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* Posts by James 107

5 posts • joined 4 Nov 2009

Collisions at LHC! Tevatron record to be broken soon?

James 107
Boffin

Many mouse clicks

> Intuitively, I would also think that two objects colliding at 450 each would equal a closing speed of 900 GeVs, but doesn't the theory of relativity contradict this, and suggest it's still 450?

Nope, the 450 GeV is a measure of energy, not velocity. Of course, in an accelerator, the two are correlated. As the energy goes up, the velocity gets closer and closer to the speed of light (but never actually to it).

With regards to it 'being a few mouse clicks' away. If only... There are many issues here. Firstly, we have only had one bunch of protons in each beam wanging around. When running at full tilt, there will be just under 4000 bunches per beam. We also need to fully commission the beam dump, beam cleaning (to avoid stray high-energy particles quenching magnets) system, feedback mechanisms that keep the orbits stable, make sure the response of all that is understood, etc etc etc and much more. This is all being done 'as we speak'. We're all hoping to crank up the energy-knob soon, but the machine needs to be understood first!

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LHC dimensional apocalypse from midnight: Your thoughts

James 107

Faster than a blinking eye...

While you were at the pub, the LHC has had circulating beams:

http://cmsdoc.cern.ch/cms/performance/FirstBeam/cms-e-commentary09.htm

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El Reg's LHC visit - Deleted Scenes

James 107

Control room

The CMS control room has a large collection of Apple desktops. And yes, I have an Apple laptop...

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Large Hadron Collider scuttled by birdy baguette-bomber

James 107

Number of dumps

And no, I'm talking about the result of eating too much fondue. A beam dump is a regular occurrence, and usually will happen at the end of each fill of protons, which will last about 12 hours. When the beam quality deteriorates (due to planned collisions, lateral dispersion, parasitic collisions with remaining gas in the beam pipe etc) too far, the beam gets dumped and a new one inserted.

So, these beam dumps are planned to last many years!

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Large Hadron Collider team flicks switch on Xeon grid

James 107

Servers on the other side of the planet?

Errm, that's what Grid computing does. The compute resource at CERN is only a small fraction of what we use:

http://lcg.web.cern.ch/LCG/

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