LHC portal

Here's the lumi situation as of the start of MD1:

Press release: https://press.cern/press-releases/2018/06/major-work-starts-boost-luminosity-lhc Press conference (skip to 43:00): https://webcast.web.cern.ch/event/i735865 Background to the HL-LHC: https://press.cern/backgrounders/faq-about-high-luminosity-lhc More on the civil engineering work: htt...

Global Post Mortem Event Event Timestamp: 10/06/18 21:39:22.990 Fill Number: 6773 Accelerator / beam mode: PROTON PHYSICS / STABLE BEAMS Energy: 6499200 [MeV] Intensity B1/B2: 14259 / 17073 [e^10 charges] Event Category / Classification: PROGRAMMED_DUMP / MULTIPLE_SYSTEM_DUMP First BIC input Trigge...

21:39 to 23:55 is 2 hours, 16 minutes. I believe the theoretical minimum turnaround time is about 1h45m.

8 quenches in S34. 12–15 hours to wait for cryo recovery

From what I've heard, it was shut down on purpose to do a special run for the liquid argon calorimeter. I'm not sure I believe that.

ATLAS requested the lower lumi. I'm guessing there's little point stressing the computing resources collecting high-pileup data with the magnet off. I'll try to find out what the problem with the magnet is, although I'm sure mfb will tell us soon enough.

Welcome!

The gruffalo with his hand on the beam dump switch

I think the "dark and foreboding" default stylesheet is rather off-putting to new users. I humbly suggest switching to "Flat style", which is lighter and looks more modern:

IIRC, it was first done in 2015 and has been routine since 2016.

https://lhc-commissioning.web.cern.ch/l ... ueeze.html

https://inspirehep.net/record/1469942/f ... pmw031.pdf

The figure of 300/fb was over Runs 1 to 3 (before the HL-LHC).

Look at the last few posts. 16L2 "woke up" and it took reduced beam intensity to get back to reliable stable beams. It was all going so well, too

It was seen during scrubbing that the intervention to remove frozen air did not eliminate the problem. The best tactic was found to be adding bumps and restricting the current through the appropriate magnet. The working theory is still that is frozen air or similar. If there is water ice in there it...

16L2 has returned with vengeance over the last 24 hours: 21:52 Programmed dump in stable beams to end fill 6681 22:01 to 00:09 SPS cavity trip 02:22 Back to stable beams 02:57 Dump (stable beams) 16L2 03:29 to 05:19 MKI2 fault 07:03 Dump (flat top) no reason given in logbook 10:46 Dump (ramp) 16L2 1...