CANDU Reactor). They just don't help you produce nuclear bombs...

Re: New records on Wendelstein 7-X

#25

Post by cjbgkagh » Mon, Jul 21, 2025, 4:28 PM UTC

GMoromisato wrote: post #20

ortusdux wrote: post #8

Earlier quoted context omitted.

I'm not keen on the idea of applying a 'keep subtracting things until it blows up' mentality to fusion reactors.

You could probably summarize the history of bridge-building as "keep subtracting things until they don't stand up anymore." Building bridges (and large structures in general) has always been about the tension between over-engineering (for safety) and under-engineering (for cost/aesthetics). The Brooklyn Bridge is massive; they'd never built a bridge like that so they over-engineered it. But once they saw that it was…

Not read the book but I thought the Brooklyn Bridge was over specified on the wire strength because they knew the corrupt supplier would circumvent quality control to supply them with substandard material.

Re: New records on Wendelstein 7-X

#26

Post by tgtweak » Mon, Jul 21, 2025, 4:28 PM UTC

This article has zero quantifiable information in it aside from the duration... which has no context. Who's recordkeeping this stuff? What are the other results so far? What is the tipping point where it is net positive? how long does it need to sustain a net positive fusion reaction to produce sufficient power for grid consumption? Are there other losses (thermal generation inefficiencies) that make the target even farther than energy-in<energy-out?

Re: New records on Wendelstein 7-X

#27

Post by drob518 » Mon, Jul 21, 2025, 4:29 PM UTC

GMoromisato wrote: post #20

ortusdux wrote: post #8

Earlier quoted context omitted.

I'm not keen on the idea of applying a 'keep subtracting things until it blows up' mentality to fusion reactors.

You could probably summarize the history of bridge-building as "keep subtracting things until they don't stand up anymore." Building bridges (and large structures in general) has always been about the tension between over-engineering (for safety) and under-engineering (for cost/aesthetics). The Brooklyn Bridge is massive; they'd never built a bridge like that so they over-engineered it. But once they saw that it was…

When I was an engineering summer intern at HP, they had all the interns do a side project of building a bridge (model sized). The designs would be judged by stacking bricks on the bridges and then dividing the max count of bricks before failure by the weight of the bridge. Most interns, myself included, over engineered our designs. One intern “got it” and submitted a bridge that was built out of just a few pieces of balsa wood. It only held one or two bricks before snapping, but it was ultra-light and won the competition. That exercise always stayed with me. Engineers always need to focus on the correct priorities and understand when “enough is enough.”

Re: New records on Wendelstein 7-X

#28

Post by rnhmjoj » Mon, Jul 21, 2025, 4:34 PM UTC

bradleyy wrote: post #12

In any future fusion power plant, a plasma with a high triple product must be maintained for long periods. I love vague terms like "long periods". Long compared to the Planck length? Geological time? Is the advertised 43 seconds almost there or "off by 17 orders of magnitude?"

Long compared to the current generation of experiments. JET pulses lasted a couple of seconds, an actual power plant might be more like a couple of hours or even a steady-state.

Re: New records on Wendelstein 7-X

#29

Post by HPsquared » Mon, Jul 21, 2025, 4:34 PM UTC

LeifCarrotson wrote: post #21

apples_oranges wrote: post #3

Looking at the picture, I wonder if complexity of these devices will significantly be reduced once it finally works. I assume a lot of the bells and whistles are needed to find the way, but once it's found..

In my experience doing plumbing/hydraulics/pneumatics for industrial equipment, the first generation of a new product always looks way more complex than later versions. But I'm not sure they're actually more complex, they're often using a smaller variety of more flexible "industrial Lego" rather than custom, unique parts that are harder to extend or modify. Yeah, a single welded tube of the right diameter that necks…

It's a bit like interpreted code vs optimized machine code.

Re: New records on Wendelstein 7-X

#30

Post by HPsquared » Mon, Jul 21, 2025, 4:36 PM UTC

grues-dinner wrote: post #18

xorxornop wrote: post #11

Earlier quoted context omitted.

I wouldn't be concerned about this, personally, for the precise reason that it is a fusion device - not fission! Fusion is incredibly difficult just to start, let alone keep burning - unlike fission, which is only too happy to enter runaway conditions if not very carefully regulated. Fusion is like a little ember in your fireplace you have to carefully blow on to keep alight; fission is like keeping a fireplace lit b…

I'd say (older-generation) fission is more like having an indoor swimming pool filled with burning gasoline, but keeping the windows shut so there's only enough air for it to burn at the rate you want to heat the house.

Or a swimming pool full of those spicy rocket propellents discussed in the book Ignition! which have combustion products like hydrogen fluoride.