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."

Comments

Call it...

[cptnapalm]

the BFHC?

Re: Call it...

[O('_')O_Bush]

BADFFR

Big ass distractin from fusion research

I mean, the LHC was a neat project, but what practical benefits to humanity have come from it? Knowledge is great, but the Higg's discovery isn't solving the problems the world faces.

I know money and research into our energy needs could come from lots of places, but when I see massive facility of extreme high tech, employing thousands of physicists and researchers with international funding and support, and Billions of dollars budget, I can't help but think a similar problem with much greater utility is being neglected to all of our detriment.

Re: Call it...

[Anonymous Coward]

It's possible to do both. Besides, if your plan is "fusion at all costs", don't forget that the science involved (like computational techniques, materials science, etc...) are often cross-pollinated between the different fields.

ITER is being built in France as we speak. Construction on this hypothetical vlhc would start in the 2030s, if it happens at all.

Dallas?

[alexander_686]

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?

Re:Dallas?

[i kan reed]

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.

I'm all for putting Donald Trump underground, but shouldn't we cover the hole with dirt afterwards?

Re:Dallas?

[EvilSS]

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

Not sure how dropping a few billionaires into a hole in Texas would help get this project built but I'm not opposed to trying it.

Re:Dallas?

[SomeKDEUser]

This is true, but no so simple: in a straight line, you gain energy with the distance. When going round, you lose energy to stay in the loop as a function of the radius (the infinite radius case brings you back to the straight line). Thus, each time you want more energy, your collider ring needs to have considerably larger radius (following a third power law). At some point (basically the point after this proposal) you have to loop around the solar system :)

Re:Dallas?

[Anonymous Coward]

There's a tradeoff in circular/linear accelerators. Linear accelerators let you collide leptons (usually electrons) efficiently and leptons provide a MUCH cleaner signal. A comparable energy circular accelerator can be shorter, but due to bremsstrahlung losses, you have to collide hadrons (like protons), which provides a much messier signal.

After you do some rough calculations of what particles you can collide, their energies and the number of interactions per second, you then take those numbers and plug them into a model of a hypothetical detector along with a number of theories you'd like to explore to see which configuration gives you the biggest "bang for your buck"

The issue is that different people are more interested in probing different kinds of physics and it's impossible to make a detector/accelerator that's sensitive enough to fully probe everything, so big arguments happen at places like Snowmass. We know that we basically can only ask for one multi-billion dollar accelerator, so everyone's fighting to keep their pet research alive.

Re:Dallas?

[Attila the Bun]

There are also ideas to build a circular muon collider. Muons are similar to electrons so give a nice clean signal in the detectors, but being 200 times heavier than electrons they lose much less energy as they circulate around a ring-shaped path.

The problem is muons are unstable, with a half-life of just 2 micro-seconds. But if you can collect them fast enough and accelerate them to near-light-speed, their lifetime increases due to time dilation. The nearer they get to light-speed the longer they last for, and it's thought that it would be feasible to get them going fast enough that they would last for a useful amount of time.

There are lots of advantages to circular accelerators: You can re-use the expensive accelerating sections thousands of times over by recirculating the beam; the beam itself is re-used over and over (only a tiny fraction of the particle are lost on each collision); and most importantly you can install more than one detector. Having two independent measurements is very important in establishing the reliability of any results.

Re:Dallas?

[GodfatherofSoul]

No need to fill in the hole; just comb over it.

Re:Dallas?

[joe_frisch]

Muon colliders are a great concept - but they are difficult REALLY difficult. There is a significant ongoing effort to work on the technologies but they are far from ready now.

Personally I love the idea of high gradient RF cavities fabricated from Beryllium, filled with high pressure hydrogen, with megawatt high energy muon beams. There are however some possible....failure modes. Then there are the problems with neutrino radiation (I'm not kidding - it can exceed allowable dose limits).

A potentially more serious issue is that while the muon collisions themselves are very clean, the decaying muons create a huge amount of background noise in the detectors.

I think its a great project and work should continue - but like laser acceleration we can't build a machine like this yet.

Peanuts

[Alain Williams]

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?

Re:Peanuts

[EvilSS]

The trouble is that VLHC does not enrich the friends of the politicans and so will not be looked on favourably.

Oh, yea of little faith. I'm fairly certain anything that involves land acquisition and construction contracts will benefit SOME politician somewhere.

Re:Peanuts

[joe_frisch]

Sadly its not that simple. Imagine lab "A" says they have a design they can build for 10B and lab "B" says it will cost $11B - and assume both labs have similar good reputations for building large projects. "A" gets the project and that means they get funded for the next ~15 years. Lab B gets downsized or even shut down because the high energy physics money is going to lab A. If the project works -great. But if not, and Lab A has put in an unreasonably low estimate at least they still exist, and after 15 years many of the managers responsible have retired.

Now say 15 years later the $10B has been spent, but its not quite done, another $2B would let you finish the project. Do you really throw away $10B to save 2B? There is no fraud, just a mis-estimation of the costs of building a beyond state-of-the-art machine and slightly larger technical problems than were expected.

What happens is that you create a very strong motivation for under-estimates because that at least keeps the lab alive. Combine that with the difficulty of estimating the cost of something that hasn't been done yet, and a long enough project timescale that changing economic conditions can substantially change labor and construction costs. This is why many projects like this go over budget.

I don't think this is unique to government. I suspect that Boeing doesn't do a good job of estimating the development cost of a new airliner either - and that is much less of a technological extrapolation than the high energy physics machines.

Re:Peanuts

[mrspoonsi]

> the Iraq War took out one of the world's most evil tyrants

I am sure I saw George Bush on the news last week, alive and well...

>and removed a shit ton of weapons of mass destruction from the world

the US military would have restocked all the weapons of mass destruction ** used in Iraq by now.


** the Boston bomber was charged with having a weapon of mass destruction, so anything pressure cooker size and up must be one

Re:Peanuts

[TopherC]

I don't think in these cases you have multiple labs bidding for the job. You have multiple countries wanting to host the lab, but that's a different story.

The biggest problem for high energy physics is establishing multi-year funding. The US government cannot promise anything beyond a single year of funding. If say $8 B has been spent over 10 years and one year congress says "but I promised to cut spending", then that's the end of the road for that lab. This happened for the SSC in 1993, but also a lot of times since then on lower-profile, some $500 M experiments that were, yes, in construction already.

Now say 15 years later the $10B has been spent, but its not quite done, another $2B would let you finish the project. Do you really throw away $10B to save 2B? There is no fraud, just a mis-estimation of the costs of building a beyond state-of-the-art machine and slightly larger technical problems than were expected.

Most of the cases I'm familiar with, including the SSC, were not actually budget overruns even though they were politicized that way. If you're a politician who wants to (a) publicly demonstrate how fiscally conservative you are and (b) not actually cut spending on items that might affect the bulk of your constituency, then you cut big science every time. Even if the budget grows on the whole, you've made a statement and some headlines.

Why?

[pla]

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?

Re:Why?

[Bite The Pillow]

We don't yet know. Isn't that terribly exciting? That is basic research at its finest.

You need another one? So soon?

[bobbied]

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?

Re:You need another one? So soon?

[ivano]

They have their reasons if you actually read about it. Anyway it takes roughly 20 years to plan, get funding, and build the thing. That's why they're starting now. It's called "what happens if you only have one chance to build something that as yet the technology hasn't been developed yet". For instance the LHC was designed before they knew if they could find magnets to be able to "bend the beams". Also check out http://www.linearcollider.org/.

Crowd funding

[meta-monkey]

They should kickstarter the money for it. I'll throw in $50. Flex goals: Stargate; flux capacitor; warp drive.

Re:WHY NOT IN THE FIRST PLACE !!

[TopherC]

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.

Re:WHY NOT IN THE FIRST PLACE !!

[TopherC]

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.

Naming conventions for concentric circles

[DickBreath]

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.

Re:Question...

[TopherC]

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