2011 Events Discussion

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PhilG
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Re: 2011 Events Discussion

Post by PhilG » Wed Apr 27, 2011 6:56 pm

The 624 bunch filling scheme looks much more favourable for ATLAS and CMS with 598 collisions per turn vs only 424 in the 480 bunch scheme. Based on the 535/μb/s record from yesterday this implies a possible 535*598/424 = 750/μb/s

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DCWhitworth
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Re: 2011 Events Discussion

Post by DCWhitworth » Wed Apr 27, 2011 9:22 pm

PhilG wrote:The 624 bunch filling scheme looks much more favourable for ATLAS and CMS with 598 collisions per turn vs only 424 in the 480 bunch scheme. Based on the 535/μb/s record from yesterday this implies a possible 535*598/424 = 750/μb/s
Close - about 730 :)
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DCWhitworth
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Re: 2011 Events Discussion

Post by DCWhitworth » Wed Apr 27, 2011 9:38 pm

photino wrote:4-sigma signs of a nonstandard 115 GeV Higgs... in a leaked memo from ATLAS?
http://resonaances.blogspot.com/2011/04 ... maybe.html
It's made it to the BBC website now - http://www.bbc.co.uk/news/science-environment-13198701
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DCWhitworth
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Re: 2011 Events Discussion

Post by DCWhitworth » Wed Apr 27, 2011 10:00 pm

DCWhitworth wrote:
PhilG wrote:The 624 bunch filling scheme looks much more favourable for ATLAS and CMS with 598 collisions per turn vs only 424 in the 480 bunch scheme. Based on the 535/μb/s record from yesterday this implies a possible 535*598/424 = 750/μb/s
Close - about 730 :)
Or perhaps not - viewtopic.php?f=4&t=895
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PhilG
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Re: 2011 Events Discussion

Post by PhilG » Thu Apr 28, 2011 5:56 am

I was watching closely and it reached 737 for ATLAS and 660 for CMS, whichever is correct its a nice step up.

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PhilG
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Re: 2011 Events Discussion

Post by PhilG » Mon May 02, 2011 9:03 am

With 768 bunches peak luminosity is now over 900/ub/s in ATLAS and 830/ub/s in CMS.

The next step should take them beyond the 1000/ub/s target luminosity wanted for this year, but that will probably be after the next technical stop. Present scheme has 700 colliding bunches. This will be doubled if they fill with maximum 1404 bunches so 1700/ub/s should be possible.

Integrated luminosity delivered is now about 320/pb, enough for some interesting physics I hope.

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ikarus177
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Re: 2011 Events Discussion

Post by ikarus177 » Mon May 02, 2011 5:59 pm

Does anybody know what the "unsqueeze"-tests are good for?

Currently, b* is about 90m in CMS... (but with no beam in the machine)

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Re: 2011 Events Discussion

Post by pcatom » Mon May 02, 2011 6:36 pm

Does anybody know what the "unsqueeze"-tests are good for?

Currently, b* is about 90m in CMS... (but with no beam in the machine)


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The 90m beta* optics is requested for Totem and Alfa. The first studies (with beam) will take place during the MD session starting on Wednesday.

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Re: 2011 Events Discussion

Post by tomey36 » Mon May 02, 2011 7:36 pm

what are teh SEE's and SEU's that have been causing them so much trouble?

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Re: 2011 Events Discussion

Post by Kasuha » Mon May 02, 2011 9:27 pm

tomey36 wrote:what are teh SEE's and SEU's that have been causing them so much trouble?
http://en.wikipedia.org/wiki/Radiation_ ... amage:_SEE

SEE = single-event effect
SEU = single-event upset, a kind of SEE

Generally some of their machines are malfunctioning due to radiation which they need to prevent.

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Re: 2011 Events Discussion

Post by Stephen » Tue May 03, 2011 4:03 pm

I have a question for you guys - what was the energy of the Pb + Pb collisions in this last November? And at what energy are they going to perform Pb + Pb collisions in 2014?

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Re: 2011 Events Discussion

Post by Kasuha » Tue May 03, 2011 4:45 pm

Stephen wrote:I have a question for you guys - what was the energy of the Pb + Pb collisions in this last November? And at what energy are they going to perform Pb + Pb collisions in 2014?
1.38 TeV per nucleon, i.e. 287 TeV per lead nucleus in each beam. That corresponds to 3.5 TeV per proton charge.
In 2014 it should be twice as much.

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Re: 2011 Events Discussion

Post by ikarus177 » Sat May 07, 2011 9:49 am

Does anybody know what ATS means (they are doing "ATS MD" right now)?

Kind regards

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Re: 2011 Events Discussion

Post by LarryS » Sat May 07, 2011 12:19 pm

Achromatic Telescopic Squeezing Machine Development … whatever that is!

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PhilG
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Re: 2011 Events Discussion

Post by PhilG » Sat May 07, 2011 7:31 pm

There is an excellent new page with data on all the fills

https://lhc-statistics.web.cern.ch/LHC-Statistics/

Use the "Fill Summaries" tab to get all this years fills.

(comparing with my notes I think that 1745 and 1715 are missing)

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