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Quench of LHC inner triplet magnet causes a small leak with major consequences

239 points by untilted 3y ago

CrampusDestrus 3y ago
you mean "consequenches"
sakex 3y ago
Do we know if this could have an impact on the local population? Also is there any research on the effect of the LHC on people living in Geneva and around?
- jjgreen 3y ago
  I think they'll be OK: https://www.hasthelargehadroncolliderdestroyedtheworldyet.com/ https://www.hasthelargehadroncolliderdestroyedtheworldyet.co...
- fabian2k 3y ago
  > During such a quench, the liquid helium in the magnet warms up and turns into a gas that is recovered by the cryogenic system to be re-liquified, ready to cool down the magnets again. They're capturing the helium, so it isn't released usually. Not sure what they do with the nitrogen, I'd guess that is released as it is much cheaper. But in any case the amounts involved in such a quench are only a danger in the immediate vicinity, not outside. So if you're in the same room as a quenching magnet and the room isn't sufficiently sized or ventilated, there could be danger. But that's about the limit to it.
  - Ekaros 3y ago
    Took a tour in local university physics lab dealing with helium. My takeaway is that liquid nitrogen is essentially free. And used to protect or keep helium parts colder. So anyway in process you have so much of it that simply having it boil away or be discarded is not big deal.
    - gus_massa 3y ago
      A few years ago, while doing a physics lab for students in the university, we needed ice and liquid nitrogen. It was weird that is was easier to get some liquid nitrogen[1] than ice cubes[2]. IIRC we asked for the official price of liquid nitrogen, and it was similar to the price of soft drink like coke. [1] Because it was used regularly in a few of the research labs. Just get a dewar flask that is not made of glass, and ask nicely. [2] No refrigerator in the lab, the cafeteria didn't have any, most refrigerators had no ice cubes or a huge ice block where there use to be the ice cubes shelf.
    - SoftTalker 3y ago
      It's comparatively free; the air is nearly 80% nitrogen. The equipment to produce liquid nitrogen has a cost and uses a fair amount of electricity. Labs that use a lot of liquid nitrogen may produce their own, but often it's produced industrially in large quantities and trucked to customer sites. It has a lot of uses, from dermatology to machine shops.
- meindnoch 3y ago
  Severe mutations and deformities.
  - DoctorOetker 3y ago
    Brain damage for the schedule programmer.
- SiempreViernes 3y ago
  Uh, I guess some of the locals will get second-hand bummed-outedness from their acquaintances at CERN? Did you even click on the link dude? The picture showing frost on the outside of a metal tube in a sealed tunnel ~100 m under ground is the total extent of the exterior effects...
- harperlee 3y ago
  It is a small leak of helium that disables a refrigeration unit.
- cominous 3y ago
  Read the article. It was a >local< event at one of the magnets which caused the whole magnet to freeze over. The "consequences" are, that the whole accelerator needs to halt operations to repair the element. That takes quite a while and will postpone the schedule..
  - sakex 3y ago
    Sure but is it impossible that something would leak when injecting massive amounts of energy in a gigantic tunnel?
    - constantcrying 3y ago
      But what would leak? The helium? The nitrogen? The only real danger is if you are in an enclosed space and oxygen is displaced. Nitrogen gas is about the least toxic substance imaginable and helium will literally just go away unless you make absolutely sure to trap it.
      - __alexs 3y ago
        > Nitrogen gas is about the least toxic substance imaginable Interestingly basically all gasses appear to be bad for you in some way. Perhaps the vacuum of space truly is where we belong? /s https://en.wikipedia.org/wiki/Nitrogen_narcosis https://en.wikipedia.org/wiki/Nitrogen_narcosis I can't find the study right now but I think this affect is even measurable at atmospheric pressure in that if you give replace the Nitrogen with other noble gasses you can observe improvements in cognitive function.
        constantcrying 3y ago
        100% of substances are bad for you under some circumstances. You have breathed in millions of liters of nitrogen. It is as safe as any substance could possibly be.
    - flangola7 3y ago
      Besides helium, what substances are you worried about leaking?
- imdsm 3y ago
  Do we know if... the magnet heating up, and the helium leaking into the vacuum chamber... could have an impact on the local population? I think they'll be ok!
  - contravariant 3y ago
    I mean worst that could happen is that it's harmful to someone standing right next to it if it fails catastrophically (no clue if that's even a realistic concern in this case). But since this happens over 50 meters below ground I'm not too worried. Not that it was put that far below ground for safety reasons, it was mostly to save on the amount of land required and to shield the detectors from pesky background radiation (not the other way around).
    - cesarb 3y ago
      > I mean worst that could happen is that it's harmful to someone standing right next to it if it fails catastrophically (no clue if that's even a realistic concern in this case). AFAIK, these areas are restricted while the LHC is operating, so there would be nobody near it (and I believe trying to enter these areas triggers an interlock which stops the whole system before you can get near it).
      - salawat 3y ago
        If the beam shaping catastrophically fails due to the magnet failing completely, as I understand it, you can get a beam excursion from the beam track that results in a hell of a lot of irradiated earth as the beam does what beams do to everything in its way. IIRC from my short time intersecting with the finer points of collider discussion, they locate them in such areas where generally if such things happen, it's a non-issue; but take great pains to ensure that such events don't happen, as it would require potential excavation and removal of a lot of hardware to replace the irradiated sections to restore a contamination free loop. It's also, if I recall correctly, part of why circular paths were chosen instead of things like ovals or capsules for the path shape among other factors I think like optimization for cheapest construction. Any loss of beam containment would continue on a tangent ensuring one and only one segment of the collider would potentially have to be replaced; other shapes would end up with magnets that were relatively more catastrophic to have fail due to the excursion geometry having more opportunities to escape along a path near parallel to the track, allowing the irradiation of additional accelerator segments. Which would be a hell of a lot more expensive to remediate. I sometimes laugh, because in the business world, people like to talk about what is 'reasonably forseeable'. I'm a bit of a stick in the mud at such times because I can generally say that exactly no one in the room is actually interested in ptobing the actual boundaries of the reasonably forseeable, as that would require doing too much math. I'm regularly right in that regard.
- gostsamo 3y ago
  Noble gases are not chemically active, but some interdementional rifts might allow access of alternative life forms to our reality.
  - rob74 3y ago
    I think you're mixing things up - the incident you are referring to happened at the Black Mesa Research Facility, not at the LHC...
    - gostsamo 3y ago
      The LHC was a cover. Do you really think that governments honestly will spend billions for fundamental science without a back motive? It is the ideal environment to hide a secret base where they can divert money, energy, and people to.
- Aardwolf 3y ago
  Unbelievable the LHC is already running for 15 years! When it was just finished it was still the heyday of funny flash animations on the internet, some of course joking about the LHC ending the world: https://www.newgrounds.com/portal/view/469806 https://www.newgrounds.com/portal/view/469806
  - sakex 3y ago
    Yes I think it's great, but still it would be good to have research to understand the effect on local population. It is intellectually dishonest to just say it is not possible for anything to leak and have adverse effects on people without actively researching the matter.
    - contravariant 3y ago
      You should really do some more extensive research about the possible harmful effects of your comments more carefully before posting. This one is giving me a headache.
    - bradrn 3y ago
      The was a small leak of helium within the instrument. Such incidents are completely unexceptional with superconducting magnets, and pose no risk to anyone outside the room where it happen, since both helium and nitrogen are about as inert as gases can get. I suspect it wouldn’t even have made the news if it hadn’t delayed the experiments.
    - fabian2k 3y ago
      We know what helium and nitrogen gas do and what dangers they represent. We also know how much of them are in the LHC. The main danger is that both displace oxygen, so you can suffocate e.g. if a large amount of helium is released by a quench in a small room. But this isn't any danger to the surrounding area, there just isn't enough liquid helium or nitrogen in there. Both gases are inert, so they really don't do anything else. There isn't anything to investigate here.
    - db48x 3y ago
      It’s just helium. Have you ever bought a helium balloon, the kind that float? This is the same stuff that’s in the balloon. It’s also used as a mixture gas by deep–sea divers. It's chemically completely inert; breathing it in doesn’t have any particular effect on the body. It’s harmless, unless you fill an entire room with it so that all the oxygen is displaced. Are people really so scientifically illiterate that they immediately assume that if anything goes wrong with a complicated machine that it will be harmful to their health?
- pif 3y ago
  What do you propose exactly? What should we monitor? By the way, I worked at CERN for a few years up to the first months of operations of LHC. Furthermore, I've been living in the region since then; for several years, my home was exactly over the LHC tunnel. I've never got a nightmare from that!
- SoftTalker 3y ago
  Not sure, but the engineers all came running out of the room talking like Mickey Mouse.
aredox 3y ago
I was there when there was a (much bigger) quench during commissioning of the LHC [0][1]. It was also at the focusing quadrupole modules - maybe the same ones? I could make a joke about how it's Fermilab's vengeance for not having their own accelerator, but that would be dishonest: these focusing modules are the most complex ones of the whole ring. [0]http://stephatcern.blogspot.com/2008/12/photos-of-lhc-damage.html?m=1 http://stephatcern.blogspot.com/2008/12/photos-of-lhc-damage... [1]https://home.cern/news/press-release/cern/cern-releases-analysis-lhc-incident https://home.cern/news/press-release/cern/cern-releases-anal...
- notanote 3y ago
  The 2008 quench happened at the other side of the ring. (Sector 3-4 then, sector 7-8 now.) The physics run was going very smoothly up to now [0]. Last year part of the machine (RF) had to be brought to room temperature as well, after a cooling tower fault, and there was no beam for four weeks. I get the impression that this will take longer, but I hope not by much. [0]https://atlas.web.cern.ch/Atlas/GROUPS/DATAPREPARATION/PublicPlots/2023/DataSummary/figs/intlumivsyear.png https://atlas.web.cern.ch/Atlas/GROUPS/DATAPREPARATION/Publi...
SiempreViernes 3y ago
Man, so relieved it's just cooling one section that is meant by "major consequences", title made me think of the explosion during commissioning. Looks like it's only sector S78 that needs attention: https://op-webtools.web.cern.ch/vistar/vistars.php?usr=LHC2 https://op-webtools.web.cern.ch/vistar/vistars.php?usr=LHC2 This report is impressively detailed for being put out just two days of the incident, but I guess LHC having world class technical diagnostics teams is not too surprising.
- bayindirh 3y ago
  When I was visiting CERN, the whole accelerator was in maintenance mode. We have seen a detector (IIRC it was ATLAS) which was disassembled in layers, so we were able to see almost all of it. Our guide explained that whole schedule for maintenance and operation is set in stone and whole schedule is planned almost to hour resolution for the next six months or so. Also it's worth noting that, there is periodic maintenance that needs to be done, and that's also planned in advance. Because of this stringent requirements, "several weeks" of shift is indeed a major problem, and by several I guess they are looking to ~8 weeks, if not more.
  - FireBeyond 3y ago
    My uncle, who is not a physicist, but "one smart mf", was one of the heads of the beam instrumentation team at Fermilab, and spent a large part of his career designing, building and maintaining detectors. It utterly blows my mind.
- vasco 3y ago
  The "major consequences" seem to be for the schedule: > This incident will probably have a great impact on the LHC schedule, with machine operation unlikely to resume for at least several weeks. I also read it instantly in case they had a black hole on their hands, even though I'd expect us all to be dead almost instantly if any real "major consequence" event truly happened in the accelerators.
  - 3cats-in-a-coat 3y ago
ggm 3y ago
The inner tube is hard vacuum? Does freeze over risk rupture and also incur re evacuation and time to get those last pesky digits of nothing?
fifteen1506 3y ago
For major click-bait for Half-Life 1 players, I propose the title to be prefixed with "UNFORESEEN CONSEQUENCES: ".
- Gordonjcp 3y ago
  I never thought I'd see a resonance cascade...
- misterflibble 3y ago
  Gordon! Get away from the beam!!!!
- ComodoHacker 3y ago
  This report really has disturbingly strong Half-Life 1 vibes for me.
  - FeepingCreature 3y ago
    "It's not... it's not shutting down! Aah-- oh wait, it shut down. All good."
  - Aardwolf 3y ago
    The major consequence here is a few weeks of repair time, there wouldn't be much gameplay in Half-Life 1 if that were it :)
fancyfredbot 3y ago
It is amazing that the beam was "dumped" just milliseconds before the magnet quenched! If that hadn't happened then the beam could have crashed into the magnet and caused a lot more damage. Dumping the beam means diverting it out of the main LHC ring and crashing it into a specially designed buffer (I think it is a lump of steel or something). So cool to see this all happening automatically.
- zelos 3y ago
  It hadn't occurred to me that there would be significant energy contained in a beam of sub-atomic particles. Something like 100kg TNT equivalent (~500MJ)? Wow.
  - testtestabcdef 3y ago
    That's crazy. I never would've thought that either. These small facts which you can barely read in "mainstream media" are what makes the LHC absolutely fascinating and impressive. I was always like "Yeah that's just a small beam and the magnets are to navigate it in circles". In retrospect it does make sense now why people were concerned about the collision of such beams.
    - Ekaros 3y ago
      Also, when you really think about it. Why would you need 27 kilometre long circle if you weren't dealing with some absolutely massive amounts of energy. Couldn't you do it with lot less?
      - Sharlin 3y ago
        Indeed. It’s all about the curvature. Even with all those incredibly fancy superconducting magnets you just can’t force protons this fast onto a circular path any smaller than this when they very much would like to go straight.
  - rcxdude 3y ago
    Yeah, it has the energy of a semi truck going at a few hundred mph but in something that is about 1nanogram of mass (about that of the average human cell).
zipotm 3y ago
[flagged]
unixhero 3y ago
Unforeseen consequences Don't forget your crowbar
ur-whale 3y ago
"Major consequences", and here I was already think a beam of protons flying at near the speed of light was let loose towards the city of Geneva. But no, just a section of the accelerator that needs fixing.
testing_123 3y ago
[flagged]
codeulike 3y ago
Quench Nice verb
ThePhysicist 3y ago
Helium leaks are a nightmare. During my PhD I worked with a self-built dilution cryostat that would often have leaks in the custom-built Indium seals. To find the leaks you'd have to pump the cryostat to high vacuum, hook up a portable mass spectrometer tuned to Helium to the pump circuit and then spray different parts of the cryostat with Helium from a regular gas canister. The He would then get sucked in through the leak and show up on the mass spectrometer, which was coupled to a loudspeaker so it would cause a sound whose pitch increased with the measured He density. Once you found the leak you had to vent the entire system, remove the faulty seal and replace it with a new one. All seals were handmade, i.e. you took a small filament of Indium, placed it between the flange and the housing (after carefully cleaning everything with Acetone) and carefully screwed it shut, turning each screw only a tiny bit at each turn and going around all the screws until you could see the Indium squeeze out of the edges. Even worse, some leaks would only show up when the system got cooled down to liquid Helium temperature. When that happened you were out of luck as you can't cool the system down to 4K before spraying it with Helium, so you had to just guess where the leak might be and replace all seals in that area until you found the right one. Going even deeper in temperature would eventually turn the He4 suprafluid, which means that it loses all internal friction. In that state it would squeeze through even the tiniest molecular cracks, so again if that happened you just had to redo all the seals and hope they would hold.
- user3939382 3y ago
  This is a more extreme description of why I hate plumbing.
  - nazgulsenpai 3y ago
    As someone who is currently in a game of cat and mouse with an intermittent drip from underneath the kitchen sink, this was exactly the first thing that came to my mind also!
    - lotsofpulp 3y ago
      I feel like I would just replace all of it than play cat and mouse. Surely it would be cheaper in time, and low cost until you figure out you have to replace the whole sink.
formerly_proven 3y ago
This is a very nicely written, clear article. This is what good science communication looks like.
dr_faustus 3y ago
Just reading that gives you an inkling of an idea what kind of amazing feat of engineering the LHC is. I really hope governments keep funding basic research like that because it teaches us not only about nature but also how to built those incredible machines.
noobermin 3y ago
Bad time to be an LHC grad student.
enslavedrobot 3y ago
Quenching a magnet is the result of poor planning and poor maintenance. The only time I ever hear about magnets quenching is at CERN. I remember they quenched ~40 at once when they first turned it on, a multi-million dollar error. What the hell are they up to over there!?
trenchgun 3y ago
Tiny black holes that are going to swallow the earth in the coming hours?
lhoff 3y ago
Partially related recommendation for the german-speaking crowd here: The Raumzeit podcast released the second episode of a longer series about the cern. In the frist one he discussed the history and success of the cern with the leader of the experimental physics department and in the second one he talks to the guy who is in charge of operations of the proton synchrotron about the actual accelerators. https://raumzeit-podcast.de/2023/07/05/rz111-cern-geschichte-und-erfolge/ https://raumzeit-podcast.de/2023/07/05/rz111-cern-geschichte... https://raumzeit-podcast.de/2023/07/19/rz112-cern-die-beschleuniger-kette/ https://raumzeit-podcast.de/2023/07/19/rz112-cern-die-beschl...
Animats 3y ago
Not too bad. The 2008 magnet failure took two years to repair, with over 50 magnets affected.

239 points by untilted 3y ago

you mean "consequenches"

Do we know if this could have an impact on the local population? Also is there any research on the effect of the LHC on people living in Geneva and around?

jjgreen 3y ago
I think they'll be OK: https://www.hasthelargehadroncolliderdestroyedtheworldyet.com/ https://www.hasthelargehadroncolliderdestroyedtheworldyet.co...
fabian2k 3y ago
> During such a quench, the liquid helium in the magnet warms up and turns into a gas that is recovered by the cryogenic system to be re-liquified, ready to cool down the magnets again. They're capturing the helium, so it isn't released usually. Not sure what they do with the nitrogen, I'd guess that is released as it is much cheaper. But in any case the amounts involved in such a quench are only a danger in the immediate vicinity, not outside. So if you're in the same room as a quenching magnet and the room isn't sufficiently sized or ventilated, there could be danger. But that's about the limit to it.
- Ekaros 3y ago
  Took a tour in local university physics lab dealing with helium. My takeaway is that liquid nitrogen is essentially free. And used to protect or keep helium parts colder. So anyway in process you have so much of it that simply having it boil away or be discarded is not big deal.
  - gus_massa 3y ago
    A few years ago, while doing a physics lab for students in the university, we needed ice and liquid nitrogen. It was weird that is was easier to get some liquid nitrogen[1] than ice cubes[2]. IIRC we asked for the official price of liquid nitrogen, and it was similar to the price of soft drink like coke. [1] Because it was used regularly in a few of the research labs. Just get a dewar flask that is not made of glass, and ask nicely. [2] No refrigerator in the lab, the cafeteria didn't have any, most refrigerators had no ice cubes or a huge ice block where there use to be the ice cubes shelf.
  - SoftTalker 3y ago
    It's comparatively free; the air is nearly 80% nitrogen. The equipment to produce liquid nitrogen has a cost and uses a fair amount of electricity. Labs that use a lot of liquid nitrogen may produce their own, but often it's produced industrially in large quantities and trucked to customer sites. It has a lot of uses, from dermatology to machine shops.
meindnoch 3y ago
Severe mutations and deformities.
- DoctorOetker 3y ago
  Brain damage for the schedule programmer.
SiempreViernes 3y ago
Uh, I guess some of the locals will get second-hand bummed-outedness from their acquaintances at CERN? Did you even click on the link dude? The picture showing frost on the outside of a metal tube in a sealed tunnel ~100 m under ground is the total extent of the exterior effects...
harperlee 3y ago
It is a small leak of helium that disables a refrigeration unit.
cominous 3y ago
Read the article. It was a >local< event at one of the magnets which caused the whole magnet to freeze over. The "consequences" are, that the whole accelerator needs to halt operations to repair the element. That takes quite a while and will postpone the schedule..
- sakex 3y ago
  Sure but is it impossible that something would leak when injecting massive amounts of energy in a gigantic tunnel?
  - constantcrying 3y ago
    But what would leak? The helium? The nitrogen? The only real danger is if you are in an enclosed space and oxygen is displaced. Nitrogen gas is about the least toxic substance imaginable and helium will literally just go away unless you make absolutely sure to trap it.
    - __alexs 3y ago
      > Nitrogen gas is about the least toxic substance imaginable Interestingly basically all gasses appear to be bad for you in some way. Perhaps the vacuum of space truly is where we belong? /s https://en.wikipedia.org/wiki/Nitrogen_narcosis https://en.wikipedia.org/wiki/Nitrogen_narcosis I can't find the study right now but I think this affect is even measurable at atmospheric pressure in that if you give replace the Nitrogen with other noble gasses you can observe improvements in cognitive function.
      - constantcrying 3y ago
        100% of substances are bad for you under some circumstances. You have breathed in millions of liters of nitrogen. It is as safe as any substance could possibly be.
  - flangola7 3y ago
    Besides helium, what substances are you worried about leaking?
imdsm 3y ago
Do we know if... the magnet heating up, and the helium leaking into the vacuum chamber... could have an impact on the local population? I think they'll be ok!
- contravariant 3y ago
  I mean worst that could happen is that it's harmful to someone standing right next to it if it fails catastrophically (no clue if that's even a realistic concern in this case). But since this happens over 50 meters below ground I'm not too worried. Not that it was put that far below ground for safety reasons, it was mostly to save on the amount of land required and to shield the detectors from pesky background radiation (not the other way around).
  - cesarb 3y ago
    > I mean worst that could happen is that it's harmful to someone standing right next to it if it fails catastrophically (no clue if that's even a realistic concern in this case). AFAIK, these areas are restricted while the LHC is operating, so there would be nobody near it (and I believe trying to enter these areas triggers an interlock which stops the whole system before you can get near it).
    - salawat 3y ago
      If the beam shaping catastrophically fails due to the magnet failing completely, as I understand it, you can get a beam excursion from the beam track that results in a hell of a lot of irradiated earth as the beam does what beams do to everything in its way. IIRC from my short time intersecting with the finer points of collider discussion, they locate them in such areas where generally if such things happen, it's a non-issue; but take great pains to ensure that such events don't happen, as it would require potential excavation and removal of a lot of hardware to replace the irradiated sections to restore a contamination free loop. It's also, if I recall correctly, part of why circular paths were chosen instead of things like ovals or capsules for the path shape among other factors I think like optimization for cheapest construction. Any loss of beam containment would continue on a tangent ensuring one and only one segment of the collider would potentially have to be replaced; other shapes would end up with magnets that were relatively more catastrophic to have fail due to the excursion geometry having more opportunities to escape along a path near parallel to the track, allowing the irradiation of additional accelerator segments. Which would be a hell of a lot more expensive to remediate. I sometimes laugh, because in the business world, people like to talk about what is 'reasonably forseeable'. I'm a bit of a stick in the mud at such times because I can generally say that exactly no one in the room is actually interested in ptobing the actual boundaries of the reasonably forseeable, as that would require doing too much math. I'm regularly right in that regard.
gostsamo 3y ago
Noble gases are not chemically active, but some interdementional rifts might allow access of alternative life forms to our reality.
- rob74 3y ago
  I think you're mixing things up - the incident you are referring to happened at the Black Mesa Research Facility, not at the LHC...
  - gostsamo 3y ago
    The LHC was a cover. Do you really think that governments honestly will spend billions for fundamental science without a back motive? It is the ideal environment to hide a secret base where they can divert money, energy, and people to.
Aardwolf 3y ago
Unbelievable the LHC is already running for 15 years! When it was just finished it was still the heyday of funny flash animations on the internet, some of course joking about the LHC ending the world: https://www.newgrounds.com/portal/view/469806 https://www.newgrounds.com/portal/view/469806
- sakex 3y ago
  Yes I think it's great, but still it would be good to have research to understand the effect on local population. It is intellectually dishonest to just say it is not possible for anything to leak and have adverse effects on people without actively researching the matter.
  - contravariant 3y ago
    You should really do some more extensive research about the possible harmful effects of your comments more carefully before posting. This one is giving me a headache.
  - bradrn 3y ago
    The was a small leak of helium within the instrument. Such incidents are completely unexceptional with superconducting magnets, and pose no risk to anyone outside the room where it happen, since both helium and nitrogen are about as inert as gases can get. I suspect it wouldn’t even have made the news if it hadn’t delayed the experiments.
  - fabian2k 3y ago
    We know what helium and nitrogen gas do and what dangers they represent. We also know how much of them are in the LHC. The main danger is that both displace oxygen, so you can suffocate e.g. if a large amount of helium is released by a quench in a small room. But this isn't any danger to the surrounding area, there just isn't enough liquid helium or nitrogen in there. Both gases are inert, so they really don't do anything else. There isn't anything to investigate here.
  - db48x 3y ago
    It’s just helium. Have you ever bought a helium balloon, the kind that float? This is the same stuff that’s in the balloon. It’s also used as a mixture gas by deep–sea divers. It's chemically completely inert; breathing it in doesn’t have any particular effect on the body. It’s harmless, unless you fill an entire room with it so that all the oxygen is displaced. Are people really so scientifically illiterate that they immediately assume that if anything goes wrong with a complicated machine that it will be harmful to their health?
pif 3y ago
What do you propose exactly? What should we monitor? By the way, I worked at CERN for a few years up to the first months of operations of LHC. Furthermore, I've been living in the region since then; for several years, my home was exactly over the LHC tunnel. I've never got a nightmare from that!
SoftTalker 3y ago
Not sure, but the engineers all came running out of the room talking like Mickey Mouse.

aredox 3y ago

I was there when there was a (much bigger) quench during commissioning of the LHC [0][1]. It was also at the focusing quadrupole modules - maybe the same ones? I could make a joke about how it's Fermilab's vengeance for not having their own accelerator, but that would be dishonest: these focusing modules are the most complex ones of the whole ring. [0]http://stephatcern.blogspot.com/2008/12/photos-of-lhc-damage.html?m=1 http://stephatcern.blogspot.com/2008/12/photos-of-lhc-damage... [1]https://home.cern/news/press-release/cern/cern-releases-analysis-lhc-incident https://home.cern/news/press-release/cern/cern-releases-anal...

notanote 3y ago
The 2008 quench happened at the other side of the ring. (Sector 3-4 then, sector 7-8 now.) The physics run was going very smoothly up to now [0]. Last year part of the machine (RF) had to be brought to room temperature as well, after a cooling tower fault, and there was no beam for four weeks. I get the impression that this will take longer, but I hope not by much. [0]https://atlas.web.cern.ch/Atlas/GROUPS/DATAPREPARATION/PublicPlots/2023/DataSummary/figs/intlumivsyear.png https://atlas.web.cern.ch/Atlas/GROUPS/DATAPREPARATION/Publi...

SiempreViernes 3y ago

Man, so relieved it's just cooling one section that is meant by "major consequences", title made me think of the explosion during commissioning. Looks like it's only sector S78 that needs attention: https://op-webtools.web.cern.ch/vistar/vistars.php?usr=LHC2 https://op-webtools.web.cern.ch/vistar/vistars.php?usr=LHC2 This report is impressively detailed for being put out just two days of the incident, but I guess LHC having world class technical diagnostics teams is not too surprising.

bayindirh 3y ago
When I was visiting CERN, the whole accelerator was in maintenance mode. We have seen a detector (IIRC it was ATLAS) which was disassembled in layers, so we were able to see almost all of it. Our guide explained that whole schedule for maintenance and operation is set in stone and whole schedule is planned almost to hour resolution for the next six months or so. Also it's worth noting that, there is periodic maintenance that needs to be done, and that's also planned in advance. Because of this stringent requirements, "several weeks" of shift is indeed a major problem, and by several I guess they are looking to ~8 weeks, if not more.
- FireBeyond 3y ago
  My uncle, who is not a physicist, but "one smart mf", was one of the heads of the beam instrumentation team at Fermilab, and spent a large part of his career designing, building and maintaining detectors. It utterly blows my mind.
vasco 3y ago
The "major consequences" seem to be for the schedule: > This incident will probably have a great impact on the LHC schedule, with machine operation unlikely to resume for at least several weeks. I also read it instantly in case they had a black hole on their hands, even though I'd expect us all to be dead almost instantly if any real "major consequence" event truly happened in the accelerators.
- 3cats-in-a-coat 3y ago

ggm 3y ago

The inner tube is hard vacuum? Does freeze over risk rupture and also incur re evacuation and time to get those last pesky digits of nothing?

fifteen1506 3y ago

For major click-bait for Half-Life 1 players, I propose the title to be prefixed with "UNFORESEEN CONSEQUENCES: ".

Gordonjcp 3y ago
I never thought I'd see a resonance cascade...
misterflibble 3y ago
Gordon! Get away from the beam!!!!
ComodoHacker 3y ago
This report really has disturbingly strong Half-Life 1 vibes for me.
- FeepingCreature 3y ago
  "It's not... it's not shutting down! Aah-- oh wait, it shut down. All good."
- Aardwolf 3y ago
  The major consequence here is a few weeks of repair time, there wouldn't be much gameplay in Half-Life 1 if that were it :)

fancyfredbot 3y ago

It is amazing that the beam was "dumped" just milliseconds before the magnet quenched! If that hadn't happened then the beam could have crashed into the magnet and caused a lot more damage. Dumping the beam means diverting it out of the main LHC ring and crashing it into a specially designed buffer (I think it is a lump of steel or something). So cool to see this all happening automatically.

zelos 3y ago
It hadn't occurred to me that there would be significant energy contained in a beam of sub-atomic particles. Something like 100kg TNT equivalent (~500MJ)? Wow.
- testtestabcdef 3y ago
  That's crazy. I never would've thought that either. These small facts which you can barely read in "mainstream media" are what makes the LHC absolutely fascinating and impressive. I was always like "Yeah that's just a small beam and the magnets are to navigate it in circles". In retrospect it does make sense now why people were concerned about the collision of such beams.
  - Ekaros 3y ago
    Also, when you really think about it. Why would you need 27 kilometre long circle if you weren't dealing with some absolutely massive amounts of energy. Couldn't you do it with lot less?
    - Sharlin 3y ago
      Indeed. It’s all about the curvature. Even with all those incredibly fancy superconducting magnets you just can’t force protons this fast onto a circular path any smaller than this when they very much would like to go straight.
- rcxdude 3y ago
  Yeah, it has the energy of a semi truck going at a few hundred mph but in something that is about 1nanogram of mass (about that of the average human cell).

zipotm 3y ago

[flagged]

unixhero 3y ago

Unforeseen consequences Don't forget your crowbar

ur-whale 3y ago

"Major consequences", and here I was already think a beam of protons flying at near the speed of light was let loose towards the city of Geneva. But no, just a section of the accelerator that needs fixing.

testing_123 3y ago

[flagged]

codeulike 3y ago

Quench Nice verb

ThePhysicist 3y ago

Helium leaks are a nightmare. During my PhD I worked with a self-built dilution cryostat that would often have leaks in the custom-built Indium seals. To find the leaks you'd have to pump the cryostat to high vacuum, hook up a portable mass spectrometer tuned to Helium to the pump circuit and then spray different parts of the cryostat with Helium from a regular gas canister. The He would then get sucked in through the leak and show up on the mass spectrometer, which was coupled to a loudspeaker so it would cause a sound whose pitch increased with the measured He density. Once you found the leak you had to vent the entire system, remove the faulty seal and replace it with a new one. All seals were handmade, i.e. you took a small filament of Indium, placed it between the flange and the housing (after carefully cleaning everything with Acetone) and carefully screwed it shut, turning each screw only a tiny bit at each turn and going around all the screws until you could see the Indium squeeze out of the edges. Even worse, some leaks would only show up when the system got cooled down to liquid Helium temperature. When that happened you were out of luck as you can't cool the system down to 4K before spraying it with Helium, so you had to just guess where the leak might be and replace all seals in that area until you found the right one. Going even deeper in temperature would eventually turn the He4 suprafluid, which means that it loses all internal friction. In that state it would squeeze through even the tiniest molecular cracks, so again if that happened you just had to redo all the seals and hope they would hold.

user3939382 3y ago
This is a more extreme description of why I hate plumbing.
- nazgulsenpai 3y ago
  As someone who is currently in a game of cat and mouse with an intermittent drip from underneath the kitchen sink, this was exactly the first thing that came to my mind also!
  - lotsofpulp 3y ago
    I feel like I would just replace all of it than play cat and mouse. Surely it would be cheaper in time, and low cost until you figure out you have to replace the whole sink.

formerly_proven 3y ago

This is a very nicely written, clear article. This is what good science communication looks like.

dr_faustus 3y ago

Just reading that gives you an inkling of an idea what kind of amazing feat of engineering the LHC is. I really hope governments keep funding basic research like that because it teaches us not only about nature but also how to built those incredible machines.

noobermin 3y ago

Bad time to be an LHC grad student.

enslavedrobot 3y ago

Quenching a magnet is the result of poor planning and poor maintenance. The only time I ever hear about magnets quenching is at CERN. I remember they quenched ~40 at once when they first turned it on, a multi-million dollar error. What the hell are they up to over there!?

trenchgun 3y ago

Tiny black holes that are going to swallow the earth in the coming hours?

lhoff 3y ago

Partially related recommendation for the german-speaking crowd here: The Raumzeit podcast released the second episode of a longer series about the cern. In the frist one he discussed the history and success of the cern with the leader of the experimental physics department and in the second one he talks to the guy who is in charge of operations of the proton synchrotron about the actual accelerators. https://raumzeit-podcast.de/2023/07/05/rz111-cern-geschichte-und-erfolge/ https://raumzeit-podcast.de/2023/07/05/rz111-cern-geschichte... https://raumzeit-podcast.de/2023/07/19/rz112-cern-die-beschleuniger-kette/ https://raumzeit-podcast.de/2023/07/19/rz112-cern-die-beschl...

Animats 3y ago

Not too bad. The 2008 magnet failure took two years to repair, with over 50 magnets affected.