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On Nov 30, they successfully cranked the beam energy up from 450GeV to 1.18TeV. So it's now officially the highest energy particle accelerator in operation in the world (The Tevatron, despite its boastful name, is only 0.98TeV):


In priniciple, they can crank the fucker all the way up to 14TeV, but for now they're going to leave it at 1.18TeV and start cranking up the luminosity. Calibration the rest of this month, and then if all goes well, they will crank the energy up again to 7TeV and do the first real physics experiments early in 2010. Again, it's supposed to go up all the way to 14TeV, but I don't know when they are planning on trying to pin the needle on the energy dial--maybe it's a good thing they are letting it run for a while and hopefully getting some data before breaking it again :) What a toy!

“I was here 20 years ago when we switched on CERN’s last major particle accelerator, LEP,” said Accelerators and Technology Director Steve Myers. “I thought that was a great machine to operate, but this is something else. What took us days or weeks with LEP, we’re doing in hours with the LHC. So far, it all augurs well for a great research programme.”

In other exciting (pre-)news, there are rumors afoot about some major news that may be about to break regarding dark matter... stay tuned. But if it's true things are staying remarkably hush. I'm on the edge of my seat... we live in truly fantastic times!



( 5 comments — Leave a comment )
Dec. 6th, 2009 07:59 pm (UTC)
Yeah, they've still got a lot to do before they reach "physics at 1.18 TeV", but progress so far has been huge... it seems like the basic process of injecting and circulating the beam is starting to become routine enough, and much of the past several days has been feeling out the aperture, lining up the collision geometry, and setting up machine safety systems (collimators, dump system, etc.) - things they couldn't really test until they had some detectable beam, but need to have working really well before the machine can safely handle much more than minimal intensity and produce interesing collisions: if they drop a "pilot" (4e9 protons) bunch on the inside of the beam line while exploring the aperture, no big deal... but the full "nominal" beam current (2800 bunches of ~1e11) can easily damage things if it goes off course!

They've just started trying multi-bunch beams: as of 6:30 this morning (CERN time - 9:30 last night here in CA) they had "4 on 4 circulating and colliding with reasonable lifetime in both beams" (at the 450 GeV injection energy level).

It looks like the next big hurdle is going to be getting a smooth, efficient ramp with good enough focus tracking that they don't spill too many protons on the way up... my guess is they'll probably work up that maneuver some more with the single "pilot" bunches they've been using, and then try ramping higher intensities once they've got that sorted out: that's gonna take a little refinement from what they've done so far:

They are indeed being -very- careful to be sure they get some data before they break it again!



They're not 100% sure that there are no further bad splices, but figure they should be safe at half current (6000 A vs. the normal 12000A in the main magnets), which is apparently the concern that's driving the present restriction to 3.5 Tev per beam (rather than going all the way to 7 just yet).
Dec. 6th, 2009 11:41 pm (UTC)
Also, minor correction - the ramps so far have reached 1.18 TeV for each beam - full nominal is 7 TeV beam energy (14 TeV "center of mass" collision energy); they're hoping to reach 3.5 Tev beam energy (7 TeV collision) soon and run physics for a while with that.
Dec. 7th, 2009 04:30 am (UTC)
Oh, thanks for pointing that out. I misread and assumed they meant 1.18 TeV center-of-mass energy; didn't realize it was per beam, that's even more impressive!
Dec. 8th, 2009 07:05 am (UTC)
The other impressive thing, besides the actual particle-acceleration and the sheer technical scale of the machine, is the organizational tenacity that allowed it to happen... the project was initially approved in December 1994, so 15 years from then to first collisions: that's very nearly the time required to complete the 200 in. telescope on Palomar (1928-1948, but interrupted by the war for about 3-4 years).

The LEP (Large Electron-Positron) machine mentioned in the article seems to have been a quickie by comparison - built 1984-1989, it only ran through November 2000 (when it was dismantled to make way for installing the LHC, which is installed in the same tunnel)...
Jan. 7th, 2010 06:49 am (UTC)
In other exciting (pre-)news, there are rumors afoot about some major news that may be about to break regarding dark matter...

You mean this?
( 5 comments — Leave a comment )


domino plural

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