[HN Gopher] Wendelstein 7-X: 8 min Plasma with 1.3 GJ Energy Tur...
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Wendelstein 7-X: 8 min Plasma with 1.3 GJ Energy Turnover [video]
Author : croes
Score : 80 points
Date : 2023-02-24 14:33 UTC (8 hours ago)
(HTM) web link (www.youtube.com)
(TXT) w3m dump (www.youtube.com)
| mohmae45 wrote:
| hi
| mohmae45 wrote:
| Hi
| WithinReason wrote:
| Do I understand correctly that no actual fusion took place? This
| just heated the plasma using an external power source as a test.
| aqme28 wrote:
| I believe this was an experiment to see that they can put a lot
| of energy into the reactor, and take a lot of energy out of it
| as well. Both of these are necessary criteria for a power
| plant.
| mikeyouse wrote:
| Here's a related article explaining the most recent test;
|
| https://phys.org/news/2023-02-power-plasma-gigajoule-energy-...
| cstross wrote:
| Fusion reactor R&D generally _avoids_ actually starting a
| fusion reaction unless they 're ready to trash the reactor:
| current reactor designs can only manage D+T fusion, which
| generates a shitload of neutrons and leaves the reactor
| interior structures highly radioactive, making modification
| for further experiments problematic. (No-one is anywhere near
| achieving the energies needed for aneutronic fusion.)
|
| For example, the JET (Joint European Torus) Tokamak at Culham
| began operation in 1983 but experiments with tritium only
| started in 1991; maintenance and upgrades after 1998 relied
| on a remote handling system as it was no longer safe for
| human technicians to work inside the reactor containment in
| shutdown.
|
| https://en.wikipedia.org/wiki/Joint_European_Torus
| sp332 wrote:
| Polywell reactors have been doing D-D fusion since 2005,
| and measuring very few neutrons produced.
| foobiekr wrote:
| Is polywell dead? So little news.
| DennisP wrote:
| Lots of R&D uses deuterium, the neutron output is lower-
| energy and a handy diagnostic. Even hobbyists with fusors
| run on deuterium. Getting net power with deuterium is
| harder than D-T, but just fusing some deuterium isn't hard.
|
| The same goes for aneutronic fuels, as long as you reach
| the necessary temperature. Helion for example claims to
| have achieved a significant amount of D-He3 reactions.
| LPPFusion has published research saying they've achieved
| boron fusion temperatures, though not with boron fuel, or
| the triple product needed for net power from boron.
| (They're using deuterium though, and getting neutrons.)
| howenterprisey wrote:
| D-T definitely trashes the reactor, but D-D generates fewer
| neutrons, so human maintenance is generally OK afterwards.
| C-Mod at MIT ran this way for a while. You just needed to
| wear a dose meter.
| mikeyouse wrote:
| Small nit if you've never seen it written down, they're
| 'dosimeters'.
| pantalaimon wrote:
| Yes Wendelstein 7-X is not intended to produce fusion, it's an
| experiment to evaluate the stellarator concept.
| DennisP wrote:
| They do plan to fuel it with deuterium and run it over 100
| million degrees. They'll get fusion neutrons out of that.
| What they don't plan is deuterium-tritium fuel or a net power
| attempt.
|
| https://euro-fusion.org/devices/wendelstein-7-x/
| CodeWriter23 wrote:
| I'm no physicist, but I'm pretty sure presence of plasma in
| these gizmos indicates fusion. I think though you're asking if
| it was a self-sustaining reaction, and my impression (could be
| wrong) they did the ignition and they are stress testing the
| device and it's heating and cooling systems.
| aqme28 wrote:
| There are a lot of relatively cold plasmas that don't
| indicate fusion. Well, sure, maybe a few particles defy the
| odds and fuse, but really you're seeing basically none unless
| the heat and density get high enough.
| zardo wrote:
| Unless they mention fusion, they are likely using test plasma
| that isn't going to fuse.
| lazide wrote:
| You can buy an inexpensive plasma cutter at harbor freight
| that is happy to generate as much plasma as you want (while
| cutting metal). It definitely isn't doing any atomic fusion
| anywhere.
|
| It's also what arc welders weld with.
|
| Plasma is ionized gas (hence conductive), the 'fourth state
| of matter' and while usually hot, it doesn't necessary have
| to be.
|
| [https://en.m.wikipedia.org/wiki/Plasma_(physics)]
| CodeWriter23 wrote:
| Presented in the context of "in these gizmos". I did not
| say all plasma is fusion.
| lazide wrote:
| Most of these will be using plasma which is not fusing
| most of the time for testing, validation, etc.
|
| Fusing plasma makes a lot of neutrons which cause
| problems, including irradiating things.
| pantalaimon wrote:
| You can create a plasma in your microwave, that doesn't mean
| there is fusion.
| anonyfox wrote:
| AFAIK this is the proof that engineering has figured it out to
| have real stellarator fusion energy become a reality. Stuff
| works. It can keep plasma going for minutes as you wish. Now its
| the task of scaling I guess?
|
| I have hope that fusion energy is indeed only a few years away
| now, not always some decades. It would be just in time so to
| speak. Can we throw like 1/10 of the US military budget against
| this tech and have it solved?
| shaqbert wrote:
| This was a plasma physics experiment to prove continous
| operation. Apparently going from 8 min to much larger timespans
| is less of a leap now.
|
| Next stop in research: divertor design. Right now the divertor
| is still a challenge, as it heats up too much when the plasma
| gets hotter. You can see it in the video, the area that gets
| really bright in IR.
|
| After the divertor is figured out, the blanket comes next.
| Neutron embrittlement of the structure is another issue. So
| power generation is still way out there.
|
| Still, a great day for plasma physicists over the world.
| Decades of hard work went into this. Congrats!
| WJW wrote:
| Keeping plasma going and actually having fusion are two
| different things. This is an important step to be sure but the
| Wendelstein is very much an experimental reactor. It's not
| meant to be something that will ever make large amounts of
| electricity.
|
| Also note that the Wendelstein 7-X project started planning in
| 1980 and assembly took from 2005 until 2014. A US reactor
| experiment (the NCSX) was cancelled in 2009 because they
| couldn't get the required mechanical precision even in a lab
| setting. Even if we manage to solve the remaining technical
| challenges to sustained fusion in only five years (ie WAY ahead
| of the experimental schedule), building a power plant sized
| version would definitely take a decade or two including all the
| planning and actual construction.
|
| More budget will probably help speed up the timeline somewhat
| but probably not that much. If you truly had 1/10th of the
| military budget to spend you could probably get a much bigger
| bang for your buck if you spend it on solar panels, batteries
| and on shoring up coastal defences/stormwater systems/building
| insulation/etc etc etc. The boring stuff, rather than the
| "silver bullet" projects like fusion power plants.
| sva_ wrote:
| I also posted this earlier with English article instead of the
| German video description
|
| https://news.ycombinator.com/item?id=34924872
| kzrdude wrote:
| The video in the posting has both German and English video
| description
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