Search found 168 matches

by mfb
Mon Jun 27, 2016 6:48 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

Depends on the bunch structure. The PS can deliver up to 72 bunches without gap. Nominally the SPS accumulates four of those trains with a short gap of 8*25ns (not sure about the 8) in between (necessary for the SPS injection magnets), then injects them into the LHC, where a longer gap (28*25 ns) is...
by mfb
Mon Jun 27, 2016 11:29 am
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

New lumi record, Atlas 1.08 e34, design target reached. Even the average between ATLAS and CMS was slightly (~1%) above 1E34. They changed the SPS injection a bit, instead of one train with 72 bunches they injected two trains with 48 bunches each, that reduced the heat load on the LHC dipole magnet...
by mfb
Wed Jun 22, 2016 12:38 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

I swear i am not crazy, as of yesterday it wasn't included. How are you getting 6.1fb? The overview page shows 5.85fb for Atlas. If you include the current fill it would be ~6.3 fb. Just curious in case you know of a more accurate place for lumi data than the statistics page. I included the (then) ...
by mfb
Mon Jun 20, 2016 11:17 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

Huh? It is in the overview and also in the supertable for me. ~6.1/fb so far, 1.5 times the 2015 dataset. The combined 10/fb also mean that we should surpass the statistics of nearly every 8 TeV result now, as most cross sections increase by a factor of 2 or more. ATLAS shows 450/pb for the current ...
by mfb
Sat Jun 18, 2016 12:37 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

~3 last year, 5 this year, would be 7 to go in a month or less. Not impossible, but not easy either. But independent of the final number, it should be sufficient to see what happens to the diphoton excess. Some LINAC2 issues lead to a lower luminosity for the current fill, let's hope they fix that s...
by mfb
Fri Jun 17, 2016 1:55 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

Note that the July 15 is just the guess of this theorist. The experimental collaborations will have to see how much data they can include while keeping enough time for a proper analysis. We have two relevant data-points: - The Higgs discovery included data taken two weeks before the presentation was...
by mfb
Wed Jun 15, 2016 6:47 pm
Forum: The Accelerator
Topic: CMS and ATLAS luminosity: are they jealous?
Replies: 6
Views: 3251

Re: CMS and ATLAS luminosity: are they jealous?

The difference between the shown values is a few percent. The experiments are happy if the luminosity uncertainty towards the end of the year is a few percent, the online calibration is worse. The difference is probably just a different calibration, while both experiments really get a very similar l...
by mfb
Tue Jun 14, 2016 11:10 am
Forum: The Accelerator
Topic: LHC logbook access
Replies: 7
Views: 4403

Re: LHC logbook access

You don't need any account for the morning meeting slides as far as I know.
by mfb
Mon Jun 13, 2016 1:02 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

Wednesday is reserved for beta*=2.5 km runs, no relevant luminosity from that day probably, but apart from that: sure. Edit: >=24 hour run with 0.51/fb for ATLAS / 0.49/fb for CMS yesterday to today morning. Programmed dump after the luminosity was too low. CERN discusses some of those records 2/fb ...
by mfb
Sun Jun 12, 2016 6:16 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

The technical stop is over, and we directly got a record run! Started 0:20, dump is expected for 22:00 (in 2 hours), so the numbers will go up a bit more. - Luminosity record : ~8.6*10^33, 86% design luminosity, displayed by ATLAS - Integrated luminosity in 24 hours, in a single run, and within a da...
by mfb
Sun Jun 12, 2016 10:55 am
Forum: The Accelerator
Topic: How can the intensity be increased?
Replies: 3
Views: 1603

Re: How can the intensity be increased?

Unplanned dumps in stable beams are usually at random times and don't depend much on the previous time in stable beams. The risk to lose the next fill after an hour is not much larger than the risk of losing the current fill after an hour. Sure, it has to be taken into account because it makes the a...
by mfb
Sun Jun 05, 2016 1:01 am
Forum: The Accelerator
Topic: How stringent is the ~100fb for 2016-2018?
Replies: 7
Views: 2330

Re: How stringent is the ~100fb for 2016-2018?

2/(fb*week) is challenging - possible, but needs more than 50% of the time in stable beams (55% assuming an average of 6000 Hz/µb). Usually 1/3 is more realistic, for ~1.4/(fb*week), about the plan linked above.
by mfb
Thu Jun 02, 2016 10:15 pm
Forum: The Accelerator
Topic: What are the current records for LHC fills?
Replies: 45
Views: 14945

Re: What are the current records for LHC fills?

Some updated records: - Longest time in stable beams : 35 hours 24 minutes, the run mentioned in the last post. - Luminosity record : 7.9*10^33/(cm^2*s), or 79% design luminosity, by ATLAS yesterday evening and again this morning. CMS shows lower luminosity values, which is probably just a different...
by mfb
Thu Jun 02, 2016 11:49 am
Forum: The Accelerator
Topic: How stringent is the ~100fb for 2016-2018?
Replies: 7
Views: 2330

Re: How stringent is the ~100fb for 2016-2018?

It is still unclear how long repair of the SPS vacuum leak will take. We'll have to live with the gaps in the meantime - they are the time necessary to ramp up/down the kicker magnets for injection, so they cannot be shortened. They are 38 bunches long, so ideally we get 72 bunches per 110*25 = 2750...
by mfb
Thu Jun 02, 2016 11:23 am
Forum: The Accelerator
Topic: Dashboard tune plots seem... out of tune?
Replies: 4
Views: 1690

Re: Dashboard tune plots seem... out of tune?

The red line is not as problematic as the other lines (it just means horizontal and vertical tune are the same). If it hits one of the other lines, I don't think they can keep the beam.