Search found 135 matches

by PhilG
Thu Jun 16, 2011 9:17 pm
Forum: The Accelerator
Topic: MD
Replies: 2
Views: 2678

Re: MD

The schedule was changed, next MD starts 29th June.
New schedule is at https://espace.cern.ch/be-dep/BEDepartm ... hedule.pdf
by PhilG
Thu Jun 16, 2011 2:58 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83837

Re: 2011 Events Discussion

Just now the LHC surpassed 0.5 fb^-1 integrated luminosity delivered to CMS. Current fill of 32 pb^-1 plus the 468 ps^-1 stated here https://twiki.cern.ch/twiki/bin/view/CMSPublic/LumiPublicResults Just 17 days later and they have doubled that to 1/fb https://lhc-statistics.web.cern.ch/LHC-Statisti...
by PhilG
Thu Jun 09, 2011 4:47 pm
Forum: The Accelerator
Topic: Luminosity drop
Replies: 2
Views: 2464

Re: Luminosity drop

The beam intensity has been allowed to slip down by nearly 10%. You can see the intensity plots on the statistics page if you click on the fill numbers. https://lhc-statistics.web.cern.ch/LHC-Statistics/ A 10% drop in intensity gives a 19% drop in luminosity because of the square dependency. I think...
by PhilG
Sun Jun 05, 2011 11:48 am
Forum: The Accelerator
Topic: UFO
Replies: 4
Views: 3995

Re: UFO

Morning report says they changed some UFO monitoring levels.
If only all the problems could be fixed so easily
by PhilG
Sat Jun 04, 2011 6:46 pm
Forum: The Accelerator
Topic: UFO
Replies: 4
Views: 3995

Re: UFO

The number of dumps due to UFOs (Unidentified Falling Objects) has increased dramatically since they got to 1092 bunches. It is the most common cause of beam dumps now. http://lhc-commissioning.web.cern.ch/lhc-commissioning/news-2011/presentations/week22/mike-fills-gt-450-june11.pptx Is this just du...
by PhilG
Wed Jun 01, 2011 5:27 am
Forum: The Accelerator
Topic: Are all interfaces to the ring optically coupled?
Replies: 9
Views: 5003

Re: Are all interfaces to the ring optically coupled?

How can you measure the cost of downtime? The LHC does not produce a product that can be given a value in dollars.The loss is in terms of scientific data. In direct money terms the LHC probably saves loads of cash when it goes down because they save on electricity. That is a high cost greater than t...
by PhilG
Mon May 30, 2011 7:15 pm
Forum: The Accelerator
Topic: Target integrated luminosity for 2011
Replies: 3
Views: 2798

Re: Target integrated luminosity for 2011

They should just keep going and collect as much data as they can. More data means more discovery potential.
by PhilG
Sat May 28, 2011 9:08 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83837

Re: 2011 Events Discussion

Thanks @pcatom, that makes sense.
by PhilG
Sat May 28, 2011 6:41 pm
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83837

Re: 2011 Events Discussion

New record fill of 31.5/pb and in just 10 hours. They could have done more but cut short to go to the next step. In an uncharacteristic change of plan they are skipping the 1056 bunch scheme and aiming for 1092 bunches. It is not clear if they will still do the 1200 bunch step or jump straight to a ...
by PhilG
Tue May 24, 2011 4:36 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83837

Re: 2011 Events Discussion

The luminosity seems kind of low for 912 bunches, any one know why? Possibly some losses at injection and maybe some emittance blow-up. They are going to adjust one of the injection collimators TCLIB so that might fix it. Still they have had record peak luminosity of 1100/ub/s and now record total ...
by PhilG
Mon May 23, 2011 7:14 pm
Forum: The Accelerator
Topic: Possible LHC convention!!!!
Replies: 15
Views: 13486

Re: Possible LHC convention!!!!

All sounds good. I think we need some possible dates to know if we can make it.
by PhilG
Mon May 16, 2011 11:17 am
Forum: The Accelerator
Topic: 2011 Events Discussion
Replies: 184
Views: 83837

Re: 2011 Events Discussion

Physics runs are back after the technical stop. They are now running with 228 bunches and will step up through 480 and 768 bunches to get back to previous luminosities. After two more good fills with 768 bunches they can move up to 912 bunches, but that will require a new injection setup for 108 bun...
by PhilG
Fri May 13, 2011 6:37 am
Forum: The Accelerator
Topic: Improved performance after MD and TS?
Replies: 11
Views: 5843

Re: Improved performance after MD and TS?

Quenched and Dumped are not the same thing. I think you are interested in cases where the beam has to be dumped before the run is complete. This happens for lots of reasons. A quench is a more serious event where the energy in the magnets has to be dumped quickly. There are some important difference...
by PhilG
Thu May 12, 2011 9:08 pm
Forum: The Accelerator
Topic: Improved performance after MD and TS?
Replies: 11
Views: 5843

Re: Improved performance after MD and TS?

If the question is about performance perhaps it should have been about any premature end to a fill, not just quenches.
by PhilG
Tue May 10, 2011 11:22 am
Forum: The Accelerator
Topic: Improved performance after MD and TS?
Replies: 11
Views: 5843

Re: Improved performance after MD and TS?

pcatom wrote:
Is that enough detail??
Excellent, Thanks for the clarification