A Detailed Profile of the Hadron Super Collider

davco9200 writes "The New York Times has up a lengthy profile of the Large Hadron Collider. The article covers the basics (size = 17 miles, cost = 8 billion, energy consumption = 14 trillon electron volts) and history but also provides interesting interviews of the scientists who work with the facility every day. The piece also goes into some detail on the expected experiments. 'The physicists, wearing hardhats, kneepads and safety harnesses, are scrambling like Spiderman over this assembly, appropriately named Atlas, ducking under waterfalls of cables and tubes and crawling into hidden room-size cavities stuffed with electronics. They are getting ready to see the universe born again.' There are photos, video and a nifty interactive graphic."

BETTER HADRON COVERAGE

[mattnyc99]

This stuff is pretty cool, but The New Yorker's incredible science writer (who basically told the rest of the world about global warming) had a more in-your-face profile of the LHC [newyorker.com] last week, and Popular Mechanics has officially dubbed it "The World's Biggest Science Project." [popularmechanics.com] Sweet.

Re:"Energy Consumption" - WTF?

[phaunt]

From TFA:

Everything about the collider sounds, well, large -- from the 14 trillion electron volts of energy with which it will smash together protons (...)

So that energy is not the consumption (which would be more usefully measured in Watts anyway, as you point out), but the energy the particles have when they collide (which is usually measured in (T)eV).

/. does it again!

[perturbed1]

There are more mistakes in the /. gist than in the NYTimes article -- which incidentally is a good summary for the LHC. Well, the writer was at CERN about a month ago, so I am assuming it took about that long to write it.

It is called the LHC -- Large Hadron Collider. Not the Hadron SuperCollider. The SuperCollider [slashdot.org] is dead. It was called the SSC. But it has passed on. It has ceased to be! It has expired and gone to meet its maker! Its a stiff! Bereft of line and rests in peaces in TX! It's kicked the bucket and shuffled off its mortal coil! (Gee. I wish I could write this about the M$! Grrr!!)

The energy consumption is 14 trillion electron volts?! Wt..? Last time, I checked the LHC could not run on days where the electricity prices were high. Actually, it can not run during winter for that reason. It and the detectors consume as much energy as you get out from a medium-sized nuclear reactor -- and that's why it sits partially in France and not fully in Switzerland. (France produces a whole lot more power than Switzerland.)

"The piece also goes into some detail on the expected experiments. " Huh? What expected experiments? The experiments have been in construction now for seven years. You mean expected results?!

Honestly, how many mistakes can you make in one paragraph??

Sorry about the rant, but I am so annoyed with the latest reports about M$'s threats, that I had to vent. I feel better now. Slightly.

Re:"Energy Consumption" - WTF?

[Jamu]

Or to put it another way: the LHC is not 100% efficient and can't be powered with a single postgrad and a bicycle generator. The true power consumption of the LHC will be about 120 MW.

Two 7TeV Beams = 14TeV collision

[perturbed1]

14 TeV is the amount of energy that is in a collision from two 7TeV beams colliding. In this case, the beam means particles (protons) accelerated to carry 7TeV of momentum. But that's just one "particle". The LHC, there are many "buckets" of particles being stored and collided and the total stored energy around the whole ring is 360MegaJoules. It is fairly easy to calculate actually:

There are 2808 bunches around the ring, each containing 1.15x10^{11} protons each with 7TeV of momentum. 7TeV = 7x10^{12} x 1.602x10^{-19} Joules. You multiply it all out, you get 362MegaJoules stored in the beam around the LHC ring.

That's 1 small cruise ship of 10,000 tons moving at 30km/hour.

450 automobioles of 2tons moving at 100km/hour.

Is enough to melt 500kg of copper. (which is actually a worry if the beams "are lost" due to a magnet quench and they hit the vacuum pipe!)

Oh, btw, the power consumption of the LHC only (excluding the detectors) is ~120MW.

Re:"Energy Consumption" - WTF?

[anzev]

This really is a strange figure. It might reference anything but the consumption, most notably, the "energy" inside the ring. Or maybe the consumption of ONLY the ring itself, becaue when you start looking at the magnets, and vacuum pumps, and control system infrastructure you quickly find out that you need to be connected to at least 2 power grids :-). At least that's the case with DESY if I remember correctly.

Re:Power consumption = 14 Tev... ORLY?

[Oink]

Actually, what you said is not quite correct either. That's the center of mass collisional energy. Individual particles can reach half that, or 7 TeV.

Pictures of the "mundane" parts here

[iamlucky13]

Here is a map [web.cern.ch] showing the layout of the LHC. It actually consists of two rings and a couple of linear accelerator stages so they aren't injecting cold particles into the high energy beam. Keep in mind, the main ring is 17 miles around and about 100 meters underground. A lot of the people living inside its circumference probably don't actually realize what's going on underneath their feet, other than the various CERN campuses spread around the ring and all the nerdy looking people going in and out. In fact, there will be millions of particles whizzing around the track at ~99.9999% the speed of light...circling the entire distance 10,000 times a second.

What you see in the NY Times slide show is basically the most impressive parts of the LHC, the incredibly complex and massive detectors assembled in huge underground vaults. The remainder, while still fairly complicated and interesting, is orders of magnitude simpler.

The rest of the collider is mostly a 3 meter diameter tunnel (pic) [web.cern.ch], which has a track for getting people and equipment around it as needed, and the beam conduit. The physical tunnel is being reused from an older collider that was retired in 2000 to make way for this one, and I presume was dug with a tunnel boring machine.

The conduit (CAD rendering) [web.cern.ch] itself is more than just a pipe. The most important part is the two vacuum pipes inside that the beam runs through, and the 9,000+ magnets around the pipes that electromagnetically constrain and accellerate the particles so they follow the 17 mile loop instead of smashing uselessly into the walls. It also contains the electrical lines that power the magnets, and helium lines that keep them cool. Some stray collisions are expected, so it also contains a little bit of radiation shielding, although I don't believe people are supposed to be in the tunnel when it is operating.

More Pictures [web.cern.ch]
LHC Outreach Page [web.cern.ch]
Map showing cities and Swiss/French border [web.cern.ch]

Corrected summary

[l0b0]

Circumference = 27 kilometers (~17.5 miles), cost = 8 billion USD (presumably, and only for the construction), energy consumption = ~120 MW, particle energy = 14 TeV.

More interesting statistics [web.cern.ch] are available on the LHC outreach site.

What a half-assed attempt at a submission. Even the title is a mix between the SSC [bbc.co.uk] and the LHC.

Re:Please stop talking about power/energy!

[treeves]

No. 14TeV is the energy of a single hadron, not the energy involved on the whole LHC.

So if the beam had a current of 1 amp (1 Coulomb / sec) then the energy of the particles in the beam would be 6.241×10^18 * 7x10^-13 = 4.3*10^6 kW*Hr. That's a lot of energy, and I'm guessing the beam currents are MUCH less than 1 amp. BTW, power = energy / time or work / time.

Mods are clueless on this one.

Re:The Problem with Something this Expensive

[Dirtside]

Tang was created in 1957 or so, and had nothing to do with the space program until they started using it during Gemini.

That aside, the answer to your question is that we don't know what we're going to learn from projects like this. But we do fundamental research like this anyway, for a variety of reasons best expressed by this article [math.mun.ca].

Re:"Energy Consumption" - WTF?

[Rich0]

I hate to be pedantic, but I think a given electron crosses the property line in your direction once every cycle - not half-cycle.

Let's start a zero voltage with the electron right on the border of your property. The voltage rises to 110/220, and the electron moves towards your house and you "buy" it. Voltage drops to zero and it comes to a halt inside your house somewhere. Voltage drops to -110/220 and the electron moves away from your house. Voltage rises to zero just as the electron crosses your property line and is "returned" to the utility. Thus completes one cycle.

The same logic applies wherever the electron starts out.

Re:"Energy Consumption" - WTF?

[cyberanth]

It means the particles in the collider are accelerated up to 14TeV; energy is the relevant parameter in high energy physics, strangely enough. If the Higgs weighs 140 GeV for instance, we need to accelerate particles in the collider to more than that energy to produce one.

Re:Cool

[Enlightenment]

It's not. It's measured in electron volts. 1 electron volt is equal to the charge on an electron (absolute value) times 1 volt. A volt is a unit of energy per unit charge, so (Energy/Charge)*Charge = Energy. Or if you want to know it in joules, 1 Volt = 1 Joule/Coulomb and the charge on an electron is 1.60*10^-19 Coulombs, so 1 eV = 1.60*10^-19 Joules. So that means they're measuring mass in terms of energy--which is fine, if you remember your Einstein.