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Tuesday 16 th October - morning

Tuesday 16 th October - morning. 10:00 Start Roman Pot insertion 11:00 Beam dumped BLM on RP triggered with RP at 31 sigmas … eek Fill 3188: 105 pb -1 in 6h58m 12:00 ALICE BCM dump (without beam) power supply of BCM system C has been exchanged in the shadow of ramp-down

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Tuesday 16 th October - morning

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  1. Tuesday 16th October - morning • 10:00 Start Roman Pot insertion • 11:00 Beam dumped • BLM on RP triggered with RP at 31 sigmas… eek • Fill 3188: 105 pb-1 in 6h58m • 12:00 ALICE BCM dump (without beam) • power supply of BCM system C has been exchanged in the shadow of ramp-down • Problem signing post mortem – software issue • No beam from PS followed by serious beam quality issues in injectors • tweaks in SPS, cause found in PS (two extraction supplies not pulsing), back-out tweaks in SPS etc… • 15:00 Injecting for ADT high-bandwidth tests LHC status

  2. Tuesday 16th October - afternoon • ADT high bandwidth • Successful test ramp squeeze and collide… • 16:30 beam dumped - Spurious EE opening of RB.A67 • Energy Extraction team access IP6 (UA67) to replace cards on the RB.A67 EE system • Access for ATLAS in the shadow • 20:15 EE team out • 20:30 Start pre-cycle • 22:00 Beam in • Some delay at start ramp: BBQ FESA server down • 23:50 Stable beams fill 3191 • Initial luminosity: 6.5e33 cm-2s-1 LHC status

  3. Wednesday 17th October – early morning • 00:42 Beams lost • RF Low level off on cavity L2B2 (external veto) due to control interlock - RF piquet didn't find anything wrong… • Fill 3191: 16 pb-1 in 47 minutes • 03:20 Stable beams • Fill 3192: initial luminosity 6.66e33 cm-2s-1 • Brightness from injectors lower at the moment – investigations on-going • Still in… LHC status

  4. The night in colour LHC status

  5. High bandwidth transverse damper Wolfgang Hofle, Daniel Valuch A test ramp with 6+144 bunches per beam was made using ADT settings with increased bandwidth (developed originally for the 25 ns run) and flat response in frequency. These settings were loaded after injection when preparing for the ramp. The loss of overall gain (estimated -15 dB) was over compensated (+24 dB) so effectively the gain in the ramp, squeeze and in collisions should also have been 9 dB higher than what is nominally used. The Q kicker was used at 450 GeV to estimate the damping time and confirm the above (offline analysis required). The beams were brought in collision, indicating no apparent issue with these settings. BRAN luminosities indicated roughly the same per bunch luminosity as in a normal Physics fill, detailed analysis required. LHC status

  6. BQBBQLHC Some issues with BBQ state control changes… Stephen Jackson & Ralph Steinhagen • Modified Setting, Acquisition & Measurement properties from FESA servers • Changed name of field from deviceState to usedByOFC • Categorized fields in Setting property. In the case of performing a partial-set only on the usedByOFC and bunchGating fields, the acquisition will not be stopped while the new settings are applied. • Added the usedByOFC field to the Measurement and Acquisition properties • Added a new field bunchSelected to the Measurement and Acquisition properties. At the moment, this is always zero • New version deployed & tested on all front-ends. LHC status

  7. Vacuum oscillations near to MKI8D Cryogenics revert beam screen regulation set points change LHC status

  8. Klystron saturation during the ramp Themistoklis Mastoridis, Philippe Baudrenghien There was a warning from Big Sister towards the end of the last ramp. After a quick investigation with Philippe, we can see that two klystrons (2B2, 6B2) were in saturation. We believe that the cavity tuner loop did not converge to the optimal position with just a single batch in the machine. The behaviour seems to be better with a full machine, but we would still like to optimize the tuner settings with beam tomorrow to increase our margin of operation. Optimal cavity tuning will be even more important for the planned fills with smaller bunch lengths. Our tuners are clearly not adjusted perfectly, (else it should not make a difference with 144b or 1380b), resulting in a slightly different position. It works fine with 1380b. Nevertheless that indicates that margins are too small. RF want to fine-adjust the tuners (1 hour at injection with nominal beams, machine half full). LHC status

  9. Pending operational development Batch-by-batch longitudinal blowup at injection. Gated tune measurement with reduced damper gain on first 6 bunches Shorter bunches at injection with adiabatic voltage increase after filling Fill(s) with shorter bunch length (impedance, heating…). Strategy to be defined. Ideally down to 1 ns. LHC status

  10. Pending access requests • Access system PAD UJ43 (S.di Luca). • B2 BGI : UX451 for a camera replacement. 1 hour. • BSRT : tunnel. No time estimate. • BBQ: UA43/7. Short. • LVDT TDI Pt2. Tunnel, 2 hours. • LBDS MKD-F-B1: check PC and generator. UA63. • Radmon installation between Q5 and Q6 at IP1. 1 hour access, few hours pre-warning. Impact 21253 / D. Macina. • ATLAS : ~3 hours. Impact 21251. • ALICE LHC status

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