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Thursday 10.6. Plan for the day: Night from Wed-Thursday: Ramp optimization. Morning: Controlled longitudinal emittance blow-up. Afternoon: Transverse feedback system commissioning. Night: Squeeze commissioning & preparation for collimation set-up at 3.5 TeV
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Thursday 10.6 • Plan for the day: • Night from Wed-Thursday: Ramp optimization. • Morning: Controlled longitudinal emittance blow-up. • Afternoon: Transverse feedback system commissioning. • Night: Squeeze commissioning & preparation for collimation set-up at 3.5 TeV • 06:30 : Medium intensity ramp – 8E10 • Looks much better than one nominal bunch. • Emittances of 3mm at start of ramp, 5mm at end of ramp. • Colliding at b* = 10 m. Coupling around 2 10-3. • Stable collisions, lifetimes 25-125 hours. B2V emittance to 10mm, other planes stable. • Luminosity 4 1028cm-2 s-1 in ATLAS and CMS (1 colliding pair). with 1.2 1029cm-2 s-1 with b* = 3.5 m could reach 1 1030cm-2 s-1 with 8 bunches 8 1010, b* = 3.5 m. 8:30 meeting
Orbit and Tune Correction during Ramp 8:30 meeting
Bunch length during ramp 8:30 meeting
1 Colliding pair of 8E10, b* 10 m 8:30 meeting
Thursday 10.6 • 10:15 : End of fill • 12:00 : New injection7e10 per beam for RF studies • 13:13: MPS problem in PS, no beams for a while • 15:30: PS and SPS ready again for new injections • 15:50: SPS preparing for high intensity beams with increased long. emittance • 16:45: Injection of high intensities into LHC • 17:20 : New ramp – 8E10 • 17:30: lost 2B2 and 3B2 cavities leading to bad beam lifetime (7h compared to 170 h for Beam1) and increased bunch length. • Beam2 cavities keep tripping after resets! • continuous losses in IR3 and IR7 (large emittances) • The B1 bunch length evolved as designed and reached 1.5 ns. 8:30 meeting
Thursday 10.6 • 18:45 : Collapsing separation bumps: • ATLAS: BRAN rate = 550 Hz; Luminosity 3.8 1028cm-2 s-1 • CMS: BRAN rate = 770 Hz; Luminosity 3.8 1028 cm-2 s-1 • Attempt to collapse separation bump in ALICE leads to beam losses • 19:30 : Dumped both beams to prepare new fill for damper studies • Beam dump of Beam 2 gives XPOC error. Probably due to un-bunched beam caused by RF problems • 20:43 : QPS not OK for RB.A23 • requires access; QPS communication problem on MB29.R2 • tracked down to a bad contact access finished at 00:00. • 01:30 ; Pre-Cycle finished 8:30 meeting
Bunch length during second ramp 8:30 meeting
Beam losses during second ramp 8:30 meeting
1 Colliding pair of 8E10, second ramp 8:30 meeting
Friday 10.6 • 02:30 : Starting Damper studies • The new firmware for the multi-bunch feedback had a negative side effect (programming of coarse delay not working) which means one cannot advance with it. • 05:00 : Start preparing new fill for Collimator setup • problems with PS-SPS synchronization jitter • some problems in SPS with longitudinal beam blow-up • Program for today: • Morning: Collimator setup at 3.5 TeV. • Afternoon: Controlled longitudinal emittance blow up on ramp. • Night: Transverse damper studies • Saturday morning: Collimatorsetup at 3.5 TeV. 8:30 meeting
Friday 10.6 • Open Issues: • RCD.A45B2 and RCBXH1.R1 require QPS board change (running on board B) • MKI in IR2 and IR8 require access for updating the timing synchronization 8:30 meeting
Program for the next 2 weeks ✔ LMC report