Current Events Discussion

The place to discuss the LHC. Commissioning, operation, issues, events ....
Kasuha
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Re: Current Events Discussion

Post by Kasuha » Fri Jul 16, 2010 6:38 pm

MpVpRb wrote:So...I'm still confused about inverse xxbarns.

If smaller numbers mean more data, why do the numbers increase over time on these plots?

http://lpc.web.cern.ch/lpc/lumiplots.htm
You are wrong - smaller numbers do not mean more data. It's the change of unit that makes the change. Let's take another example:
You walk from point A to B and back. On the way from A to B find ten dollars every kilometer. On your way back, you find a dollar every meter. On which way did you find more money?

The graph keeps increasing because it's in just one unit, (collisions per) inverse nanobarn. You can recalculate them to femtobarns too but at current stage the numbers would be ridiculously small so it's better to stick to nanobarns.

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PhilG
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Re: Current Events Discussion

Post by PhilG » Sun Jul 18, 2010 9:30 am

The current run had a peak lumninosity of 1.6 MHz/barn, about 10% better than previous records.
I think there will a technical stop from Monday for a couple of days. When it returns they are likely to go for more bunches, maybe 24.

tomey36
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Re: Current Events Discussion

Post by tomey36 » Sun Jul 18, 2010 7:46 pm

it looks like the LHC had a good week lots and lots of collisions. Atlas almost has 10 billion recorded so far!

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CharmQuark
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Re: Current Events Discussion

Post by CharmQuark » Sun Jul 18, 2010 8:00 pm

love it :thumbup:
Anyone who doesn't take truth seriously in small matters cannot be trusted with large ones either by Albert Einstein.

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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Tue Jul 20, 2010 12:29 pm

Next up looks to be completing commissioning of multi-bunch injection. Another important step in ramping up the intensity.
DC

The LHC - One ring to rule them all !

oxodoes
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Re: Current Events Discussion

Post by oxodoes » Tue Jul 27, 2010 11:30 pm

Wow this has been one remarkable day. Since the technical stop the startup seemed to proceed rather slowly, but today we got perfect multibunch (4 bunch) injections for both beams. In total 24 nominal bunches were injected into each beam giving a record intensity of about 2.2E12. The beam were dumped shortly afterwards so one can only dream about the potential lumi....

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CharmQuark
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Re: Current Events Discussion

Post by CharmQuark » Wed Jul 28, 2010 12:15 am

This pleases me :thumbup:
Anyone who doesn't take truth seriously in small matters cannot be trusted with large ones either by Albert Einstein.

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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Thu Jul 29, 2010 10:09 am

Heads up ! Page 1 says 25 bunches in the next physics fill ! :dance:
DC

The LHC - One ring to rule them all !

tomey36
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Re: Current Events Discussion

Post by tomey36 » Thu Jul 29, 2010 8:05 pm

does any one know how many collisions per site this fill will bring?

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morgad
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Re: Current Events Discussion

Post by morgad » Thu Jul 29, 2010 8:12 pm

They have called the filling scheme Multi_25b_16_16_16_hyb - so I assume 16 collisions per site

best regards
Dave

tomey36
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Re: Current Events Discussion

Post by tomey36 » Thu Jul 29, 2010 8:30 pm

thank you morgad ;) isn't that double what that had before? very exciting stuff!

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CharmQuark
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Re: Current Events Discussion

Post by CharmQuark » Thu Jul 29, 2010 8:59 pm

I'm excited tonight :oops:
Anyone who doesn't take truth seriously in small matters cannot be trusted with large ones either by Albert Einstein.

tomey36
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Re: Current Events Discussion

Post by tomey36 » Thu Jul 29, 2010 9:57 pm

stable beams!!!!

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CharmQuark
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Re: Current Events Discussion

Post by CharmQuark » Thu Jul 29, 2010 9:59 pm

Thats what i like to see :thumbup:
Anyone who doesn't take truth seriously in small matters cannot be trusted with large ones either by Albert Einstein.

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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Thu Jul 29, 2010 10:26 pm

Wow, luminosity over 2.5 at the start of this run.
DC

The LHC - One ring to rule them all !

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