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Physicists Plan to Build a Bigger LHC
ananyo writes "When Europe's Large Hadron Collider (LHC) started up in 2008, particle physicists would not have dreamt of asking for something bigger until they got their US$5-billion machine to work. But with the 2012 discovery of the Higgs boson, the LHC has fulfilled its original promise — and physicists are beginning to get excited about designing a machine that might one day succeed it: the Very Large Hadron Collider. The giant machine would dwarf all of its predecessors (see 'Lord of the rings'). It would collide protons at energies around 100 TeV, compared with the planned 14TeV of the LHC at CERN, Europe's particle-physics lab near Geneva in Switzerland. And it would require a tunnel 80-100 kilometres around, compared with the LHC's 27-km circumference. For the past decade or so, there has been little research money available worldwide to develop the concept. But this summer, at the Snowmass meeting in Minneapolis, Minnesota — where hundreds of particle physicists assembled to dream up machines for their field's long-term future — the VLHC concept stood out as a favorite."
the BFHC?
hmmm....I wonder where they could build it. Oh - I know. Dallas. The tunnel has been dug so all they have to do is drop in a few magnates.
http://en.wikipedia.org/wiki/Superconducting_Super_Collider
On a more serious note, I though the next big project was going to be a linear accelerator. Anybody know why they picked the round one over the straight one?
A cost of $10 billion is peanuts compared to the $3.2-4 trillion cost of the Iraq war or the $12.8 trillion cost of the bank bailout.. Even if these figures are not very accurate, VLHC is, comparatively, not expensive.
The trouble is that VLHC does not enrich the friends of the politicans and so will not be looked on favourably. When will mankind grow up?
Make no mistake, I don't mean my subject as anti-science - From my point of view, I'd gladly give one of these to every university in the world before I'd pay for one more bullet fired from one more drone to kill one more Arab in a desert far away.
But in planning for a future desired collision energy, they really should have some actual goal in mind to justify that design. Do they hope to find dark matter? Black holes? Do they actually think they can make the Higgs break down into something else at that energy? So... Why?
You pesky physicists just keep running around in circles asking for more, MORE MORE money.. Is all this really necessary or are we really just funding a pile of PHD student's research?
So, why don't we just cut to the chase here and go with the biggest possible? I'm starting to get tired of this "We need a bigger one now!" thing.
Seriously, So now that they've managed to find the Higgs boson we are done with the LHC? I'm looking for a really good reason we need a bigger collider here and I'm not seeing any given. Is there some theory we need to test or some additional advances in technology which depend on a better understanding of subatomic physics at such large energies? I'm no physicist, but I'm not seeing a reason for this expense, other than having a new, bigger and more expensive shiny toy.
Help us out, what will 100 TeV get you that your 14 TeV won't?
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
The tunnel, while expensive, is probably a small portion of the overall cost. The bulk of the cost will be in the magnets, experiments, and computing. Locating a VLHC at the SSC tunnel in Texas probably wouldn't save a lot of money, especially when one factors in the other costs of putting it there.
meanwhile, in the great state of Texas, we have a very large hole with nothing to show for the effort. YAY JESUSLAND!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
They should kickstarter the money for it. I'll throw in $50. Flex goals: Stargate; flux capacitor; warp drive.
We don't have a state-run media we have a media-run state.
At what percentage of C would a 100TeV proton be traveling?
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Well, many of these tunnels, including the one the LHC uses, have been refurbished multiple times already. Cern's main ring was built to be somewhat future-proof, but that was a long time ago. A google search came up with The history of CERN, which dates the groundbreaking to 1954.
In accelerators you have two basic designs: linear and circular(ish). In linear accelerators each boosting element (RF cavity or whatnot) gets one chance to give the beam particles a kick, so the energy is limited to how hard you kick (limited by technology) and how many elements / how long (limited by budget).
In circular accelerators you are limited by synchrotron radiation. At some point the energy pumped into the beam matches the energy lost via synchrotron radiation. To move in a circle you have to accelerate inwardly, and an accelerating charged particle radiates light. At particle accelerator energies, this radiation is in the x-ray spectrum. You can reduce the loss by using a larger ring -- a smaller curvature requires less centripetal acceleration and hence less radiation loss. You can also of course build stronger boosting elements, but the radiation also heats the beamline and surrounding superconducting magnets, so it's not "that simple."
The other thing to vary is the kind of particle accelerated. Electrons have a very small mass and lose a larger fraction of their momentum to synchrotron radiation. SLAC and KEK are linear accelerators that use electrons. (Cornell's CESR is a ring that accelerates electrons too, but at lower energies compared to these others.) Protons are the other obvious choice, which is what Fermilab and CERN's LHC (after the upgrade) are accelerating. Being much more massive, the protons slough off less of their momentum to synchrotron radiation and can be accelerated to higher energies given the same size ring. The disadvantage of protons is that the energy of the proton is shared among its three quarks (and gluons I think) whereas the electron is truly singular as far as can be told.
I've been out of touch lately but as of at least 8 years ago three proposals were being discussed: VLHC -- big ring accelerating protons. Next Linear Collider (NLC) -- long linear accelerator for electrons. Muon collider -- a smaller ring (actually with straight sections like a track&field track) that produces and accelerates muons. Muons are just like electrons only 200 times more massive and is unstable with a half-life of 2 microseconds. The muon collider was thought to be an ideal Higgs factory, but with a lot of design challenges. One of the main challenges is to not only accelerate the muons before they decay, but also collimate, or "cool", the beam very fast as well so that you can create as many head-on collisions as possible.
So the news that the VLHC design is currently in favor is interesting, but this is hardly the first time the issue has been discussed and I doubt it will be the last. Several years ago the NLC design seemed most favorable, but this would, by its length, be limited to a specific design energy and probably be built to produce Higgs, Higgs, and more Higgs. It seems to me like a VLHC would have more discovery potential for more massive Higgs particles, signs of supersymmetry, or whatever else might exist.
I also wanted to mention the failed SSC in Texas, cancelled in 1993. That would have been running at double the LHC's energy about a decade earlier. In 1993 congress seats were won by senators promising budget cuts, and Big Science had a large target painted on its back. Killing the SSC was a big-profile way of appearing to reduce spending while at the same time not damaging something that many people understood or cared about.
Since that time, the US has proved time and time again that they are incapable of sustaining funding for a long-term science project. All of the high-energy accelerators in the US are operationally shut down, and almost no proposals in the past 20 years or so have survived all the way to producing results before getting scrapped by some budget shortfall in a particular fiscal year. The LHC survives because the US is not such a major (or critical) contributor.
The helium at LHC is liquid helium used to cool the superconducting magnets, not to fill the tunnel.
But maybe by the time this is built we'll have room-temperature (or nearly so) superconductors that can sustain that kind of magnetic field. (AFAIK the LN2-cooled ceramic superconductors can't.)
They need to get a naming convention started.
If the present one is the Large Hadron Collider, the next one the Very Large Hadron Collider, then the following one should be the Ultra Large Hadron Collider.
1. Large Hadron Collider
2. Very Large Hadron Collider
3. Ultra Large Hadron Collider
4. Extremely Large Hadron Collider
5. Gargantuan Large Hadron Collider
6. Mammoth Large Hadron Collider
7. Unbelievably Large Hadron Collider
8. Inconceivably Large Hadron Collider
9. Budget Busting Large Hadron Collider
After this, there won't be money left to build any more.
Each new larger collider should be constructed with it's center at the same center point as previous colliders. Thus all of the colliders form a set of concentric rings. They can be called the Nine Circles of Collision.
I'll see your senator, and I'll raise you two judges.
You hit numerical problems if you calculate it that way. Wikipedia gives a series expansion that works well for large values of gamma:
v (in units of c) = 1 - 1/2 \gamma^(-2)
v = c (1 - 1.8e-10), or 0.99999999982 c
Plaid
I swear to God...I swear to God! That is NOT how you treat your human!
It difficult to predict the benefits of machines that were not built. From past machines, work on linear electron colliders like the SLAC SLC and the never built but lots of R&D TESLA, and NLC led to high brightness electron linacs. Those are now being used to drive X-ray free electron lasers (DESY:FLASH, SLAC:LCLS, Spring-8 SCCS, Trieste , etc).
Those X-ray lasers are now being used extensively for practical research: protein structure measurement, femtosecond chemistry, superconductivity research, magnetic materials research, etc. Much of this has practical application in a 10 year timescale. The existing machines have so many users lined up ( we need to turn down 3/4 or our proposals at LCLS), that a bunch of new machines are being built or proposed around the world. (these are ~1B$ machines).
Then of course there are the spinoffs in low latency networks and distributed ffeedback, precision machining, etc.
Whether the basic physics will have practical applications is always difficult to tell. In the past, overall basic science has been a great investment, but it is difficult to tell if any particular investment will pay off.
But of course there is always a demand for bigger science.
They have to smuggle them in by labelling them as "jeebus detectors", "rapture attractors" and "age counter that only goes up to 6000".
Confucius say, "Find worm in apple - bad. Find half a worm - worse."