Current Events Discussion

[PhilG]

From the plan...
Goals:
1- complete the longitudinal emittance blow up commissioning - DONE
2- continue the transverse damper commissioning - DONE
3- robust ramp for 1e10 - DONE
4- commission the squeeze with separated beams , squeeze to 3.5 m - DONE
5- OFB, BPM, reference orbit - DONE
6- Collimator setting-up - IN PROGRESS
7- Injection and beam dumping system qualification - IN PROGRESS

That looks good. If all goes as well for another week they will be ready to start physics with nominal bunches.

[tomey36]

next fill for physics!!!!!!

[PhilG]

Havn't seen that for a while!
Hope its high intensity bunches and not a fallback to previous physics setup.

[tomey36]

fill shows high intensity if all goes wel the lhc will break another record!

[Bornerdogge]

High intensity stable beams in progress!!!!

I see a 2.5e29 /cm²/s right now!

The LHC team has really done a great work in order to establish high intensity stable beams so fast!
I hope they'll be able to increase the number of bunches just as fast!

[Harbles]

#Cern #lhc Stable Beams * first time with nominal bunches!
Log at 1:36 Thu 24-06-10 Night


http://bit.ly/dw8UnP

[jmayes]

This is great! Finally some action, was tough trying to keep up but know it all has to be done

Too bad, did not last long but sure we will see plenty of fireworks shortly!

[mrgumby]

yes!!!!

[Harbles]

and 4 stringyness i repost here.

June 25 2010 update
http://indico.cern.ch/conferenceDisplay.py?confId=98966


the plan...
Commissioning almost complete
Beginning July start with 3x3 bunches and gradually increase weekly to 6x6,12x12, 24x24 by the end of july.
Stable run under constant conditions all of August.
Bunch Train operation in September.

Bunch Train Operation?
http://accelconf.web.cern.ch/accelconf/ ... EP4A12.pdf
Quote:
V. I. Balbekov has computed the tune shift along a
uniform train or batch of proton bunches for the high
intensity UNK machine [1]. The origin of this effect is
the complex transverse resistive wall impedance. It is
computed here both for the SPS (fixed target and LHC
beam operation) and for the LHC. It modifies the stability
situation of the bunch train when compared to a machine
which is uniformly filled. In the latter part of the paper it
is shown that the driving force of the resistive wall
instability depends critically on the batch length for
constant local density.

[PhilG]

Record luminosities again, 5 x 10^29 Hz/cm^2

[PhilG]

STABLE BEAMS lasted 14 hours. This must have provided at least 10 inverse-nanobarns in one run! The total integrated luminosity up to this point was about 20 inverse nano-barns. This run justifies the break from physics runs to get high intensity bunches working. Hopefully there will be another similar run or two this weekend.

Recap and plans at http://blog.vixra.org/2010/06/25/lhc-recap-and-plans/

[photino]

Back to physics - in style!

Thanks for that helpful blog post Philg!

[jmayes]

Got another good one going on right now! 8+ hrs @ 3e11x3, Woopie!

[PhilG]

They started with even higher bunch intensities this time, 120 billion ppb, luminosities therefore a little higher.
The coordination vista indicates a planned jump to 6x6 bunches on Thursday.
The sudden losses might be a bit of a concern though.

[Tim Bergel]

But this time they lost the beams due to a dump caused by a lightening strike

Got to be a good test of the machine protection system, at least