Search found 135 matches

by PhilG
Sun Mar 20, 2011 6:00 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

They are starting on the 136 bunch fill now. This is an amazing rate of progress.
by PhilG
Sun Mar 20, 2011 11:11 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

pcatom, thanks. I understand that they will increase bunch numbers as 32,64,104,152,200. Will they go all the way with 8 bunch injections or switch to 24 bunch injection at some point? If the current smooth running continues they should easily make it to 200 before the next technical stop on 28th Ma...
by PhilG
Sun Mar 20, 2011 7:44 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

RocketManKSC, nice analysis although your extrapolation of the luminosity decay seems pessimistic. It should decay exponentially (perhaps faster at the start) The luminosity half life is about 15 hours. Theoretically the optimum runtime would be roughly 2 x sqrt(L*T) where L is the lifetime and T is...
by PhilG
Sat Mar 19, 2011 11:30 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

tomey36, that question was answered by pcatom about 10 posts back in this thread.

64 bunches now circulating, preparing to ramp
by PhilG
Sat Mar 19, 2011 7:13 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

They have been running with 32 bunches for peak luminosities of 33/ub/s. Already about 1/pb has been collected to add to the 40/pb from last year

They managed a turnround of only 2.5 hours between runs, much better than last year.

Objective for the week is 100+ bunches.
by PhilG
Tue Mar 15, 2011 7:39 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

Multi bunch injections yesterday looked very smooth. The coordination page indicates that they will start running with stable beams and increasing bunch numbers from Wednesday. Everything is following the planned schedule nicely. Yesterday I was watching live events from CMS but the muon trackers we...
by PhilG
Sun Mar 13, 2011 7:57 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

Todays morning report indicates that they are waiting on a decision to start stable beams. The collimator and beam dump have to give the all clear. http://lhc-commissioning.web.cern.ch/lhc-commissioning/news-2011/presentations/week10/2011.13.03-830meeting.pptx If we see stable beams today it may be ...
by PhilG
Sat Mar 12, 2011 7:29 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

This is copied from the CERN bulletin at http://cdsweb.cern.ch/record/1335119 LHC Report: Towards stable beams and collisions Over the past two weeks, the LHC re-commissioning with beam has continued at a brisk pace. The first collisions of 2011 were produced on 2 March, with stable beams and collis...
by PhilG
Sat Mar 05, 2011 9:26 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

@pcatom, thanks for the explanations
by PhilG
Thu Mar 03, 2011 10:14 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

Does anyone know what the "intermediate energy run" is and what it is for? They have planned it for a few days some time in April.
by PhilG
Wed Mar 02, 2011 10:33 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

Fingers crossed for some test collisions during the present fill.
by PhilG
Mon Feb 28, 2011 7:53 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

Over the weekend they succeeded in squeezing down to beta* of 1.5m . Remember last year they only went to 3.5m so this is a big step forward. It will at least double the luminosity. According to the Sunday morning meeting report there were some problems with changes in the crossing angle bump during...
by PhilG
Sat Feb 19, 2011 1:28 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

Re: 2011 Events Discussion

According to the coordination page they have injection studies this afternoon and first circulating beams tomorrow (Sunday 20th Feb)
by PhilG
Sat Feb 12, 2011 10:15 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 82780

2011 Events Discussion

The cryogenics page now indicates green status for all sectors while the coordination page indicates hardware commissioning and machine checkout are in progress until 21st Feb when we expect first beams for 2011, oh it just changed to "Prepare LHC for beam" with more details for next week: http://op...
by PhilG
Sat Feb 12, 2011 9:38 am
Forum: The Accelerator
Topic: Prospects for 2011 (via reuters)
Replies: 12
Views: 6057

Re: Prospects for 2011 (via reuters)

The latest Reuters summary is at http://www.reuters.com/article/2011/02/09/us-science-cern-idUSTRE7185AQ20110209 The plan is to stay at 3.5TeV during 2011. There is still a possibility to increase energy to 4TeV during 2012 if ongoing measurements indicate that it is safe. Otherwise higher energies ...