LHC 2011 - latest news

Week 34: Machine coordinators: Gianluigi Arduini and Ralph Assmann

Luminosity production, 90m optics run and Machine Development

Adiabatically increase beam intensity

 

Day

Summary

Link to report from morning meeting

Monday 29th August 

·         09:00 Lost cryo maintain in Sector 78. Again problem on temperature sensor for RQTL9.R7B1. Access in Sector 78 again.

·         04:42 Beam dump due to collimator position in LSS7. End of MD#3 and preparation for technical stop.

·         06:00 Start of Technical Stop

8:30 meeting & MD report

Sunday 28th August

·         01:43 Cryo recover and start-precycle

·         02:48 Lost cryo maintain in MR2 - pre-cycle matching section again. In the shadow test of the collimator functions for the tight collimator settings.

·         04:15 Injection of B1. No Beam 2 problem due to vacuum problem in TI8 (some ion pumps stopped)

·         06:13 Trip of sector 67 (main quadrupole trip due to loss of communication with QPS controller MQ.24R6). Access to repair: F3 circuit breaker spurious opening

·         09:00 Lost cryo maintain in Sector 78. Again problem on temperature sensor for RQTL9.R7B1. Access in Sector 78 again.

·         15:20 Injection. MD beta*=1m - Part 2

9:00 meeting

Saturday 27th August

·         Cryo recovery in Sector 23. In the shadow intervention on temperature sensor for RQTL9.R7B1 (access from 13:30 to 20:30 for connector repair)

9:00 meeting

Friday 26th August

·         01:00 MD transverse damper emittance blow-up.

·         07:00 Collimator problem.

·         08:00 MD triplet aperture.

·         16:00 MD 25 ns injection

·         17:00-21:00 Trip due due to thunderstorms and recover

·         22:50 Lost cryogenics in Sector 23 due to a trip of the 3.3 kV

·         Cryo recovery in Sector 23

8:30 meeting & MD report

Thursday 25th August

·         05:00 MD beam instrumentation.

·         13:00 Short access for ADT. Several issues afterwards: IR8L triplet tripped, ADT issues.

·         18:40 MD long-range beam-beam. First fill lost during squeeze, second fill provided 1h time for measurements.

8:30 meeting & MD report

Wednesday 24th August

·         01:06 All TCTs aligned

·         04:53 All TOTEM vertical roman pots aligned. Problem with ALFA roman pot position reading.

·         05:16 Power glitch. Trip of compensators in point 2 and 8

·         Ramp-down and preparation of 1m beta* MD

·         START OF MD SESSION #3

·         07:00 MD beta*=1m

·         07:45 Squeezed to 1.5 m (1 pilot per beam)

·         08:15 Loading of functions and checks before squeezing to 1 m

·         09:15 Squeezed to 1 m OK. Start beta beating measurements.

·         18:30 Electrical glitch. Several sectors tripped. Recovery.

·         23:54 MD long bunch length.

8:30 meeting

LMC report

Tuesday 23th August

·         02:30 Reverted back to previous ADT firmware and prepare access for orbit corrector FGC

·         05:30 Ready to inject for RF study in preparation of the MD.  In parallel preparation of the settings for the 90 ms optics run.

·         09:00 Start 90 m optics run.

·         10:30 Ready for injection. Problems in the orbit acquisition due to the selected filling scheme with bunches of different intensity.

·         14:00 Fill with 5 bunches with 6x1010 p/bunch

·         15:00 Lost beam during the ramp due to a problem on an RF frequency distribution module requiring a reboot

·         17:00 refill after fixing problem with RF module

·         18:30 Beam dump during the squeeze due to a trip of a triplet orbit corrector. Traced back to a problem in LSA function trims

·         20:00 Filling (3 bunches with ~7-8x1010 p/bunch)

·         21:47 90 m beta*

·         23:47 Beams colliding at all IPs and start TCT alignment

8:30 meeting

Monday 22nd August

·         00:07 stable beams

·         18:00 Programmed dump. End of physics #2040. ~83 pb-1 in ~18 hours

·         Test of the coupling functions for the squeeze to 1 m.

·         Trip of Sector 78 during the ramp-down (noise on QPS board)

·         Loading of new damper firmware for controlled emittance blow-up, RF measurements without beams and ATLAS access during recovery form Sector 78 trip

·         21:00 Ready for injection but problem with injection kicker (generator not charging the PFNs Beam 2) and later with LBDS (tracking fault on Beam 1)

·         22:45 Ready for injection. Issues with the transverse damper settings and with the RF of beam 1

·         Problems with RF Module 1 Beam 1 (2 trips) and MKB generator Beam2

8:30 meeting