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Re: 2017 Operation

Posted: Thu May 18, 2017 10:42 pm
by mfb
Fixed, beam is back.

Re: 2017 Operation

Posted: Sat May 20, 2017 12:02 am
by mfb
A bit behind schedule due to the water leak - still no bunch trains, but other tests got done. Stable beams potentially Sunday afternoon/night.

Re: 2017 Operation

Posted: Sat May 20, 2017 4:56 pm
by mfb
First bunch trains in the machine, 4 times 12 bunches per beam.
bunchtrains.png
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Re: 2017 Operation

Posted: Tue May 23, 2017 2:40 pm
by mfb
First stable beams of 2017.

The number of collisions per bunch is already close to the 2016 records. Scaled up to 2800 bunches we could get 170% the design luminosity.
stablebeams.png
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Re: 2017 Operation

Posted: Sun May 28, 2017 2:37 am
by mfb
Stable beams with 75 bunches, 3% the design luminosity.
We'll probably get more stable beams tomorrow, and scrubbing with just 72 bunches on Monday. The beam pipe must be really dirty if this is necessary.

Edit: Stable beams with 300 bunches, 15% design luminosity, in the night to Monday. Plan for today: Scrubbing. Sector 12 is "dirty" and has a high heat load.

Re: 2017 Operation

Posted: Mon Jun 05, 2017 12:15 am
by mfb
Stable beam with 600 bunches, 30% design luminosity.
0.13/fb delivered.

We'll see if the machine needs more scrubbing before going to 900 bunches. Last year it worked without.

The 2017 lumiplots are now there. Something is wrong with LHCb data.

Re: 2017 Operation

Posted: Mon Jun 05, 2017 12:00 pm
by dukwon

Re: 2017 Operation

Posted: Mon Jun 05, 2017 8:01 pm
by mfb
Weird, the second page has a much larger luminosity for ATLAS, with luminosity increases where we didn't have stable beams.

Re: 2017 Operation

Posted: Fri Jun 09, 2017 8:56 pm
by dukwon
lhc1.png
lhc1.png (23.01 KiB) Viewed 10378 times
About to scrub with 2820 bunches.

Re: 2017 Operation

Posted: Sat Jun 10, 2017 4:50 pm
by mfb
Running smoothly. 12 bunches more than the design value. 3.3E14 protons in a beam is a new record.

The plan is to go back to collisions on Monday.

Re: 2017 Operation

Posted: Sat Jun 10, 2017 10:00 pm
by tomey36
Is there anything of note that came out of the commissioning phase? Does everything look good compared to last year? I assume everything is going good, as they are ahead of schedule. It's just frustrating not having access to the morning meetings anymore

Re: 2017 Operation

Posted: Sun Jun 11, 2017 2:43 am
by mfb
I didn't see problems beyond the usual stuff that gets solved over time.
Scrubbing takes some time, but the heat load is getting better. Good enough for 900 and hopefully 1200 bunches. With 20 hours in stable beams each we get ~0.5/fb.

Edit: They'll go back to collisions Monday 9 am. A very short run with 10 bunches, then 3 hours of 600 bunches, then 900.

3.37E14/beam over night. This could be an absolute record of accelerated particles (at the same time) in any type of accelerator.

Edit2: Back to stable beams Monday morning. 10 bunches done, now we'll get 3 hours of 600.

Re: 2017 Operation

Posted: Wed Jun 14, 2017 7:46 pm
by mfb
We had stable beams with 980 bunches, 2/3 the design luminosity, nearly 0.15/fb in about 8 hours.

Pileup is higher than in 2016 already, something like 50 inelastic collisions per bunch crossing. At ~2000 bunches we surpass the 2016 record if the pileup conditions stay the same, at 2800 we get more than twice the design luminosity.

The current luminosity record for any type of collider is held by KEKB, at 2.11E34/(cm^2*s). Electron-positron machines have it much easier to achieve high luminosities (thanks to synchrotron radiation cooling the beams), but LHC could be the first proton-proton machine to get this record. Super-KEKB will probably need one more year before Belle-II can start taking data. After that it will dwarf even the HL-LHC luminosity, with up to 1E36/(cm^2*s) in a few years - but for a short time LHC could get the record.

Re: 2017 Operation

Posted: Sun Jun 18, 2017 1:03 am
by mfb
1550 bunches, and the LHC hit its design luminosity for the first time in 2017.

1.25/fb collected for ATLAS and CMS.

Re: 2017 Operation

Posted: Mon Jun 26, 2017 5:20 am
by sciing
A very productive week, with a new record for peak lumi. Now 2460 bunches in, is that the maximum?
I guess there is maybe also a new 24h record.
I hope mfb can give a short summary from the morning meeting.