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Saturday 17.7. Access for QPS QHPS of magnet C34R5 repaired. 11:00 Injection 11:20 Compensator Pt 2 (SVC2) trip. EPC piquet suggests not to restart it. 12:00 Ramp Beam dumped early in the ramp due to FMCMs in IR2 (ALICE compensators). Apparently network glitch, not related to SVC2.
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Saturday 17.7 • Access for QPS • QHPS of magnet C34R5 repaired. • 11:00 Injection • 11:20 Compensator Pt 2 (SVC2) trip. EPC piquet suggests not to restart it. • 12:00 Ramp • Beam dumped early in the ramp due to FMCMs in IR2 (ALICE compensators). Apparently network glitch, not related to SVC2. • 15:00 Injection • Cleanup of the orbit at injection. Rms down to 0.1 mm wrt June reference. Corrector changes cleaned up. • 16:15 Ramp • Orbit diverged in the first GeVs and OFB switched itself off. Switch ON worked and orbit back to reference – Ouf ! Coincided with the loss of a BPM crate ? 8:30 meeting
Orbit in the ramp 8:30 meeting
RT corrections ramp 8:30 meeting
Saturday 17.7 • 18:30 Adjust - Colliding • Recorded details of non-closure corrections of Xing and separation collapse in order to incorporate them more consistently in the future. • Significant beam loss when switching on Xing angle (non-closure). Non-closure must be corrected since this will limit intensity increase (dump by BLM). • Stable beams declared with all luminosities at 0…. Moved back into adjust. • Corrections for separation had changed a lot. Found all optima rather quickly except for ALICE. • 19:20 Stable beams again • 22:00 finally found collisions in ALICE. There was a 0.5 mm H offset. • Comparing the orbits in stable beams over the past few fills revealed pretty large variations around IR1,2,5 ,8. This must be cleaned ! • In the background: • CO piquet had to replace a QPS gateway (transparently !). 8:30 meeting
Bunch 1 loss at start of fill = almost 50% 8:30 meeting
Sunday 18.7 • 01:10 : Beam dumped • Q6.L5 trip. Not understood. • 03:00 At injection level • Data subscription problems for a number of applications and systems. One rack in CCR was found not powered. Problems with servers cfc-ccr-gpdlrf and cfc-ccr-cgplbd. • 06:00 finally OK again after replacement of machine cfc-ccr-gpdlrf in the CCR by CO piquet. • 07:00 Injection • 08:15 Ramp for physics 13_8_8_8 8:30 meeting