Current Events Discussion

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

Post by LarryS » Fri Apr 23, 2010 10:57 pm

It is 24-04-2010 at 00:55 and they are beginning a Physics ramp BUT this time with 3 bunches in each beam.

This should improve the collision rate (luminosity) as they now have more protons.

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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Fri Apr 23, 2010 11:02 pm

It's going to be the first squeezed physics run I think.
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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Fri Apr 23, 2010 11:05 pm

Ver Greeneyes wrote:With squeezing tests going well, it seems they decided to do something a bit more adventurous: introducing the squooze! :)
I'm sure AA Milne came up with the squooze or certainly a squoze.
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Harbles
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Re: Current Events Discussion

Post by Harbles » Fri Apr 23, 2010 11:29 pm

I hope this is appropriate place to post this if not move it somebody.

Heli-good presentation on the commissioning from Jan till Apr 20. And the future at the LHC. All your questions answered.
http://cdsweb.cern.ch/record/1260487

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jmayes
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3x3 @ 3.5Tev

Post by jmayes » Sat Apr 24, 2010 12:49 am

3x3 @ 3.5Tev Going now!

Unless I missed something, this is a new Milestone!
:clap: :lol: :dance: :crazy:

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LarryS
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Re: Current Events Discussion

Post by LarryS » Sat Apr 24, 2010 1:33 am

Milestone??? That's not metric.

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jmayes
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Re: Current Events Discussion

Post by jmayes » Sat Apr 24, 2010 1:53 am

From P1; SQUEEZED STABLE BEAMS!!

Yes, I do think this is a "*Stone" for sure.
:dance: :dance: :dance: :dance:

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LarryS
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Re: Current Events Discussion

Post by LarryS » Sat Apr 24, 2010 2:14 am

Notice the second bucket in each beam does not line up (8941 vrs 8911); this will affect luminosity.

pixelmasseuse
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Re: Current Events Discussion

Post by pixelmasseuse » Sat Apr 24, 2010 2:17 am

ehh, I was wondering about that... perhaps they want 1 bucket per beam to go through all the motions, but not collide...

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Tau
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Squeezed stable beams

Post by Tau » Sat Apr 24, 2010 7:49 am

With this fill (the squeezed stable beams of 24 april) they have ten times the luminosity they had before.
That means that this single fill gives about as many collisions as all the previous runs together. :clap:
- Tau

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PhilG
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Re: Current Events Discussion

Post by PhilG » Sat Apr 24, 2010 8:30 am

They have to use these odd looking bunch numbers because of the awkward positioning of LHCb. The bucket numbers now being used will give 2 collisions per circuit of the beams for each experiment, compared with 1 collision before.

see http://blog.vixra.org/2010/04/24/lhc-ac ... zed-beams/ for some details.

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DCWhitworth
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Re: Current Events Discussion

Post by DCWhitworth » Sat Apr 24, 2010 7:40 pm

I don't know if anyone noticed, but briefly between the later stages of the ramp and the early stages of the squeeze the LHC had it's first 'unsafe' beams.
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Harbles
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Re: Current Events Discussion

Post by Harbles » Sat Apr 24, 2010 9:19 pm

I think the term Unsafe Beams refers to all beams above this intensity. If they had lost control of a beam at lower intensities no damage would be likely to occur. But now that they have more confidence in machine protection devices they better not loose control as they would likely have significant damage.

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Re: Current Events Discussion

Post by tomey36 » Sun Apr 25, 2010 12:40 am

stable squeezed beams for 24 hours! :dance:

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mrgumby
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Re: Current Events Discussion

Post by mrgumby » Sun Apr 25, 2010 4:39 am

yeehaa!!!!!

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