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Progress toward fusion energy gain as measured against the Lawson criteria

fusionenergybase.com

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Re: Progress toward fusion energy gain as measured against the Lawson criteria

#51

Post by westurner »

analog31 wrote: post #47
dale_glass wrote: post #34

It should be noted that "breakeven" is often misleading. There's "breakeven" as in "the reaction produces more energy than put into it", and there's breakeven as in "the entire reactor system produces more energy than put into it", which isn't quite the same thing.

In the laser business, the latter is called "wall plug efficiency," which is laser power out per electrical power in.

"Uptime Percentage", "Operational Availability" (OA), "Duty Cycle"

Availability (reliability engineering) https://en.wikipedia.org/wiki/Availability

Terms from other types of work: kilowatt/hour (kWh), Weight per rep, number of reps, Total Time Under Tension

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#52

Post by trhway »

CGMthrowaway wrote: post #15

I heard that NIF was never intended to be a power plant, not even a prototype of one. It's primarily a nuclear weapon research program. For a power plant you would need much more efficient lasers, you would need a much larger gain in the capsules, you would need lasers that can do many shots per second, some automated reloading system for the capsules, and you would need a heat to electricity conversion system around…

ASML machine with "s/tin/DT/" looks like a prototype of such a reactor and of a fusion space drive.

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#53

Post by stshank »

twothreeone wrote: post #37
sam wrote: post #14

Earlier quoted context omitted.

Companies like Commonwealth Fusion Systems are an example of those utilizing high-temperature superconductors which did not exist commercially when ITER was being designed.

ITER uses HTSs, just not for the coils: > The design operating current of the feeders is 68Ka. High temperature superconductor (HTS) current leads transmit the high-power currents from the room-temperature power supplies to the low-temperature superconducting coils 4K (-269°C) with minimum heat load. Source: https://www.iter.org/machine/magnets

HTS current feeds are a good idea (we also use them at CFS, my employer: https://www.instagram.com/p/DJXInDUuDAK/). It's HTS in the coils (electromagnets) that enables higher magnetic fields and thus a more compact tokamak.

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#54

Post by trhway »

hinkley wrote: post #35
DennisP wrote: post #16

Earlier quoted context omitted.

It's an experimental facility. Yes, a power plant would need much more efficient lasers, but NIF's lasers date back to the 1990s, equivalent modern lasers are about 40X more efficient, and for an experiment it's easy enough to do a multiplication to see what the net result would have been with modern lasers. Modern lasers can also repeat shots much more quickly. Power gain on the capsules appears to scale faster than…

I was trying to work out a joke about buying better lasers off of alibaba but it seems that despite being 30 years old they're still orders of magnitude beyond off the shelf options.

partially. The very efficient lasers from alibaba don't have short pulse/high power, so they can potentially be used only as the part of the system - the pumping lasers. The final nanosecond-laser is still a one-off build which though seems to be pretty doable even by a small company if they set their mind to it.

Btw, NIF achieved those recent results by adding strong magnetic field around the target (penny-shrinkers knew that tech for 20+ years :). There are other things like this around that can potentially be similarly useful. Only if somebody had money and interest ...

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#56

Post by kristianp »

dale_glass wrote: post #34

It should be noted that "breakeven" is often misleading. There's "breakeven" as in "the reaction produces more energy than put into it", and there's breakeven as in "the entire reactor system produces more energy than put into it", which isn't quite the same thing.

The article uses the term "scientific breakeven" which I assume is the first one you've stated.

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#57

Post by triceratops »

arghandugh wrote: post #20
thinkingtoilet wrote: post #18

Earlier quoted context omitted.

If the alternative option is a coal power plant, sign me up!

You will not live long enough to see commercial fusion power, and your children will not live long enough to see a complete end to thermal coal.

I don't know I think thermal coal could end in my lifetime.

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#58

Post by pfdietz »

DennisP wrote: post #50
dale_glass wrote: post #31

Earlier quoted context omitted.

I'm a different person, but I tend to agree. ITER began building in 2013, first plasma is expected for 2034. DEMO is expected to start in 2040. So, ITER is taking an estimated 20 years. It's being built for a reason, so I imagine follow-ups want to wait to see how that shakes out. So certainly, DEMO needs to start a few years after ITER is finally done. Then DEMO isn't a production setup either, it's going to be the…

ITER/DEMO is an exceptionally slow fusion project and arguably obsolete since it uses older superconductors. CFS uses the same design, with modern superconductors that can support much stronger magnetic fields. Tokamak output scales with the fourth power of magnetic field strength, so this should let them get results similar to ITER in a reactor a tenth the size. They'll have it running long before ITER is ready.

ITER will have 400x lower power density than a PWR.

ARC, which uses those high temperature superconductors, is just 40x lower power density.

Neither promises to be competitive with fission, never mind the things beating fission.

Re: Progress toward fusion energy gain as measured against the Lawson criteria

#59

Post by pfdietz »

greenavocado wrote: post #45
BizarroLand wrote: post #32

Earlier quoted context omitted.

I mean, yes, you're right, but it's not a permanently radioactive waste. Quote: A fusion power plant produces radioactive waste because the high-energy neutrons produced by fusion activate the walls of the plasma vessel. The intensity and duration of this activation depend on the material impinged on by the neutrons. The walls of the plasma vessel must be temporarily stored after the end of operation. This waste quan…

The amount of radioactive scrap produced by hypothetical decommissioned radioactive fusion containment vessels is laughably trivial compared to fission waste streams. Even accounting for the most pessimistic irradiation models of first-wall materials, the total radioactive burden remains orders of magnitude below legacy technologies. The half-lives of such activated components like predominantly steel alloys and cera…

The long term activity of the waste is certainly lower, but the volume of the waste is likely much higher. And much of the cost is driven by volume, not activity.
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