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Huge New Particle Collider at CERN: First Details & More False Claims
🕑 Added 2024-02-10 16:00:05 +0000 UTC[This is a transcript.]
We have seen a few new headlines this week about the plans of particle physicists to build a huge new collider at CERN in Geneva. I’ve had a look.
Particle physicists have called their new dream machine the “future circular collider”, FCC for short. The FCC is supposed to be a ring collider like the Large Hadron Collider, which is currently the biggest collider in the world. The LHC primarily collides protons, has a circumference of about 27 kilometres and reaches a collision energy of up to 14 Terra electron Volt.
When we first heard of CERN’s plans about 5 years ago, the circumference of the new collider was projected at 100 kilometres with a target energy of 100 Tera electron Volt. CERN then began commissioning more detailed plans and reports and the circumference has now been updated to merely 91 kilometres. It has also emerged that the tunnel will be deeper underground, on average 200 meters rather than about 80 meters like the LHC, probably due to geological features, and that the tunnel cross-section will be approximately 5 and a half meters.
CERN’s plan is to run the FCC project in two stages. The first stage is called the FCC-ee and would collide electrons. This stage would not reach any record energies, but “just” about roughly 400 GeV. This is actually lower than the energy that the LHC currently reaches. However, the LHC collides protons which are composite particles, made of three quarks. Electrons on the other hand are fundamental and not made up of anything.
That the LHC collides composite particles introduces some additional uncertainty and spreads out the energy in each collision over the constituents. An electron collider like the FCC-ee therefore can deliver better data even at lower energy.
The primary goals of this first stage would be to produce a lot of Higgs-bosons. The Higgs-boson was the last fundamental particle to be discovered, at the LHC in 2012. It’s still the new kid in town and hasn’t been studied as much as the other particles, so naturally particle physicists want to have a closer look.
If CERN can get the money together, which to my best knowledge has not yet happened, then constructions for the FCC-ee could begin within 5 years and it could start operating in the mid 2040s. The second stage would then be the FCC-hh, where h stands for “hadron”. It would then collide both protons and heavy ions like the LHC.
The projected construction cost for both stages is around 20 billion Euro or so. That does not include the operation costs which is probably something around a billion a year. The BBC article quotes a cost of 12 billion presumably for the first stage of the project. CERN will probably need some contributions from international partners to pull that off.
Why spend that amount of money? According to the BBC, the purpose of the bigger collider is to figure out what dark energy and dark matter is made of, as you can see in the title. The BBC didn’t invent that themselves, they got it from no other than CERN’s director general, Fabiola Gianotti. She is quoted saying that “the FCC is needed because the discovery of these dark particles would lead to a new more complete theory of how the Universe works.”
It's true that a discovery of dark particles, if they exist, would lead to a more complete theory of how the universe works, but there’s no reason to think that the FCC will be of any help in that. I find it honestly painful that CERN physicists still try to mislead the public about the prospects of their experiments. Let me remind you that they also told you that the LHC would find dark matter. Which it did not, and indeed it was never likely that it would. Now the first time they did this I was willing to believe that they were themselves confused. But now I am no longer willing to accept this excuse. At this point it’s deliberate misinformation.
Now look, it’s not that I am against particle physics or something. Some of my best friends are Higgs-bosons. I understand just fine that particle physicists want to measure a few more constants a little bit more precisely. But that’s not a good selling point is it.
The smarter of the particle physicists have recently tried to convince people that it’s somehow interesting to study the self-coupling of the Higgs field, but that didn’t quite catch on. Maybe not so surprisingly because besides particle physicists no one gives a damn about it.
Interestingly enough, American particle physicists seem to have noticed that the tide is turning, and they’re instead rallying for a muon collider. I talked about this in an earlier episode. That would almost certainly be less expensive and is also easier to sell because we’ve never had a muon collider before. Even if the thing doesn’t find anything, it has this novelty sticker going for it.
But I think particle physicists need to wake up. They seem to believe they’re entitled to dozens of billions of dollars in return for nothing in particular, while the world is going to hell in a handbasket. For what I am concerned, this future collider should remain a future collider.
Comments
Yes, in fact, I've been thinking about this recently. You see, CERN is betting a lot on this FCC thing and the trouble is, if that doesn't work, it'll be bad news for everything else they are doing, too. That'd be a shame.
Joshua Moody
I worked on AWAKE at CERN. We accelerated electrons out of a photoinjector from 16 MeV using an S-band linac up to 2 GeV over about 10 meters of rubidium vapor plasma ionized with a 4TW peak power laser. I was the laser guy. Don't believe me? Go find the papers. We used a single bunch out of SPS to drive the plasma wakefields. So 450 GeV/c^2 proton bunch of a few nC. Who cares about the FCC? I sure as hell don't. Let's make a 1 MJ CPA system using a plasma compressor like what was modelled by Hur et. al. https://www.nature.com/articles/s41566-023-01321-x I am going to use external fields to levitate liquid Rb and get the right density distribution to make a plasma compressor and curved mirror so I have a final focus optic and a compressor. If there is anyone with more experience and knowledge than me on this, let's have a gentle-human's bet on this who can make one faster. My nonprofit is already started and so has Ulsan. May the best gentle-human win the race. Then let's make a zetaWatt laser and get a TeV per meter plasma gradient. Peace, for all time, always. Good luck to us all (especially those who are screwed over by the global Bayesian probability tree like me). -Your friendly neighborhood physicist.
It seems that the physicists claiming the need for a bigger, more energetic collider would have some experimental evidence for it. What is their evidence excluding that we haven't found what they initially claimed for the LHC? It seems to me that the first order of business is to ensure that the current ideas, not theories yet, are accurate, right?
