Search found 100 matches

by Bornerdogge
Sat Jun 18, 2011 9:47 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

Looks like they're going for the next step - 1236b - this afternoon, at last!
by Bornerdogge
Thu Jun 09, 2011 5:05 pm
Forum: The Accelerator
Topic: Luminosity drop
Replies: 2
Views: 896

Re: Luminosity drop

Oh right, thanks, I forgot that L ~ I²...

Was there a particular reason to push the intensity down by 10%? Too many UFOs I guess?
by Bornerdogge
Thu Jun 09, 2011 4:18 pm
Forum: The Accelerator
Topic: Luminosity drop
Replies: 2
Views: 896

Luminosity drop

Hi, I think this speaks for itselft: http://cms-service-lumi.web.cern.ch/cms-service-lumi/publicplots/lumipeak-2011.png Peak lumi's been dropping steadily and is now around the peak lumi they got with 912 bunches, though they have more than 100 more in the machine... The beam currents are a little b...
by Bornerdogge
Sun Jun 05, 2011 12:17 pm
Forum: Science
Topic: Proton mass increase
Replies: 7
Views: 5211

Re: Proton mass increase

It it not quite correct to say the proton mass has increased... Special relativity modifies Newton's law F=ma, and in this particular case it is as if the proton mass had increased by the relativistic factor gamma. But the proton itself has not become "bigger"...
by Bornerdogge
Fri May 27, 2011 9:11 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

At last stable beams!

Hey, the scale of the luminosity axis on the LHC dashboard reaches from 0 to 1664 s/µb...
I think that's made by purpose (cf. french beer brand) XD
by Bornerdogge
Thu May 26, 2011 8:52 pm
Forum: The Accelerator
Topic: The cost of days without runs
Replies: 5
Views: 1434

Re: The cost of days without runs

Isn't it possible to take advantage of this recovery time to work on some other independent parts of the machine?

For example right now they are performing "rf interlock tests" while the cryo is recovering...
by Bornerdogge
Thu May 26, 2011 4:38 pm
Forum: The Accelerator
Topic: The cost of days without runs
Replies: 5
Views: 1434

Re: The cost of days without runs

Hard to guess... It is direct cost due to the repairs or indirect cost due to the inactivity?
by Bornerdogge
Tue May 24, 2011 9:54 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

Does anybody know when they're moving for the next step?

There's nothing on the plan and if my memory's right they've already passed the (3 good fills && 20 hours) of stable beams with 912b.

Or do they want to run for a time with 912b to see how things are doing, like they did with 768b...
by Bornerdogge
Thu May 19, 2011 8:05 pm
Forum: The Accelerator
Topic: Newbie: Lumi difference between Atlas and CMS
Replies: 10
Views: 2295

Re: Newbie: Lumi difference between Atlas and CMS

Since the new VdM scans the difference disappeared.

If I remember well the lumi in CMS was even slightliy higher than in ATLAS...
by Bornerdogge
Mon May 16, 2011 10:13 am
Forum: The Accelerator
Topic: Facebook page
Replies: 15
Views: 54084

Re: Facebook page

Xymox wrote:So everybody go to facebook
I'm sorry... No.
by Bornerdogge
Tue Apr 26, 2011 9:40 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

The planning says they're going for stable beams with 640 bunches this afternoon...

This would yield between 650 and 750 (µb)-1, depending on the filling scheme.

Good luck guys!
by Bornerdogge
Thu Apr 21, 2011 10:07 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

Great! :clap: They doubled luminosity in a single week!!

Do you happen to know why the lumi in CMS is always ~10% lower than in ATLAS, though the squeeze is tighter and the number of colliding bunches is the same?
by Bornerdogge
Thu Apr 21, 2011 9:18 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

DCWhitworth wrote:Thought they'd make it easily but they only squeezed to 2m not 1.5m
That's why I said that; I didn't check during the fill...

Thanks for your explanation!

They're filling again and the intensities seem slightly higher...
by Bornerdogge
Thu Apr 21, 2011 7:23 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

I was hoping for 500/ub/s easily with 480. Intensity could be higher. Perhaps the next fill will be better. Going up in 144 bunch steps is good. Yes it is a bit disappointing indeed. Perhaps because of the slightly lower bunch intensities (1.1e11 in state of ~1.25e11 for the first runs with 336b).....
by Bornerdogge
Sat Mar 26, 2011 11:56 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 34584

Re: 2011 Events Discussion

Does anybody know the purpose of the current 1.38TeV run?